Rev.1.2-12
Seiko Instruments Inc. 1
The S-8355/56/57/58 Series is a CMOS step-up switching regulatorwhich mainly consists of a reference voltage source, an oscillationcircuit, an error amplifier, a phase compensation circuit, a PWMcontrol circuit (S-8355/57) and a PWM/PFM switching control circuit(S-8356/58). With an external low-ON-resistance Nch Power MOS,this product is applicable to applications requiring high efficiency andhigh output current.The S-8355/57 Series realizes low ripple, high efficiency, andexcellent transient characteristics with the PWM control circuit whoseduty ratio can vary from 0 % to 83 % (from 0 % to 78 % for 250 kHzand 300 kHz models), the best-designed error amplifier and phasecompensation circuits.The S-8356/58 Series switches its operation to the PFM control circuitwhose duty ratio is 15 % with to the PWM/PFM switching controlcircuit under a light load and to prevent decline in the efficiency by ICoperation current.
! Features
• Low voltage operation: Start-up is guaranteed from 0.9 V(IOUT =1 mA )• Low current consumption: During operation: 25.9 µA (3.3 V, 100 kHz, typ.)
During shutdown: 0.5 µA (max.)• Duty ratio: Built-in PWM/PFM switching control circuit (S-8356/58)
15 to 83 % (100 kHz models), 15 to 78 % (250 kHz and 300 kHz models)• External parts: coil, diode, capacitor, and transistor• Output voltage: 0.1 V step setting is available between 1.5 and 6.5 V (for VDD/VOUT separate types) or
2.0 and 6.5 V (for other than VDD/VOUT separate types). Accuracy of ±2.4 %.• Oscillation frequency: 100, 250, and 300 kHz• Soft start function: 6 ms (100 kHz, typ.)• Shutdown function
!"Packages
• SOT-23-3 (Package code : MP003-A)• SOT-23-5 (Package code : MP005-A)• SOT-89-3 (Package code : UP003-A)• 6-Pin SNB(B) (Package code : BD006-A)
! Applications
• Power supplies for portable equipment such as digital cameras, electronic notebooks, and PDAs• Power supplies for audio equipment such as portable CD/MD players• Constant voltage power supplies for cameras, video equipment, and communications equipment• Power supplies for microcomputers
S-8355/56/57/58 SeriesULTRA-SMALL PACKAGE PWM CONTROL,PWM/PFM SWITCHING CONTROLSTEP-UP SWITCHING REGULATOR
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
2 Seiko Instruments Inc.
! Block Diagram
! Selection Guide
1. Function List
Product name Controlsystem
Switchingfrequency
(kHz)
Shutdownfunction
VDD/VOUTseparate
typePackage Application
S-8355KxxMC PWM 100 Yes Yes SOT-23-5 Application which needs an variable output voltage and a shutdown function
S-8355LxxMC/BD 250 Yes Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage, a shutdown functionand a thin coil
S-8355MxxMC/BD 300 Yes Yes SOT-23-5 / 6 Pin-SNB(B) Application which needs an variable output voltage, a shutdown functionand a thin coil
S-8357BxxMC 100 Yes SOT-23-5 Application which needs a shutdown functionS-8357BxxMA 100 SOT-23-3 Application with an unnecessary shutdown functionS-8357BxxUA 100 SOT-89-3 Application with an unnecessary shutdown functionS-8357ExxMC 100 Yes SOT-23-5 Application which adjusts output voltage by external resistorS-8357FxxMC/BD 300 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs a shutdown function and a thin coilS-8357GxxMC/BD 300 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage and a thin coilS-8357HxxMC/BD 250 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs a shutdown function and a thin coil
S-8357JxxMC/BD 250 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage with an external resistorand a thin coil
S-8356KxxMC PWM/PFMswitching 100 Yes Yes SOT-23-5 Application which needs an variable output voltage and a shutdown function
S-8356LxxMC/BD 250 Yes Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage, a shutdown functionand a thin coil
S-8356MxxMC/BD 300 Yes Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage, a shutdown functionand a thin coil
S-8358BxxMC 100 Yes SOT-23-5 Application which needs a shutdown functionS-8358BxxMA 100 SOT-23-3 Application with an unnecessary shutdown functionS-8358BxxUA 100 SOT-89-3 Application with an unnecessary shutdown functionS-8358ExxMC 100 Yes SOT-23-5 Application which adjusts output voltage by external resistorS-8358FxxMC/BD 300 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs a shutdown function and a thin coilS-8358GxxMC/BD 300 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage and a thin coilS-8358HxxMC/BD 250 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs a shutdown function and a thin coil
S-8358JxxMC/BD 250 Yes SOT-23-5 / 6-Pin SNB(B) Application which needs an variable output voltage with an external resistorand a thin coil
Figure 1 Block Diagram
-+
IC internalpower supply
VOUT
EXT
VSS
PWM or PWM /PFM switching control circuit
Soft startbuilt-in referencepower supply
Phasecompensationcircuit
Oscillation Circuit
-+
EXT
VOUT
VSS
VDD
IC internalpowersupply
PWM or PWM /PFM switching control circuit
Phasecompensationcircuit
Soft startbuilt-in referencepower supply
Oscillation Circuit
-+
IC internalpower supply
VOUT
VSS
PWM or PWM /PFM switching control circuit
Soft startbuilt-in referencepower supply
EXT
Oscillation Circuit
ON/ OFF
Phasecompensationcircuit
-+
Soft startbuilt-in referencepower supply
IC internalpowersupply
VOUT
EXT
VSSPhasecompensationcircuit
VDD
Oscillation Circuit
ON/ OFF
PWM or PWM /PFM switching control circuit
(1) S-8357/58 Series B, H, F Type (No shutdown function) (2) S-8357/58 Series B, H, F Type (Shutdown function included)
(3) S-8357/58 Series E, J, G Type (VDD/VOUT separate type) (4) S-8355/56 Series K, L, M Type
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 3
2. Product Name
S-835 x x xx xx - xxx - Tx
IC direction in tape specificationT2 ; SOT-23-3, SOT-23-5, SOT-89-3TF ; 6-Pin SNB(B)
Product name (abbreviation)Package name (abbreviation)
MA ; SOT-23-3MC ; SOT-23-5UA ; SOT-89-3BD ; 6 Pin-SNB(B)
Output voltage (× 10) 18 to 50 (1.8 to 5.0 V)Product type
B ; Normal product, fOSC= 100 kHz (S-8357/58)H ; Normal product, fOSC = 250 kHz (S-8357/58)F ; Normal product, fOSC = 300 kHz (S-8357/58)E ; VDD/VOUT separate type, fOSC = 100 kHz (S-8357/58)J ; VDD/VOUT separate type, fOSC = 250 kHz (S-8357/58)G ; VDD/VOUT separate type, fOSC = 300 kHz (S-8357/58)K ; Shutdown function + VDD/VOUT separate type, fOSC = 100 kHz (S-8355/56)
L ; Shutdown function + VDD/VOUT separate type, fOSC = 250 kHz (S-8355/56)M ; Shutdown function + VDD/VOUT separate type, fOSC = 300 kHz (S-8355/56)
Control system5 or 7 ; PWM control6 or 8 ; PWM/PFM switching control
3. Package and Function List by Product Type
Series name Type Package name(abbreviation)
ShutdownfunctionYes / No
VDD/VOUTseparate type
Yes / No
S-8355 SeriesS-8356 Series
K, L, M(Shutdown function + VDD/VOUT separate type) K = 100 kHz, L = 250 kHz, M = 300 kHz
MCBD
Yes Yes
MAUA
NoB, H, F(Normal product) B = 100 kHz, H = 250 kHz, F = 300 kHz MC
BDYes
No
S-8357 SeriesE, J, G(VDD/VOUT separate type) E = 100 kHz, J = 250 kHz, G = 300 kHz
MCBD
No Yes
MAUA
NoB, H, F(Normal product) B = 100 kHz, H = 250 kHz, F = 300 kHz MC
BDYes
No
S-8358 SeriesE, J, G(VDD /VOUT separate type) E=100 kHz, J=250 kHz, G=300 kHz
MCBD
No Yes
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
4 Seiko Instruments Inc.
4. Product Name List
Output voltage (V) S-8355KxxMC Series S-8355MxxBD Series S-8355MxxMC Series
1.8 S-8355K18MC-NAD-T2 S-8355M18BD-MCD-TF S-8355M18MC-MCD-T2
5.0
Output voltage (V) S-8356KxxMC Series S-8356MxxBD Series S-8356MxxMC Series
1.8 S-8356K18MC-NED-T2 S-8356M18BD-MED-TF S-8356M18MC-MED-T2
5.0 S-8356M50MC-MFJ-T2
Output voltage (V) S-8357BxxMC Series S-8357FxxMC Series S-8357GxxMC Series
3.3 S-8357B33MC-NIS-T2 S-8357F33MC-MGS-T2
5.0 S-8357B50MC-NJ J-T2 S-8357F50MC-MHJ-T2 S-8357G50MC-MJJ-T2
Output voltage (V) S-8358BxxMC Series S-8358GxxMC Series
3.3 S-8358B33MC-NQS-T2
5.0 S-8358B50MC-NRJ-T2 S-8358G50MC-MNJ-T2
Please consult our sales person for products with an output voltage other than specified above.
