LED_DRIVERLED_DRIVERMB39C601MB39C601MB39C601MB39C601MB39C601MB39C601MB39C601MB39C601--------EVBEVBEVBEVBEVBEVBEVBEVB--------0404040404040404
Evaluation board ManualEvaluation board Manual
Fujitsu semiconductor limited confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITEDRev 1.0
Apr. 2012
ITEM MIN TYP MAX UNIT
Voltage range (RMS) VIN 184 230 265 VAC
Input current (RMS) IIN 53 mA
Output voltage VOUT 19 27 31 V
Output load current IOUT 350 mA
Ta = 25C , fac=60Hz
1. General 1. General DescriptionDescription
2. 2. Evaluation Board SpecificationEvaluation Board Specification
MB39C601-EVB-04 can light the LED, when the LED load is connected
with the output and the AC source is impressed to the input.
LED load: 350mA / 6-10 pieces in series
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED1/ 15
Output current ripple Iripple 120 mApp
Switching frequency fsw 90 kHz
Efficiency 87 %
Power Factor pf 0.90
ITEM MIN TYP MAX UNIT
Voltage range (RMS) VIN 184 230 265 VAC
Input current (RMS) IIN 51 mA
Output voltage VOUT 19 27 31 V
Output load current IOUT 350 mA
Output current ripple Iripple 128 mApp
Switching frequency fsw 90 kHz
Efficiency 87 %
Power Factor pf 0.92
Ta = 25C , fac=50Hz
Pin Name Description
TP1 AC line input (+)
TP2 LED output (+)
TP3 AC line input (-)
TP4 Dummy load test point
TP5 LED return point (-)
TP6 Flyback switch node
TP7 Dimmer conduction angle detection
TP8 Scaled TRIAC conduction angle
TP9 VDD of MB39C601
TP10 Transformer zero energy detection
TP11 Loop injection point for Gain/Phase measurement
3. Pin Descriptions3. Pin Descriptions
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED2/ 15
TP11 Loop injection point for Gain/Phase measurement
(1) Test Equipment
(2) Recommended Test Setup
CAUTIONHigh voltages exist on this EVB. Please handle with care.
Dont touch EVB when powered.
Voltage Source : 12W 265VRMSAC Source
Multimeters : To measure Output voltage and current
Probe : To measure Input voltage and current (100MHz, 600V or more)
Network Analyzer : To measure Loop response (Gain/Phase measurements)
Output Load : LED 9 pieces in series (Vf=3.2V at 350mA/LED)
4. Setup4. Setup
Current
probe
Voltage probe
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED3/ 151) Connect EVB with Test Equipment according to Figure 1.
(Network Analyzer is not required for this procedure.)
2) Set AC Source to 184VRMS.
3) Turn on AC Source. (The LED lights.)
4) Measure Input voltage and current (Input Effective Power),
and measure Output voltage and current (Output Power).
5) Increase AC Source by 5VRMS.
6) Repeat steps 4) and 5) until AC Source reach 265VRMS .
7) Turn off AC Source.
(3) Line Regulation and Effciency Measurement Procedure
Figure 1 Recommended Test Setup
AC Power
Supply
Loop injection points
(TP5 and TP11)
(4)(Reference) TRIAC Dimmer Test Setup
Figure 2 TRIAC Dimmer Test Setup
1) Connect EVB with Test Equipment according to Figure 2.
2) Set AC Source to 230VRMS.
3) Set TRIAC dimmer to maximum output.
(5)(Reference) TRIAC Dimmer Measurement Procedure
TRIAC
dimmer
AC Power
Supply
Current
probe
Voltage probe
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED4/ 15
3) Set TRIAC dimmer to maximum output.
4) Turn on AC Source. (The LED lights.)
5) Measure output current.
6) Slowly slide TRIAC dimmer to minimum output.
7) Observe output current decreases.