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 5
! Pin Assignment
Figure 2 Pin Assignment
Without shutdown function, VDD/VOUT non-separate typeProducts: S-8357/58 Series B, H, F TypePackages: SOT-23-3Pin No. Pin Name Functions
1 VOUT Output voltage pin and IC power supply pin2 VSS GND pin3 EXT External transistor connection pin
Without shutdown function, VDD/VOUT non-separate typeProducts: S-8357/58 Series B, H, F TypePackages: SOT-89-3Pin No. Pin Name Functions
1 VSS GND pin2 VOUT Output voltage pin and IC power supply pin3 EXT External transistor connection pin
With shutdown function, VDD/VOUT non-separate typeProducts: S-8357/58 Series B, H, F TypePackages: SOT-23-5Pin No. Pin Name Functions
1 ON/OFFShutdown pin“H”: Normal operation (step-up oepration)“L”: Stop step-up (whole circuit stop)
2 VOUT Output voltage pin and IC power supply pin3 (N.C.)4 VSS GND pin5 EXT External transistor connection pin
With shutdown function, VDD/VOUT non-separate typeProducts: S-8357/58 Series B, H, F TypePackages: 6-Pin SNB(B)Pin No. Pin Name Functions
1 (N.C.)
2 ON/OFFShutdown pin“H”: Normal operation (Step-up oepration)“L”: Stop step-up (Whole circuit stop)
3 VOUT Output voltage pin and IC power supply pin4 EXT External transistor connection pin5 (N.C.)6 VSS GND pin
Without shutdown function, VDD/VOUT separate typeProducts: S-8357/58 Series E, J, G TypePackages: SOT-23-5Pin No. Pin Name Functions
1 VOUT Output voltage pin2 VDD IC power supply pin3 (N.C.)4 VSS GND pin5 EXT External transistor connection pin
Without shutdown function, VDD/VOUT separate typeProducts: S-8357/58 Series E, J, G TypePackages 6-Pin SNB(B)Pin No. Pin Name Functions
1 (N.C.)2 VOUT Output voltage pin3 VDD IC power supply pin4 EXT External transistor connection pin5 (N.C.)6 VSS GND pin
With shutdown function, VDD/VOUT separate typeProducts: S-8355/56 Series K, L, M TypePackages: SOT-23-5Pin No. Pin Name Functions
1 VOUT Output voltage pin2 VDD IC power supply pin
3 ON/OFFShutdown pin“H”: Normal operation (Step-up oepration)“L”: Stop step-up (Whole circuit stop)
4 VSS GND pin5 EXT External transistor connection pin
With shutdown function, VDD/VOUT separate typeProducts: S-8355/56 Series K, L, M TypePackages: 6-Pin SNB(B)Pin No. Pin Name Functions
1 ON/OFFShutdown pin“H”: Normal operation (Step-up oepration)“L”: Stop step-up (Whole circuit stop)
2 VOUT Output voltage pin3 VDD IC power supply pin4 EXT External transistor connection pin5 (N.C.)6 VSS GND pin
SOT-23-5321
5 4Top view
SOT-23-3
32
1Top view
SOT-89-3321
Top view
6-Pin SNB(B)321
6 45
Top view
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
6 Seiko Instruments Inc.
! Absolute Maximum Ratings (Unless otherwise specified: Ta=25°C)
Parameter Symbol Ratings UnitVOUT pin voltage VOUT VSS−0.3 to VSS+12ON/OFF pin voltage*1 VON/OFF VSS−0.3 to VSS+12VDD pin voltage*2 VDD VSS−0.3 to VSS+12
B, H, F type VSS−0.3 to VOUT+0.3EXT pin voltage VEXT Others VSS−0.3 to VDD+0.3
V
EXT pin current IEXT ±80 mASOT-89-3 500SOT-23-5 250SOT-23-3 150Power dissipation PD
6-Pin SNB(B) 90
mW
Operating temperature Topr −40 to +85Storage temperature Tstg −40 to +125 °C
Note *1. With shutdown function *2. For VDD/VOUT separate types
Caution. Although the IC contains protection circuit against static electricity, excessive static electricity orvoltage which exceeds the limit of the protection circuit should not be applied to.
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 7
! Electrical Characteristics100kHz types (S-835xBxx, S-835xExx, S-835xKxx)
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit Testcircuit
Output voltage VOUT VOUT(S)×0.976 VOUT(S) VOUT(S)
×1.024Input voltage VIN − − 10 2Operation start voltage VST1 IOUT = 1 mA − − 0.9 VOscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1Operation holdingvoltage VHLD
IOUT = 1 mA, Measured by decreasing VIN voltagegradually 0.7 − − 2
S-835xx15 to 19 − 14.0 23.4S-835xx20 to 29 − 19.7 32.9S-835xx30 to 39 − 25.9 43.2S-835xx40 to 49 − 32.6 54.4S-835xx50 to 59 − 39.8 66.4
Current consumption 1 ISS1 VOUT = VOUT(S) ×0.95
S-835xx60 to 65 − 47.3 78.9S-835xx15 to 19 − 5.6 11.1S-835xx20 to 29 − 5.8 11.5S-835xx30 to 39 − 5.9 11.8S-835xx40 to 49 − 6.1 12.1S-835xx50 to 59 − 6.3 12.5
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 6.4 12.8Current consumptionduring shutdown(with shutdown function)
ISSS VON/OFF = 0 V − − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −S-835xx20 to 24 −6.2 −12.3 −S-835xx25 to 29 −7.8 −15.7 −S-835xx30 to 39 −10.3 −20.7 −S-835xx40 to 49 −13.3 −26.7 −S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −S-835xx15 to 19 9.5 19.0 −S-835xx20 to 24 12.6 25.2 −S-835xx25 to 29 15.5 31.0 −S-835xx30 to 39 19.2 38.5 −S-835xx40 to 49 23.8 47.6 −S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 VIN = VOUT(S) ×0.4 to × 0.6 − 30 60Load regulation ∆VOUT2 IOUT = 10 µA to VOUT(S) / 50 × 1.25 − 30 60 mV
Output voltagetemperature coefficient
∆ V O U T
∆ Ta • V O U T
Ta = − 40°C to + 85°C − ±50 − ppm/°C2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 85 100 115 kHzMax. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 75 83 90PWM/PFM switchingduty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24 %
VSH Measured the oscillation at EXT pin 0.75 − −VSL1 When VOUT ≥1.5 V − − 0.3
Shutdown pin inputvoltage (for shutdownfunction built-in type) VSL2
Judged the stop ofoscillation at EXT pin When VOUT<1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1Shutdown pin inputcurrent (for shutdownfunction built-in type) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 3.0 6.0 12.0 msEfficiency EFFI − 86 − % 2
External parts
- Coil : CDRH6D28-470 of Sumida Corporation- Diode : RB461F(Schottky type) of Rohm Co., Ltd.- Capacitor : F93(16 V, 47 µF tantalum type) of Nichicon Corporation- Transistor : CPH3210 of Sanyo Electric Co., Ltd.- Base resister (Rb) : 1.0 kΩ- Base capacitor (Cb) : 2200 pF (ceramic type)
VIN = VOUT(S) × 0.6 applied, IOUT = VOUT(S) / 50 ΩThe shutdown function built-in type: ON/OFF pin is connected to VOUTVDD/VOUT separate type : VDD pin is connected to VOUT pin
Remark VOUT (S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.Caution VDD/VOUT separate type:
Step-up operation is performed from VDD= 0.8 V.However, 1.8≤VDD ≤10 V is recommended to stabilize the output voltage and oscillation frequency.(VDD ≥1.8 V must be applied for products with a set value of less than 1.9 V.)
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
8 Seiko Instruments Inc.
250kHz types (S-835xHxx, S-835xJxx, S-835xLxx) (Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit Testcircuit
Output voltage VOUT VOUT(S)×0.976 VOUT(S) VOUT(S)
×1.024Input voltage VIN − − 10 2Operation start voltage VST1 IOUT = 1 mA − − 0.9 VOscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1Operation holdingvoltage VHLD
IOUT = 1 mA, Measured by decreasing VIN voltagegradually 0.7 − − 2
S-835xx15 to 19 − 28.9 48.2S-835xx20 to 29 − 42.7 71.1S-835xx30 to 39 − 58.0 96.7S-835xx40 to 49 − 74.5 124.1S-835xx50 to 59 − 92.0 153.4
Current consumption 1 ISS1 VOUT = VOUT(S) × 0.95
S-835xx60 to 65 − 110.5 184.2S-835xx15 to 19 − 8.7 17.3S-835xx20 to 29 − 8.8 17.6S-835xx30 to 39 − 9.0 18.0S-835xx40 to 49 − 9.2 18.3S-835xx50 to 59 − 9.3 18.6
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 9.5 19.0Current consumptionduring shutdown(with shutdown function)
ISSS VON/OFF = 0 V − − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −S-835xx20 to 24 −6.2 −12.3 −S-835xx25 to 29 −7.8 −15.7 −S-835xx30 to 39 −10.3 −20.7 −S-835xx40 to 49 −13.3 −26.7 −S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −S-835xx15 to 19 9.5 19.0 −S-835xx20 to 24 12.6 25.2 −S-835xx25 to 29 15.5 31.0 −S-835xx30 to 39 19.2 38.5 −S-835xx40 to 49 23.8 47.6 −S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 VIN = VOUT(S) × 0.4 to × 0.6 − 30 60Load regulation ∆VOUT2 IOUT = 10 µA to VOUT(S) / 50× 1.25 − 30 60 mV
Output voltagetemperature coefficient
∆ V O U T
∆ Ta • V O U T
Ta = − 40°C to + 85°C − ±50 − ppm/°C2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 212.5 250 287.5 kHzMax. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 70 78 85PWM/PFM switchingduty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24 %
VSH Measured the oscillation at EXT pin 0.75 − −VSL1 When VOUT ≥1.5 V − − 0.3
Shutdown pin inputvoltage (for shutdownfunction built-in type) VSL2
Judged the stop ofoscillation at EXT pin When VOUT <1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1Shutdown pin inputcurrent (for shutdownfunction built-in type) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 1.5 3.0 6.0 msEfficiency EFFI − 85 − % 2
External parts
- Coil : CDRH6D28-220 of Sumida Corporation- Diode : RB461F(Schottky type) of Rohm Co., Ltd.- Capacitor : F93(16 V, 47 µF tantalum type) of Nichicon Corporation- Transistor CPH3210 of Sanyo Electric Co., Ltd.- Base resister (Rb) : 1.0 kΩ- Base capacitor (Cb) : 2200 pF (ceramic type)
VIN = VOUT(S) × 0.6 applied, IOUT = VOUT(S) / 50 ΩThe shutdown function built-in type : ON/OFF pin is connected to VOUTVDD/VOUT separate type : VDD pin is connected to VOUT pin
Remark VOUT (S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.Caution VDD/VOUT separate type:
Step-up operation is performed from VDD =0.8 V.However, 1.8≤ VDD ≤10 V is recommended to stabilize the output voltage and oscillation frequency.(VDD ≥1.8 V must be applied for products with a set value of less than 1.9 V.)
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 9
300kHz types (S-835xFxx, S-835xGxx, S-835xMxx)
(Unless otherwise specified: Ta = 25°C)
Parameter Symbol Conditions Min. Typ. Max. Unit Testcircuit
Output voltage VOUT VOUT(S)×0.976 VOUT(S) VOUT(S)
×1.024Input voltage VIN − − 10 2Operation start voltage VST1 IOUT = 1 mA − − 0.9 VOscillation start voltage VST2 No external parts, voltage applied to VOUT − − 0.8 1Operation holdingvoltage VHLD
IOUT = 1 mA, Measured by decreasing VIN voltagegradually 0.7 − − 2
S-835xx15 to 19 − 33.8 56.4S-835xx20 to 29 − 50.3 83.9S-835xx30 to 39 − 68.6 114.4S-835xx40 to 49 − 88.4 147.4S-835xx50 to 59 − 109.4 182.4
Current consumption 1 ISS1 VOUT = VOUT(S) × 0.95
S-835xx60 to 65 − 131.6 219.3S-835xx15 to 19 − 9.7 19.4S-835xx20 to 29 − 9.9 19.7S-835xx30 to 39 − 10.0 20.0S-835xx40 to 49 − 10.2 20.4S-835xx50 to 59 − 10.4 20.7
Current consumption 2 ISS2 VOUT = VOUT(S) + 0.5
S-835xx60 to 65 − 10.5 21.0Current consumptionduring shutdown(with shutdown function)
ISSS VON/OFF = 0 V − − 0.5
µA
S-835xx15 to 19 −4.5 −8.9 −S-835xx20 to 24 −6.2 −12.3 −S-835xx25 to 29 −7.8 −15.7 −S-835xx30 to 39 −10.3 −20.7 −S-835xx40 to 49 −13.3 −26.7 −S-835xx50 to 59 −16.1 −32.3 −
IEXTH VEXT = VOUT − 0.4
S-835xx60 to 65 −18.9 −37.7 −S-835xx15 to 19 9.5 19.0 −S-835xx20 to 24 12.6 25.2 −S-835xx25 to 29 15.5 31.0 −S-835xx30 to 39 19.2 38.5 −S-835xx40 to 49 23.8 47.6 −S-835xx50 to 59 27.4 54.8 −
EXT pin output current
IEXTL VEXT = 0.4 V
S-835xx60 to 65 30.3 60.6 −
mA
1
Line regulation ∆VOUT1 VIN = VOUT(S) × 0.4 to × 0.6 − 30 60Load regulation ∆VOUT2 IOUT = 10 µA to VOUT(S) / 50 × 1.25 − 30 60 mV
Output voltagetemperature coefficient
∆ V O U T
∆ Ta • V O U T
Ta = − 40°C to + 85°C − ±50 − ppm/°C2
Oscillation frequency fOSC VOUT = VOUT(S) × 0.95 255 300 345 kHzMax. duty ratio MaxDuty VOUT = VOUT(S) × 0.95 70 78 85PWM/PFM switchingduty ratio (S-8356/58) PFMDuty VIN = VOUT(S) − 0.1 V, no load 10 15 24 %
VSH Measured the oscillation at EXT pin 0.75 − −VSL1 When VOUT ≥1.5 V − − 0.3
Shutdown pin inputvoltage (for shutdownfunction built-in type) VSL2
Judged the stop ofoscillation at EXT pin When VOUT<1.5 V − − 0.2
V
ISH Shutdown pin = VOUT(S) × 0.95 −0.1 − 0.1Shutdown pin inputcurrent (for shutdownfunction built-in type) ISL Shutdown pin = 0 V −0.1 − 0.1
µA
1
Soft start time tSS 1.5 3.0 6.0 msEfficiency EFFI − 85 − % 2
External parts
- Coil : CDRH6D28-220 of Sumida Corporation- Diode : RB461F(Schottky type) of Rohm Co., Ltd.- Capacitor : F93(16 V, 47 µF tantalum type) of Nichicon Corporation- Transistor : CPH3210 of Sanyo Electric Co., Ltd.- Base resister (Rb) : 1.0 kΩ- Base capacitor (Cb) : 2200 pF (ceramic type)
VIN = VOUT(S) × 0.6 applied, IOUT = VOUT(S) / 50 ΩThe shutdown function built-in type: ON/OFF pin is connected to VOUTVDD/VOUT separate type : VDD pin is connected to VOUT pin
Remark VOUT (S) specified above is the set output voltage value, and VOUT is the typical value of the output voltage.Caution VDD/VOUT separate type:
Step-up operation is performed from VDD = 0.8 V. However, 1.8≤VDD ≤10 V is recommended to stabilize the output voltage and oscillation frequency. (VDD ≥1.8 V must be applied for products with a set value of less than 1.9 V.)
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
10 Seiko Instruments Inc.
! Test Circuits
! Operation
1. Step-up DC/DC Converter
The S-8355/57 Series is a DC/DC converter using a pulse width modulation method (PWM) and
features a low current consumption.
In conventional PFM DC/DC converters, pulses are skipped at low output load current, causing
fluctuation in ripple frequency of the output voltage, with the result of increase in ripple voltage.
In S-8355/57 Series, the switching frequency does not change, although the pulse width changes from
0 % to 83 % (78 % for F, G, H, J, L, and M type) corresponding to each load current. The ripple voltage
generated from switching can thus be removed easily through the filter because the switching frequency is
constant.