5. Performance Data5. Performance Data
55--1 Efficiency1 Efficiency 55--2 Power Factor2 Power Factor
Fig.3-1 Efficiency
LED ; 9 pieces in series
Fig.3-2 Power FactorPower Factor
LED ; 9 pieces in series
60%65%70%75%80%85%90%95%100%
180 190 200 210 220 230 240 250 260 270VIN AC [V]Efficiency
fac=60Hz fac=50Hz0.800.820.840.860.880.900.920.940.960.981.00
180 190 200 210 220 230 240 250 260 270VIN AC [V]Power Factor
fac=60Hz fac=50Hz
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55--3 3 Line RegulationLine RegulationLine RegulationLine RegulationLine RegulationLine RegulationLine RegulationLine Regulation 55--4 Load Regulation4 Load Regulation
Fig.3-3 Line RegulationLine Regulation
LED ; 9 pieces in series
Fig.3-4 Load Regulation
VIN=AC230VRMS
LED ; 6 - 10 pieces in series
300310320330340350360370380390400
180 190 200 210 220 230 240 250 260 270VIN AC [V]ILED [mA]
fac=60Hz fac=50Hz300310320330340350360370380390400
16 18 20 22 24 26 28 30 32VLED [V]ILED [mA]
fac=60Hz fac=50Hz
55--5 Output Ripple5 Output Ripple 55--6 Switching Waveform6 Switching Waveform
VBULK
Vo
ILED
Fig.3-5 Output Ripple
VIN=AC230VRMS, fac=60Hz
LED ; 9 pieces in series
Fig.3-6 Switching WaveformSwitching Waveform
VIN=DC230V
LED ; 9 pieces in series
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55--7 Turn7 Turn--On WaveformOn Waveform
Fig.3-7 TurnTurn--On WaveformOn Waveform
VIN=0V VIN=0V --> AC230V> AC230VRMSRMS(60Hz)(60Hz)(60Hz)(60Hz)(60Hz)(60Hz)(60Hz)(60Hz)
LED ; 9 pieces in series
55--8 8 TurnTurnTurnTurnTurnTurnTurnTurn--------Off WaveformOff WaveformOff WaveformOff WaveformOff WaveformOff WaveformOff WaveformOff Waveform
Fig.3-8 TurnTurn--Off WaveformOff Waveform
VIN=AC230VVIN=AC230VRMSRMS(60Hz) (60Hz) (60Hz) (60Hz) (60Hz) (60Hz) (60Hz) (60Hz) --> 0V> 0V
LED ; 9 pieces in series
ILED
Vo
VDD
VBULK
MB39C601MB39C601--EVBEVB--04 (Top View)04 (Top View)
Figure 4-1 Top Side
6. 6. Evaluation Board LayoutEvaluation Board Layout
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED7/ 15Figure 4-2 Bottom Side
Figure 4-1 Top Side
Board Layout (Top View)
Figure 4-3 Top Side
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED8/ 15
Figure 4-3 Top Side
Figure 4-4 Bottom Side
7. 7. Circuit DiagramCircuit Diagram
T1
12
00
u
1
R1
5
3.0
1
IC4
2
D5
D1
JP2
R8
5.1
1k
D4
0.0
15
u
C1
0
2
R7
1k
JP1
R16
4.4
2k
Q1
R1
93
9.2
2
R2
14
64
k
R9
20
0k
R1
7
71
.5k
2
IC1
R14
10
0k
J2
IC2
R3
0
7.5
k
R2
41
00
k
TP
8
C1
21
u
R2
72
0k
R2
5
51
1k
Q5
2
R2
6
27
4k
C1
32
20
p
D7
R3
11
M
C5
10
uC
61
0u
C7
56
0u
C8 560u R6 0.512
J4
R3
63
.01
k
2
R43
3.0
1k
C15
0.0
1u
2
C2
20
.22
u
R4
12
0kR3
41
M JP5
C2
00
.01
uR
44
23
.7k
R3
56
04
k
C1
90
.01
u
2
R4
22
k
R3
34
9.9
TP
7
TP
11T
P2
TP
5
IC3
C4
2.2
n
12
TP
4
1 2 3 4 5
1 0 9 8 7
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED9/ 15Figure 5 EVB curcuit diagramJ1 J3TP1 TP3F
12
.5A
F2
2.5
A
VA
R1
D2
D6
TP
9
JP4
R2
91
10
k
R2
86
34
k
C1
40
.01
u
TP
10
R4
01
00
kR
37
10
kR
39
40
.2k
R3
83
3.2
k
R4
9o
pen
C2
10
.01
u
C1
01
C1
60
.01
uC
17
0.1
uC
18
10
0u
0.015uC9R
5
1M
R4
75
k
R12
1M
1
1 1
1
D3 Q
6R
32
4.9
9
R1
5
3.0
1
D8
D9
R4
7
R4
6
R4
5 0
1
R4
80
IC
TP
6
MB39C601
4321
OT
M
PC
L
TZ
E
FB
VD
D
VC
G
GN
D
DR
N
5678
0.0
22
u
C3
Jum
per
L2
1
C1
0.2
2u
C2
0.0
22
u
R1
3
51
0
40
mL
1
4 1
3 2
op
en
op
en
op
en
R1
01
10
k
8. 8. Circuit Parts ListCircuit Parts ListNo COMPONENT DESCRIPTION PART No. VENDOR
1 C1 Capacitor, metal poly, 0.22uF, 400VDC ECQ-E4224KF Panasonic
2 C2, C3 Capacitor,polyester film, 22nF, 630V, +/-10%, 0.260 inch x 0.470 inch ECQ-E6223KF Panasonic
3 C4 Capacitor, ceramic, 2.2nF, X1/Y1 radial DE1E3KX222M muRata
4 C5, C6 Capacitor, ceramic, 10uF, 50V, X7R, +/-10%, 1210 GRM32DF51H106ZA01L muRata
5 C7, C8 Capacitor, alumninum electrolytic, 560uF, 50V, +/-20%, 12.5 mm x 25 mm UPW1H561MHD Rubycon/Nichicon
6 C9, C10 Capacitor, ceramic, 0.015uF, 100V, CDG, +/-5%, 1210 CGA6J2C0G2A153J TDK
7 C12 Capacitor, ceramic, 1.0uF, 10V, X7R, +/-10%, 0805 GRM21BR71A105KA01L muRata
8 C13 Capacitor, ceramic, 220pF, 100V, 125deg, +/-5%, 1206 12061A221JAT2A AVX
9 C14, C15, C16, C19, C20, C21 Capacitor, ceramic, 0.01uF, 50V, X7R, +/-10%, 0603 GRM188R71H103KA01D muRata
10 C17 Capacitor, ceramic, 0.1uF, 25V, X7R, +/-10%, 0603 GRM188R71E104KA01D muRata
11 C18 Capacitor, aluminum, 100uF, 25V, +/-20%, 0.200 inch EEU-FC1E101S Panasonic
12 C22 Capacitor, ceramic, 0.22uF, 25V, X7R, +/-10%, 0603 GRM188R71E224KA88D muRata
13 C101 Not Use (Open) - -
14 D1 Diode, utrafast, power rectifier, 2A, 200V, DO-201AD UG2D-E3/54 Vishay
15 D2 Diode, bridge rectifier, 0.5A, 600V, SO-4 MB6S Fairchild
16 D3 Diode, ultra fast rectifier, 1A, 800V, SMA RS1K-13-F Diodes, Inc.
17 D4 Diode, shunt voltage reference, SOT-23 LM4040C50 Texas Instruments
18 D5 Diode, super fast rectifier, 1A, 200V, 0.220 inch x 0.115 inch ES1D Diodes, Inc.
19 D6 Diode, Zener, 18V, 500mW, SOD-123 MMSZ18T1G ON Semiconductor
20 D7 Diode, switching, dual, 200mA, 70V, SOT-23 MMBD6100LT1G On Semiconductor
21 D8 Diode, Schottky, 1A, 30V, SOD-323 SDM100K30 Diodes, Inc
22 D9 Diode, ultra fast, 1A, 200V, SMA CSFA103-G On Semiconductor
23 F1, F2 Fuse, axial, fast acting, 2.5A, 250V, 0.160 inch x 0.400 inch 026302.5MXL Littelfuse Inc
24 L1 Ind common mode choke, 40mH 750311650 Wurth Midcom
25 L2 Jumper, res, 0.0Ohm, 1206 Std Std
26 Q1 Bipolar, NPN, 100V, 1A, SOT-89 FCX493TA Zetex
27 Q5 Bipolar, NPN, 40V, 200mA, 350mW, SOT-23 MMBT3904-TP Micro Commercial Co
28 Q6 MOSFET, N-channel, 650V, 7.3A, 0.6W, TO-220 FDPF10N60NZ Fairchild
29 R4 Resistor, chip, 75.0kOhm, 1/4W, +/-1%, 1206 RK73B2BTBK753G KOA
30 R5, R12 Resistor, chip, 1.00MOhm, 1/4W, +/-1%, 1206 ERJ-8ENF1004V Panasonic
31 R6 Resistor, chip, 0.51Ohm, 1/2W, +/-1%, 2010 MCR50JZHFLR510 Rohm Semiconductor
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED10/ 15
31 R6 Resistor, chip, 0.51Ohm, 1/2W, +/-1%, 2010 MCR50JZHFLR510 Rohm Semiconductor
32 R7 Resistor, chip, 1.00kOhm, 1/4W, +/-1%, 1206 RK73B2BTBK102J KOA
33 R8 Resistor, metal flm, 5.11kOhm, 1/2W, +/-1% SFR16S0005111FR500 Vishay/BC Components
34 R9 Resistor, chip, 200kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF2003V Panasonic
35 R13 Resistor, carbon flm, 510Ohm, 1/2W, +/-5%, RN55 CFS1/2CT26A511J KOA
36 R14, R24, R40 Resistor, chip, 100kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF1003V Panasonic
37 R15 Resistor, chip, 3.01Ohm, 1/8W, +/-1%, 0805 RC0805FR-073R01L Yageo
38 R16 Resistor, chip, 4.42kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF4421V Panasonic
39 R17 Resistor, chip, 71.5kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF7152V Panasonic
40 R19 Resistor, chip, 39.2Ohm, 1/8W, +/-1%, 0805 RMCF0805FT39R2 Stackpole Electronics Inc
41 R21 Resistor, chip, 464kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF4643V Panasonic
42 R25 Resistor, chip, 511kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF5113V Panasonic
43 R26 Resistor, chip, 274kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF2743V Panasonic