S-8356/58 Series is a DC/DC converter that atuomatically switches a pulse width modulation method
(PWM) and a pulse frequency modulation method (PFM), dependeing on the load current and features a
low current consumption. Especially, the series is a highly efficient DC/DC converter at an output current of
around 100 µA.
2.
0.1µF
V-
+
-
+
(VDD)
VSS
VOUT
(ON/OFF)
EXT
Rb
Cb
Figure 3 Test Circuits 1,2
1.
VSS
VOUT
(VDD)
EXT
(ON/OFF)Oscilloscope
0.1µF -
+
A
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 11
In conventional constant-duty PFM DC/DC converters, pulses are skipped at low output load current,
causing fluctuation in ripple frequency of the output voltage, with the result of increase in ripple voltage.
The S-8356/58 Series operates under the PWM control with the pulse width duty changing from 15 % to 83
% (78 % for F, G, H, J, L, and M Series) at high output load current.
On the other hand, the S-8356/58 Series operates under the PFM control with the pulse width duty fixed
at 15 % at low output load current, and pulses are skipped at low output load current according to the load
current and output to the switching transister. The oscillation circuit thus oscillates intermittently so that the
resultant lower self-consumption could prevent the efficiency from reducing at low load current. A
switching point from the PWM control to the PFM control depends on the external devices (coil, diode,
etc.), input voltage and output voltage.
For this IC, the built-in soft start circuit controls a rush current and overshoot of the output voltage when
powering on or the ON/OFF pin is turned to “H” level.
Shutdown pin: Stops or starts step-up operation.
(Only for SOT-23-5 package products of B, H, F, K, L and M type and for 6-pin SNB(B) package
products.)
Turning the shutdown pin to “L” level stops operation of all the internal circuits and reduces the
current consumption significantly.
DO NOT use the shutdown pin in floating state because it has a structure shown in Figure 4
and
is not pulled up or pulled down internally. DO NOT apply voltage of between 0.3 V and 0.75 V to
the shutdown pin because applying such voltage increases the current consumption. If the
shutdown pin is not used, connect it to VOUT (VDD for K, L and M type) pin.
The shutdown pin doesn’t have hysteresis.
Shutdownpin
CR oscillation circuit Output voltage
“H” Operation Fixed
“L” Stop ≅ VIN*
* Voltage obtained by extracting the voltage drop due
to DC resistance of the inductor and the diode
forward voltage from VIN.
Figure 4 Shutdown pin structure
VSS
VOUT (VDD for K, L and M types)
ON/OFF
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
12 Seiko Instruments Inc.
Figure 5 Step-up switching regulator circuit for basic equations
CLM1
D
VOUT
CONTVIN
L
+
-EXT
VSS
The following are basic equations [(1) through (7)] of the step-up switching regulator (see Figure 5.)Voltage at CONT pin at the moment M1 is turned ON (current IL flowing through L is zero), VA:
The change in IL over time:
Integration of the above equation :
IL flows while M1 is ON (tON). The time of tON is determined by the oscillation frequency of the OSC.
The peak current (IPK) after tON:
The energy stored in L is represented with 1/2 • L (IPK)2 .
When M1 is turned OFF (tOFF), the energy stored in L is transmitted through a diode to the output capacitor.
Then, reverse voltage (VL) is generated:
The voltage at CONT pin rises only by VOUT+VD.
The change in the current (IL) flowing through the diode into VOUT during tOFF:
= = ........................................................... (2)
IL= ............................................................................ (3)
IPK= • ton ................................................................... (4)
= = ...................................................... (6)
....................................................................... (5)
........................................................................................... (1)
(VS : Non-saturated voltage of M1)
VA=VS
dILdt
VL
LVIN−VS
L
VIN−VS
L
VIN−VS
L
dILdt
VL
L
VOUT+VD−VIN
L
VL= (VOUT+VD) − VIN
(VD : Diode forward voltage)
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 13
Integration of the above equation is as follows:
During tON, the energy is stored in L and is not transmitted to VOUT. When receiving output current (IOUT)
from VOUT, the energy of the capacitor (CL) is consumed. As a result, the pin voltage of CL is reduced, and
goes to the lowest level after M1 is turned ON (tON). When M1 is turned OFF, the energy stored in L is
ransmitted through the diode to CL, and the voltage of CL rises drastically. VOUT is a time function indicates
the maximum value (ripple voltage: VP−P) when the current flowing through into VOUT and load current (IOUT)
match.
Next, the ripple voltage is found out as follows:
IOUT vs t1 (time) from when M1 is turned OFF (after tON) to when VOUT reaches the maximum level:
When M1 is turned ON (after tOFF), IL=0 (when the energy of the inductor is completely transmitted):
Based on equation (7),
When substituting equation (10) for equation (9),
Electric charge ∆Q1 which is charged in CL during t1 :
When substituting equation (12) for equation (9):
A rise in voltage (VP−P) due to ∆Q 1:
= .........................................................(10)
t1= tOFF − • tOFF .................................................................. (11)
∆Q1= IPK − (IPK − IOUT) • t1 = • t1 .......................... (13)
IOUT = IPK− • t1 ................................................ (8)
∴ t1= (IPK−IOUT) • .............................................. (9)
IL= IPK− • t ......................................................(7)
VP-P= = • • t1 .................................. (14)
VOUT+VD−VIN
LIPK
tOFF
IPK
IOUT
VOUT+VD−VIN
L
VOUT+VD−VIN
L
∆Q1 = ∫ ILdt = IPK • ∫ dt −............................. • ∫ tdt
= IPK • t1 − • t12 .................................... (12)VOUT+VD−VIN
L 21
t10
VOUT+VD−VIN
L0t1
0t1
L
VOUT+VD−VIN
21
2IPK+IOUT
CL
∆Q1
CL
12
IPK+IOUT
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
14 Seiko Instruments Inc.
VP-P= • + • RESR ................ (16)
When taking into consideration IOUT to be consumed during t1 and ESR (Equivalent Series Resistance) of
CL, namely RESR:
When substituting equation (11) for equation (15):
Therefore to reduce the ripple voltage, it is important that the capacitor connected to the output pin has a
large capacity and a small ESR.
! External parts selection for DC/DC converter
The relationship between major characteristics of the step-up circuit and characteristics parameters of the
external parts are shown in Figure 6.
For higher efficiency?For larger output current?
Operation efficiency Stand-by efficiencyFor smaller ripple voltage?
Figure 6 Relationship between major characterstics of the step-up circuit and external parts
VP-P= = • • t1 + • RESR − ...... (15)
smaller inductance larger inductance
smaller DC resistance of inductor
larger output capacitance
With MOS FET, smallerinput capacitanceWith MOS FET, smaller ON resistance
With bipolar transistor, smaller externalresistance Rb
With bipolar transistor,larger external resistanceRb
2IPK
(IPK−IOUT)2
CL
tOFF
2IPK+IOUT
larger output capacitance
CL
∆Q1
CL
12
IPK+IOUT
CL
IOUT • t12
IPK+IOUT
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 15
1. Inductor
An inductance has strong influence on maximum output current IOUT and efficiency η.
Figure 7 shows the relation between IOUT, and η characteristics to L of S-8355/56/57/58.
The peak current (IPK) increases by decreasing L and the stability of a circuit improves and IOUT increases.
If L is furthermore made small, efficiency falls and in running short, IOUT decreases. (Based on the current
drive capability of external switching transistor.)
The loss of IPK by the switching transistor decreases by increasing L and the efficiency becomes
maximum at a certain L value. Further increasing L decreases efficiency due to the loss of DC resistance
of the coil. Also, IOUT decreases, too.
Oscillation frequency is higher, smaller one can be choosed and also makes coil smaller.
The recommended inductances are 22 to 100 µH inductor for B, E,and K type, 4.7 to 47 µH inductor for
F, G, H, J, L, and M type.
Choose a value for L by refering to the reference data because the maximum output current is due to the
input voltage in an actual case. Choose an inductor so that IPK does not exceed the allowable current.
Exceeding the allowable current of the inductor causes magnetic saturation, remarkable low efficiency and
destruction of the IC chip due to a large current.
IPK in uncontinuous mode is caluculated from the following equatuon:
fosc = oscillation frequency, VD ≅ 0.4 V.
IPK =2 IOUT (VOUT+VD−VIN)
fOSC • L(A) .............................. (17)
CDRH6D28 VOUT=5.0 V, VIN=3.0 V
F, G, H, J, L, M Type
Recommended range
IOUT
η
4.7 47
Efficienccydecreases
IOUT decreases
IPK increases
Coil size:smaller
Efficienccydecreases
IOUTdecreases
IPK decreases
Coil size:bigger
L (µH)
Figure 7 L-IOUT and η characteristics
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
16 Seiko Instruments Inc.
2. Diode
Use an external diode that meets the following requirements:
• Low forward voltage: (VF<0.3 V)
• High switching speed: (50 ns max.)
• Reverse voltage: VOUT + VF or more
• Rated current: IPK or more
3. Capacitor (CIN, CL)
A capacitor at the input side (CIN) improves the efficiency by reducing the power impedance and
stabilizing the input current. Select a CIN value according to the impedance of the power supply used.
A capacitor at the output side (CL) is used for smoothing the output voltage. For step-up types, the
output voltage flows intermittently to the load current so that step-up types need a larger capacitance than
step-down types. Therefore, select an appropriate capacitor depending on the ripple voltage that
increases in case of a higher output voltage or a higher load current. The capacitor value should be 10 µF
minimum.
Select an appropriate capacitor with an ESR (Equivalent Series Resistance) for stable output voltage. A
stable range of the volatge at this IC depends on the ESR. Although the inductance (L) is also a factor, an
ESR of 30 mΩ to 500 mΩ draws out the characteristics. However, the best ESR may depend on L,
capacitance, wiring and applications (output load). Therefore, fully evaluate ESRs under an actual
condition to determine the best value.
Figure 19 of Application Circuit 2 shows an example of circuit that uses a ceramic capacitor and the
external resiatance (ESR) for your reference.
4. External transistor
A bipolar (NPN) transistor or an enhancement (N-channel) MOS FET transistor can be used as external
transistor.
4.1 Bipolar (NPN) transistor
A circuit example using a bipolar transistor (NPN), Sanyo Electric Co., Ltd. CPH3210 (hFE =200 to 560)
is shown in Figure 10. The hFE value and the Rb value determine the driving capacity to increase the output
current using a bipolar transistor. A peripheral circuit example of the transistor is shown in Figure 8.
IPK
Nch
Pch
Rb
VOUT
EXT
Cb2200 pF
1 kΩ
(VDD for E, G, J, K, L, M type)
Figure 8 External transistor peripheral
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 17
1 kΩ is recommended for Rb. Rb is selected from the following caluculation. Caluculate the necessary
base current (Ib) from the bipolar transistor hFE using Ib =IPK/hFE.
A small Rb increases output current, however, the efficiency decreases. The current flows pulsating and
there is voltage drop due to wiring resistance in an actual circuit, therefore the optimum Rb value should be
determined by experiment.
A speed-up capacitor (Cb) connected in parallel with Rb resistance as shown in Figure 8 decreases the
switching loss and improves the efficiency.
Cb is caluculated from the following equatuon:
However, in practice, the optimum Cb value also varies with the characteristics of the bipolar transistor to
be employed. Therefore, determine the optimum value through experiments.
4.2 Enhancement MOS FET type
Figure 9 is a circuit example using Sanyo Electric Co., Ltd.
MPH3401 MOS FET transistor (N-channel).
For a MOS FET, an N-channel power MOS FET should be
used. Because the gate voltage and current of the external
power MOS FET are supplied from the stepped up output
voltage VOUT, the MOS FET is driven more effectively.
Depending on the MOS FET you use in your device, there
is a chance of a current overrun at power ON. Thoroughly
test all settings with your device before deciding on which
one to use. Also, try to use a MOS FET with the input
capacitance of 700 pF or less.
Since the ON resistor of the MOS FET might depend on the difference between the output voltage VOUT
and the threshold voltage of MOS FET, and affect the output current as well as the efficiency, the threshold
voltage should be low. When the output voltage is low, the circuit operates only when the MOS FET has
the threshold voltage lower than the output voltage.
Figure 9 Circuit example using MOS FET
2π • Rb • fOSC • 0.71
Cb≤
VOUT
EXT
VOUT
(ON / OFF)
VSS
(VDD)
-
+-
+
for E,G,J,K,L,and M types)( Rb= VDD−0.7Ib | IEXTH |
0.4Rb= | IEXTH |
0.4Ib
VOUT−0.7
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
18 Seiko Instruments Inc.
5. VDD/VOUT separate types (E,G,J,K,L,and M type)
The E, G, J, K, L, and M type are applicable to the following applications because the power pin for the IC
chip and the VOUT pin for the output voltage are separated:
(1) When changing the output voltage with an external resistance.
(2) When outputting the high voltage such as +15 V or +20 V.
Choose the products in the following table according to applications for (1) to (2) above.
Output voltage VCC 1.8 V≤VCC<5 V 5 V≤VCC Reference circuit
S-835xx18 Yes Yes Application circuit 1 (Figure 17)S-835xx50 Yes Application circuit 1 (Figure 17)
Connection to VDD pin VIN or VCC VIN
The operational precautions are follows:
1) This IC starts to step-up operation at VDD=0.8 V but set 1.8≤VDD≤10 V to stabilize the output voltage
and frequency of the oscillator.
(Input the voltage of 1.8 V or more for VDD pin for all the products of setting less than 1.9 V)
The input voltage of 1.8 V or more for VDD pin allows the connection of the VDD pin to either input
power pin VIN or output power pin VOUT.
2) Choose external resistors RA and RB not to affect to the output voltage with the consideration of the
impedance between the VOUT and VSS pins in the IC chip.
Internal resistance between the VOUT and VSS pins are as follows:
(1) S-835xx18→5.6 MΩ to 14.9 MΩ
(2) S-835xx20→5.2 MΩ to 12.3 MΩ
(3) S-835xx50→3.8 MΩ to 10.4 MΩ
3) Attach the capacitor (CC) in parallel to RA resistance when unstable action such as the oscillation of
the output voltage occurs. Calculate CC from the following equatuon:
2 • π • RA • 20kHz
1CC(F) =
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 19
(1) S-8357BxxMA, S-8357BxxUAS-8358BxxMA, S-8358BxxUA
(2) S-8357BxxMC, S-8357FxxMC/BD, S-8357HxxMC/BDS-8358BxxMC, S-8358FxxMC/BD, S-8358HxxMC/BD
! Standard Circuits
SD
CL
VIN
L
1 kΩ
VOUT
VSS
EXT
-
+-
+
-
+PWM or PWM/PFM switchingcontrol circuit
Soft start built-in reference power supply
Phasecompensatingcircuit
Oscillation circuit
IC internal powersupply
2200 pF
CIN
Remark. The power supply for IC
chip is from VOUT pin.
Figure 10 Standard circuit (1)
Figure 11 Standard circuit (2)
Remark. The power supply for
IC chip is from VOUT pin.
-
+-
+
SD
1 kΩ
VIN
LVOUT
VSS
EXT
-
+
2200 pF
CIN
ON/OFF
CL
PWM or PWM/PFM switchingcontrol circuit
Soft start built-in reference power supply
Phasecompensatingcircuit
Oscillation circuit
IC internal powersupply
(3) S-8357ExxMC, S-8357GxxMC/BD, S-8357JxxMC/BDS-8358ExxMC, S-8358GxxMC/BD, S-8358JxxMC/BD
Remark. The power supply
for IC chip is from VDD pin.
Figure 12 Standard circuit (3)
-
+-
+
-
+
CL
L
SD
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
PWM or PWM/PFM switchingcontrol circuit
Soft start built-in reference power supply
Phasecompensatingcircuit
Oscillation circuit IC internalpowersupply
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
20 Seiko Instruments Inc.
(4) S-8357EXXMC, S-8357GXXMC/BD, S-8357JXXMC/BDS-8358EXXMC, S-8358GXXMC/BD, S-8358JXXMC/BD
(5) S-8355KXXMC, S-8355LXXMC/BD, S-8355MXXMC/BDS-8356KXXMC, S-8356LXXMC/BD, S-8356MXXMC/BD
-
+
-
+
-
+
CL
ON/OFF
L
SD
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
PWM or PWM/PFM switchingcontrol circuit
Soft startbuilt-in referencepower supply
Phasecompensatingcircuit
Oscillation circuit IC internalpowersupply
Remark.The power supply
for IC chip
Figure 14 Standard circuit (5)
(6) S-8355KXXMC, S-8355LXXMC/BD, S-8355MXXMC/BDS-8356KXXMC, S-8356LXXMC/BD, S-8356MXXMC/BD
-
+
-
+
CL
ON/OFF
L
SD
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
-
+PWM or PWM/PFM switchingcontrol circuit
Soft startbuilt-in referencepower supply
Phasecompensatingcircuit
Oscillation circuit IC internalpowersupply
Remark.The power supply
for IC chip
Figure 15 Standard circuit (6)
Remark. The power supply
for IC chip is from VDD pin.
Figure 13 Standard circuit (4)
SD
1 kΩ
VIN
VOUT
VSS
EXT
2200 pF
CIN
VDD
-
+
-
+
CL
L
-
+PWM or PWM/PFM switchingcontrol circuit
Soft startbuilt-in referencepower supply
Phasecompensatingcircuit
Oscillation circuit IC internalpowersupply
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 21
! Power Dissipation of Package
! Precautions
• Mount external capacitors, a diode, and a coil as close as possible to the IC.
• Unique ripple voltage and spike noise occur in switching regulators. Because they largely depend on the
coil and the capacitor used, check them using an actually mounted model.
• Make sure dissipation of the switching transistor (especially at a high temperature) does not exceed the
allowable power dissipation of the package.
• The performance of this IC varies depending on the design of the PCB patterns, peripheral circuits and
external parts. Thoroughly test all settings with your device. Also, try to use recommended external parts.
If not, contact your SII sales person.
• Seiko Instruments Inc. shall not be responsible for any patent infringement by products including S-
8355/56/57/58 Series in connection with the method of using S-8355/56/57/58 Series in such products,
the specification of such products, or the country of destination thereof.
Figure 16 Power dissipation of the package (before mounting)
0 50 100 150
600
400
200
0
PowerDissipation
PD
(mW)
Ambient Temperature Ta (°C)
SOT-23-3
SOT-89-3
6-Pin SNB(B)
SOT-23-5
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
22 Seiko Instruments Inc.
! Application Ciruits
1. LCD Power Supply
The following examples are an application power supply circuit (15 V/20 V output) to drive LCD panels, and
its characteristics.
Outputvoltage IC L type name TR type name SD type name CL Ra Rb Cc Output
characteristics
(1) 15 V S-8356M50 CDRH5D18-220 MCH3405 MA2Z748 F93(20 V,10 µF) 580 kΩ 300 kΩ 15 pF (1-a),(1-b)(2) 20 V S-8356M50 CDRH5D18-220 FDN337N MA729 F93(25 V,10 µF) 575 kΩ 200 kΩ 15 pF (2-a),(2-b)
12
13
14
15
16
0.01 0.1 1 10 100
VIN=3 VVIN=5 VVIN=7 V
14
16
18
20
22
0.01 0.1 1 10 100
VIN=3 VVIN=5 VVIN=7 V
Output Current IOUT [mA]
(2-b) Output Current vs. Output Voltage
Out
put V
olta
ge V
OU
T [V
]
(1-b) Output Current vs. Output Voltage
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
0
20
40
60
80
100
0.01 0.1 1 10 100
VIN=3 VVIN=5 VVIN=7 V
0
20
40
60
80
100
0.01 0.1 1 10 100
VIN=3 VVIN=5 VVIN=7 V
Output Current IOUT [mA]
(2-a) Output Current vs. Efficiency
Effic
ienc
y η
[%]
(1-a) Output Current vs. Efficiency
Output Current IOUT [mA]
Effic
ienc
y η
[%]
Figure 18 LCD power supply output characteristics
Figure 17 Power supply circuit for LCD
S-8356M50
EXT
VOUT
VSS
VDD
ON/OFF
VOUT
SD
CLCC
L
RB
RA
TR
CINVIN
-
++
-
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 23
2. Ceramic CapacitorIf using small ESR parts such as ceramic capacitors to the output capacitance, attach a resistor (R1)
corresponding to the ESR in series to the ceramic capacitor (CL) as shown in the following circuit.
R1 may depend on L, capacitance, wiring and applications (output load).
The follwong examples are a circuit using R1 =100 mΩ, output voltage =3.3 V, output load =500 mA and its
characteristics.
IC L type name TR type name SD type name CL
(ceramic capacitor) R1 Output characteristics
(1) S-8357F33 CDRH6D28-220 FDN335N M1FH3 10 µF×2 pieces 100 mΩ (1-a),(1-b),(1-c)(2) S-8358B50 CDRH6D28-470 FDN335N M1FH3 10 µF×2 pieces 100 mΩ (2-a),(2-b),(2-c)
EXT VOUT
VSS
VOUTSD
CL
L
R1TR
VIN CIN
Figure 19 Circuit using ceramic capacitor
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
24 Seiko Instruments Inc.
0
20
40
60
80
100
120
0.01 0.1 1 10 100 1000
VIN=0.9 VVIN=1.8 VVIN=2.7 V
0
20
40
60
80
100
120
0.01 0.1 1 10 100 1000
VIN=2 VVIN=3 VVIN=4 V
3.28
3.29
3.30
3.31
3.32
0.01 0.1 1 10 100 1000
VIN=0.9 VVIN=1.8 VVIN=2.7 V
5.03
5.04
5.05
5.06
5.07
0.01 0.1 1 10 100 1000
VIN=2 VVIN=3 VVIN=4 V
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
VIN=0.9 VVIN=1.8 VVIN=2.7 V
0
20
40
60
80
100
0.01 0.1 1 10 100 1000
VIN=2 VVIN=3 VVIN=4 V
Output Current IOUT [mA]
(2-a) Output Current vs. EfficiencyEf
ficie
ncy
η [%
]
(1-a) Output Current vs. Efficiency
Output Current IOUT [mA]
Effic
ienc
y η
[%]
Output Current IOUT [mA]
(2-b) Output Current vs. Output Voltage
Out
put V
olta
ge V
OU
T [V
]
(1-b) Output Current vs. Output Voltage
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
Output Current IOUT [mA]
(2-c) Output Current vs. Ripple Voltage
Rip
ple
Volta
ge
Vr [m
V]
(1-c) Output Current vs. Ripple Voltage
Output Current IOUT [mA]
Rip
ple
Volta
ge
Vr [m
V]
Figure 20 Ceramic capacitor circuit output characteristics
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 25
! Example of Major Temperature Characteristics (Ta = −40 to 85°C)
ISS1 vs. Ta (VOUT=3.3 V, fosc=100 kHz)
0
10
20
30
40
50
-40 -20 0 20 40 60 80 100Ta [°C]
ISS1[µA]
ISS1 vs. Ta (VOUT=3.3V, fosc=300 kHz)
0
10
20
30
40
50
-40 -20 0 20 40 60 80 100Ta [°C]
ISS1[µA]
ISS2 vs. Ta (VOUT=3.3 V, fosc=300 kHz)
0
2
4
6
8
10
-40 -20 0 20 40 60 80 100Ta [°C]
ISS2[µA]
ISS2 vs. Ta (VOUT=3.3 V, fosc=100 kHz)
0
2
4
6
8
10
-40 -20 0 20 40 60 80 100Ta [°C]
ISS2[µA]
ISSS vs. Ta (VOUT=3.3 V, fosc=100 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
-40 -20 0 20 40 60 80 100Ta [°C]
ISSS[µA]
ISSS vs. Ta (VOUT=3.3 V, fosc=300kHz)
0.0
0.2
0.4
0.6
0.8
1.0
-40 -20 0 20 40 60 80 100Ta [°C]
ISSS[µA]
IEXTH vs. Ta (VOUT=3.3 V, fosc=300 kHz)
-
-10
-20
-30
-40
-50
-60
-40 -20 0 20 40 60 80 100Ta [°C]
IEXTH[mA]
0
IEXTL vs. Ta (VOUT=3.3 V, fosc=300 kHz)
0
10
20
30
40
50
60
-40 -20 0 20 40 60 80 100Ta [°C]
IEXTL[mA]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
26 Seiko Instruments Inc.
FOSC vs. Ta (VOUT=3.3 V, fosc=100 kHz)
50
75
100
125
150
-40 -20 0 20 40 60 80 100Ta [°C]
fOSC[kHz]
FOSC vs. Ta (VOUT=3.3 V, fOSC =300 kHz)
200
250
300
350
400
-40 -20 0 20 40 60 80 100Ta [°C]
fOSC[kHz]
MaxDuty vs. Ta (VOUT=3.3 V, fosc=100 kHz)
70
75
80
85
90
-40 -20 0 20 40 60 80 100Ta [°C]
MaxDuty[%]
MaxDuty vs. Ta (VOUT=3.3 V, fosc=300 kHz)
70
75
80
85
90
-40 -20 0 20 40 60 80 100Ta [°C]
MaxDuty[%]
VSH vs. Ta (VOUT=3.3 V, fosc=300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
-40 -20 0 20 40 60 80 100Ta [°C]
VSH[V]
VSL1 vs. Ta (VOUT=3.3 V, fosc=300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
-40 -20 0 20 40 60 80 100Ta [°C]
VSL1[V]
VSL2 vs. Ta (VOUT=3.3 V, fosc=300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
-40 -20 0 20 40 60 80 100Ta [°C]
VSL2[V]
PFMDuty vs. Ta (VOUT=3.3 V, fosc=100 kHz)S-8356/58 Series
5
10
15
20
25
-40 -20 0 20 40 60 80 100Ta [°C]
PFMDuty[%]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 27
TSS−Ta (VOUT=3.3 V, fosc=100 kHz)
0
2
4
6
8
-40 -20 0 20 40 60 80 100Ta [°C]
TSS[ms]
VST1−Ta (VOUT=3.3 V, fosc=100 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
-40 -20 0 20 40 60 80 100Ta [°C]
VST1[V]
TSS−Ta (VOUT=3.3 V, fosc=300 kHz)
0
2
4
6
8
-40 -20 0 20 40 60 80 100Ta [°C]
TSS[ms]
VST2−Ta (VOUT=3.3 V, fosc=300 kHz)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
-40 -20 0 20 40 60 80 100Ta [°C]
VST2[V]
VOUT−Ta (VOUT=3.3 V, fosc=100 kHz)
3.20
3.25
3.30
3.35
3.40
-40 -20 0 20 40 60 80 100Ta [°C]
VOUT[V]
VOUT−Ta (VOUT=3.3 V, fosc=300 kHz)
3.20
3.25
3.30
3.35
3.40
-40 -20 0 20 40 60 80 100Ta [°C]
VOUT[V]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
28 Seiko Instruments Inc.
! Example of Major Power Supply Dependence Characteristics (Ta=25°C)
ISS1,2 vs. VDD
(VOUT =3.3 V, Fosc =300 kHz, Ta =25°C)
0
10
20
30
40
50
0 2 4 6 8 10VDD[V]
ISS1,2[µA]
ISSS vs. VDD
(VOUT =3.3 v, fosc =300 kHz, Ta =25°C)
0.0
0.2
0.4
0.6
0.8
1.0
0 2 4 6 8 10VDD[V]
ISSS[µA]
IEXTH vs. VDD
-
-20
-40
-60
-80
-100
0 2 4 6 8 10VDD[V]
IEXTH[mA]
0
IEXTL vs. VDD
0
20
40
60
80
100
0 2 4 6 8 10VDD[V]
IEXTL[mA]
fOSC vs. VDD (fOSC =300 kHz)
60
120
180
240
300
360
0 2 4 6 8 10VDD[V]
fOSC
[kHz]
fOSC vs. VDD (fOSC =100 kHz)
20
40
60
80
100
120
0 2 4 6 8 10VDD[V]
fOSC
[kHz]
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10VDD[V]
V OUT[V]
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10VDD[V]
VOUT[V]
VOUT vs. VDD(VOUT=3.3 V, fOSC=100 kHz, VDD separate type)
VIN=1.98 V, IOUT=66 mA
VOUT vs. VDD(VOUT=3.3 V, fOSC=300 kHz, VDD separate type)
VIN=1.98 V, IOUT=66 mA
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 29
! Output Waveforms1. S-8358B33MC
1. IOUT=1 mA
-25 -20 -15 -10 -5 0 5 10 15 20 25time [µs]
4
2
0
3.40
3.35
3.30
3.25
2. IOUT=20 mA
-25 -20 -15 -10 -5 0 5 10 15 20 25time [µs]
4
2
0
3.40
3.35
3.30
3.25
3. IOUT=100 mA
-25 -20 -15 -10 -5 0 5 10 15 20 25time [µs]
4
2
0
3.40
3.35
3.30
3.25
4. IOUT=200 mA
-25 -20 -15 -10 -5 0 5 10 15 20 25time [µs]
4
2
0
3.40
3.35
3.30
3.25
2. S-8358F33MC
4. IOUT =200 mA
-10 -8 -6 -4 -2 0 2 4 6 8 10time [µs]
4
2
0
3.40
3.35
3.30
3.25
1. IOUT =1 mA
-10 -8 -6 -4 -2 0 2 4 6 8 10time [µs]
4
2
0
3.40
3.35
3.30
3.25
3. IOUT =100 mA
-10 -8 -6 -4 -2 0 2 4 6 8 10time [µs]
4
2
0
3.40
3.35
3.30
3.25
2. IOUT =10 mA
-10 -8 -6 -4 -2 0 2 4 6 8 10time [µs]
4
2
0
3.40
3.35
3.30
3.25
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
OutputVoltage
[0.05 V/div]
CONTVoltage[2 V/div]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
30 Seiko Instruments Inc.
! Examples of Transient Response characteristics1. Powering ON (VIN ;0 V→2.0 V )
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VIN
[V]
0
2
4VOUT
[V]
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VIN
[V]
0
2
4VOUT
[V]
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VIN
[V]
0
2
4VOUT
[V]
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VIN
[V]
0
2
4VOUT
[V]
2. Responses of Shutdown pin (ON/OFF ;0 V→2.0 V )
V ON/OFF (100 kHz, IOUT=1 mA)
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VON/OFF[V]
0
2
4VOUT
[V]
ON/OFF (100 kHz, IOUT=100 mA)
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VON/OFF[V]
0
2
4VOUT
[V]
ON/OFF (300 kHz, IOUT=1 mA)
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VON/OFF[V]
0
2
4VOUT
[V]
ON/OFF (300 kHz, IOUT=100 mA)
0
2
-1 0 1 2 3 4 5 6 7 8 9time [ms]
VON/OFF[V]
0
2
4VOUT
[V]
Powering ON (100 kHz, IOUT=1 mA )
Powering ON (300 kHz, IOUT=1 mA )
Powering ON (100 kHz, IOUT=100 mA )
Powering ON (300 kHz, IOUT=100 mA )
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 31
3. Load Fluctuations
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8time [ms]
3.00
3.20
3.40
3.60
VOUT[0.2 V/div]
100 µA
IOUT
100 mA
-10 0 10 20 30 40 50 60 70 80 90time [ms]
3.20
3.40
3.60
3.80
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
-0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5time [ms]
3.00
3.20
3.40
3.60
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
-10 0 10 20 30 40 50 60 70 80 90time [ms]
3.20
3.40
3.60
3.80
VOUT
[0.2 V/div]
100 µA
IOUT
100 mA
4. Power Voltage Fluctuations
=100mA)V
=100mA)V
1.5
2.0
2.5
3.0
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8time [ms]
3.25
3.30
3.35
3.40
3.45
VIN [V]VOUT
[V]
1.5
2.0
2.5
3.0
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8time [ms]
3.25
3.30
3.35
3.40
3.45
VIN [V]VOUT
[V]
1.5
2.0
2.5
3.0
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8time [ms]
3.25
3.30
3.35
3.40
3.45
VIN [V]
[V]
1.5
2.0
2.5
3.0
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8time [ms]
3.25
3.30
3.35
3.40
3.45
VIN [V] VOUT
[V]VOUT
Power Voltage Fluctuation (100 kHz, IOUT=100 mA)
VIN=1.98 V→2.64 V
Load Fluctuation (100 kHz, IOUT; 100 µA→100 mA)
Load Fluctuation (300 kHz, IOUT; 100 µ A→100 mA)
Load Fluctuation (100 kHz, IOUT; 100 mA→100 µA)
Load Fluctuation (300 kHz, IOUT; 100 mA→100 µA)
Power Voltage Fluctuation (100 kHz, IOUT=100 mA)
VIN=2.64→1.98 V
Power Voltage Fluctuation (300 kHz, IOUT=100 mA)
VIN=1.98 V→2.64 V
Power Voltage Fluctuation (300 kHz, IOUT=100 mA)
VIN=2.64 V→1.98 V
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
32 Seiko Instruments Inc.
! Reference DataUse reference data to choose the external parts. The reference data here give you the procedure to choose
the recommended external parts for various applications and its characteristics data.
1. Reference Data for External Components
Table 1. Efficiency vs. Output characteristics and Output Voltage vs. Output Current characteristicsfor external components
No. Productname
Oscillationfrequency
Outputvoltage
Controlsystem Inductor Transister Diode Output capacitor
(1) S-8357F33 300 kHz 3.3 V PWM CDRH104R-220 FDN335N M1FH3 F93(16 V,47 µF)×2(2) S-8357F50 300 kHz 5.0 V PWM ↑ ↑ ↑ ↑(3) S-8356M50 300 kHz 5.0 V PWM/PFM ↑ ↑ ↑ ↑(4) S-8357B33 100 kHz 3.3 V PWM CDRH104R-470 ↑ ↑ ↑(5) S-8358B33 100 kHz 3.3 V PWM/PFM ↑ ↑ ↑ ↑(6) S-8357B50 100 kHz 5.0 V PWM ↑ ↑ ↑ ↑(7) S-8356M50 300 kHz 5.0 V PWM/PFM CDRH8D28-220 FDN335N M1FH3 F93(16 V,47 µF)(8) S-8357B33 100 kHz 3.3 V PWM CDRH8D28-470 ↑ ↑ ↑(9) S-8358B33 100 kHz 3.3 V PWM/PFM ↑ ↑ ↑ ↑
(10) S-8357B50 100 kHz 5.0 V PWM ↑ ↑ ↑ ↑(11) S-8357F33 300 kHz 3.3 V PWM CDLP120-220 MCH3405 MA2Z748 F92(6.3 V,47 µF)(12) S-8356M50 300 kHz 5.0 V PWM/PFM ↑ ↑ ↑ ↑
The properties of external parts are shown below.
Table 2. Properties of external parts
Part Product name Manufacturer CharacteristicsInductor CDRH104R-220 Sumida Corporation 22 µH, DCR*1 =93 mΩ, Imax*2 =2.9 A, Height =4.0 mm
CDRH104R-470 47 µH, DCR*1 =128 mΩ, Imax*2 =2.1 A, Height =4.0 mmCDRH8D28-220 22 µH, DCR1) =95 mΩ, Imax*2 =1.6 A, Height =3.0 mmCDRH8D28-470 47 µH, DCR*1 =190 mΩ, Imax*2 =1.15 A, Height =3.0 mm
CXLP120-220 Sumitomo SpecialMetals Co., Ltd. 22 µH, DCR*1 =590 mΩ, Imax*2 =0.55 A, Height =1.0 mm
Diode M1FH3 Shindengen ElectricManufacturing Co., Ltd. VF
*3 =0.3V, IF*4 =1.5 A
MA2Z748 Matsushita ElectricIndustrial Co., Ltd. VF
*3 =0.4V, IF*4 =0.3 A
F93 Nichicon Corporation 16 V, 47 µFCapacitor(Output capacitance) F92 6.3 V, 47 µFTransister(Nch FET) FDN335N Fairchild Semiconductor
Japan Ltd.Vdss*5 =20 Vmax, Vgss*6 =8 Vmax, Ciss*7 =310 pF,Id*8 =1.5 A (Vgs*9 =2.5 V)
MCH3405 Sanyo Electric Co., Ltd. Vdss*5 =20 Vmax, Vgss*6 =10 Vmax, Ciss*7 =280 pF,Id*8 =0.5 A (Vgs*9 =1.8 V)
*1. DC resistance, *2. Maximum allowable current, *3. Forward voltage, *4. Forward current, *5. Drain-source voltage,*6. Gate-source voltage, *7. Input capacitance, *8. Drain current, *9 Gate-source voltage
Caution. The values shown in the characteristics column of Table 2 above are based on the materials provided by eachmanufacturer, however, consider the characteristics of the original materials when using the above products.
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 33
2. Reference Data 1
The data of (a) Output current vs. efficiency characteristics and (b) Output current vs. output voltage
characteristics under conditions of (1) to (12) shown in Table 1 are shown below.
(1) S-8357F33
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
20
40
60
80
100
VIN=0.9 V VIN=1.8 V VIN=2.7 V
0.1 1 10 100 1000Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]O
utpu
t Vol
tage
VO
UT
[V]
(2) S-8357F50
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
20
40
60
80
100
1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
0.1Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
(3) S-8356M50
20
40
60
80
100
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
34 Seiko Instruments Inc.
(4) S-8357B33
20
40
60
80
100
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
(5) S-8358B33
20
40
60
80
100
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
(6) S-8357B50
20
40
60
80
100
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 35
(7) S-8356M50
20
40
60
80
100
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
](8) S-8357B33
0
20
40
60
80
100
0.1 1 10 100 1000
VIN=0.9V VIN=1.8V VIN=2.7V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
(9) S-8358B33
20
40
60
80
100
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
36 Seiko Instruments Inc.
(10) S-8357B50
20
40
60
80
100
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
(b) Output Current vs.Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
](11) S-8357F33
3.0
3.1
3.2
3.3
3.4
3.5
0.1 1 10 100 1000
IN=0.9V IN=1.8V IN=2.7V
20
40
60
80
100
0.1 1 10 100 1000
IN=0.9V IN=1.8V IN=2.7V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
(12) S-8356M50
20
40
60
80
100
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
4.7
4.8
4.9
5.0
5.1
5.2
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
(b) Output Current vs. Output Voltage
Effic
ienc
y η
[%]
(a) Output Current vs. Efficiency
Output Current IOUT [mA]
Out
put V
olta
ge V
OU
T [V
]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORRev. 1.2-12 S-8355/56/57/58 Series
Seiko Instruments Inc. 37
3. Reference Data 2
The actual output current vs. ripple voltage characteristics data under conditions of (1) to (12) in Table 1
are shown below.
(1) S-8357F33 (2) S-8357F50
0
50
100
150
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
0
50
100
150
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
Output Current vs. Ripple Voltage
Rip
ple
Volta
ge V
r [m
V]
Output Current vs. Ripple Voltage
Output Current IOUT [mA]R
ippl
e Vo
ltage
Vr [
mV]
(3) S-8356M50 (4) S-8357B33
0
50
100
150
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
0
50
100
150
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
Output Current IOUT [mA]
Output Current vs. Ripple Voltage
Rip
ple
Volta
ge V
r [m
V]
Output Current vs. Ripple Voltage
Output Current IOUT [mA]
Rip
ple
Volta
ge V
r [m
V]
(5) S-8358B33 (6) S-8357B50
0
50
100
150
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
0
50
100
150
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
Output Current vs. Ripple Voltage
Rip
ple
Volta
ge V
r [m
V]
Output Current vs. Ripple Voltage
Outz put Current IOUT [mA]
Rip
ple
Volta
ge V
r [m
V]
ULTRA-SMALL PACKAGE PWM CONTROL, PWM/PFM SWITCHING CONTROL STEP-UP SWITCHING REGULATORS-8355/56/57/58 Series Rev. 1.2-12
38 Seiko Instruments Inc.
(7) S-8356M50 (8) S-8357B33
0
50
100
150
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
0
50
100
150
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
Output Current IOUT [mA]
Output Current vs. Ripple Voltage
Rip
ple
Volta
ge V
r [m
V]
Output Current vs. Ripple Voltage
Output Current IOUT [mA]
Rip
ple
Volta
ge V
r [m
V]
(9) S-8358B33 (10) S-8357B50
0
50
100
150
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
0
50
100
150
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
Output Current vs. Ripple Voltage
Rip
ple
Volta
ge V
r [m
V]
Output Current vs. Ripple Voltage
Output Current IOUT [mA]
Rip
ple
Volta
ge V
r [m
V]
(11) S-8357F33 (12) S-8356M50
0
50
100
150
0.1 1 10 100 1000
VIN=0.9 V VIN=1.8 V VIN=2.7 V
0
50
100
150
0.1 1 10 100 1000
VIN=2 V VIN=3 V VIN=4 V
Output Current IOUT [mA]
Output Current vs. Ripple Voltage
Rip
ple
Volta
ge V
r [m
V]
Output Current vs. Ripple Voltage
Output Current IOUT [mA]
Rip
ple
Volta
ge V
r [m
V]
2.9±0.2
0.95±0.1
1.9±0.2
+0.1 -0.050.16
0.4±0.1
0.25
+0.2 -0.62.8
0∼0.1
1
2 3
1.5
1.3max.1.1±0.1
T2
1.6±0.1
0.25±0.05
4.0±0.12.0±0.1
4.0±0.1
1.5+0.1 -0.05
1.1±0.1
2.85±0.2
Feed direction
1.75±0.1
3.5±0.1
8.0±0.23.05±0.2
No.:MP003-A-C-SD-1.0
21±0.5
2±0.2
(60°)(60°)
ø13±0.2
12.5max.
9.0±0.3
Winding core
ø60+1 -0
ø180+0 -3
n SOT-23-3MP003-A 990531
No.:MP003-A-P-SD-1.0
No.:MP003-A-R-SD-1.0
Unit:mmlDimensions
lTaping Specifications lReel Specifications1 reel holds 3000 ICs.
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• The information described herein is subject to change without notice.• Seiko Instruments Inc. is not responsible for any problems caused by circuits or diagrams described herein
whose related industrial properties, patents, or other rights belong to third parties. The application circuitexamples explain typical applications of the products, and do not guarantee the success of any specificmass-production design.
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