44 R27, R41 Resistor, chip, 20.0kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF2002V Panasonic
45 R28 Resistor, chip, 634kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF6343V Panasonic
46 R29 Resistor, chip, 110kOhm, 1/8W, +/-1%, 0805 RK73B2ATBK114G KOA
47 R30 Resistor, chip, 7.5kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF7501V Panasonic
48 R31 Resistor, chip, 1.00MOhm, 1/8W, +/-1%, 0805 ERJ-6ENF1004V Panasonic
49 R32 Resistor, chip, 4.99Ohm, 1/10W, +/-1%, 0603 RC0603FR-074R99L Yageo
50 R33 Resistor, chip, 49.9Ohm, 1/10W, +/-1%, 0603 ERJ-3EKF49R9V Panasonic
51 R34 Resistor, chip, 1.00MOhm, 1/10W, +/-1%, 0603 ERJ-3EKF1004V Panasonic
52 R35 Resistor, chip, 604kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF6043V Panasonic
53 R36, R43 Resistor, chip, 3.01kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF3011V Panasonic
54 R37 Resistor, carbon flm, 10.0kOhm, 1/2W, +/-5%, RN55 CFS1/2CT26A103J KOA
55 R38 Resistor, chip, 33.2kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF3322V Panasonic
56 R39 Resistor, chip, 40.2kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF4022V Panasonic
57 R42 Resistor, chip, 2.00kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF2001V Panasonic
58 R44 Resistor, chip, 23.7kOhm, 1/10W, +/-1%, 0603 ERJ-3EKF2372V Panasonic
59 R45 Jumper, res, 0.0Ohm, 0603 Std Std
60 R46 Not Use (Open) - -
61 R47 Not Use (Open) - -
62 R48 Jumper, res, 0.0Ohm, 0603 Std Std
63 R49 Not Use (Open) - -
64 R101 Resistor, chip, 10.0kOhm, 1/16W, +/-0.5%, 0603 RR0816P-103-D Susumu
65 T1 Transformer, 1200uH, +/-10%, 0.567 inch x 0.876 inch 750811145 Wurth Midcom
66 IC Driver IC for LED Lighting, SOL8 MB39C601 Fujitsu
67 IC1, IC2, IC3 Op-Amp Low Voltage Rail-to-Rail Output, 130uA typical, SOT-23-5 LMV321IDBV Texas Instruments
68 IC4 Optocoupler, High Isolation Voltage, SOP4 Gull-Wing PS2561L-1-A NEC
69 VAR1 Varistor, disk, 275VAC, 8.5 mm diameter S10K275E2 EPCOS
70 J1, J2, J3, J4 Connector ML-2100-2P SATO parts
Figure 6-1 Top View
9. Evaluation Board Externals9. Evaluation Board Externals
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED11/ 15
Figure 6-2 Bottom View
Figure 6-3 Reference) LED board
10-1 Flyback Method
MB39C601 is a flyback type switching regulator controller, which is dedicated to supply to its
target LED constant. The LED current is regulated by controlling the switching on-time or controlling the switching frequency. The LED current is converted into detecting voltage (Vs) by sense resistance (R6) connected in series with LED. Vs is compared with the reference voltage that sets the LED current to constant value by an external error amplifier (Err AMP). When Vs falls below a reference voltage, Err AMP output rises and the current that flows into the Opto-Coupler is decreased.The configuration of MB39C601-EVB-04 is on-time control.MB39C601 becomes to on-time control by connecting the collector of the Opto-Coupler from
OTM pin through resistance. In on-time control, it controls on-time at OTM pin current. So, on-time increases when the current of OTM pin decreases. And the average current supplied to LED is regulated, because on-time is regulated at the constant switching frequency.By the way, MB39C601 becomes to switching frequency control by connecting the emitter of
the Opto-Coupler from FB pin through resistance. In switching frequency control, it controls switching frequency at FB pin current. So, switching frequency becomes high when the current of FB pin decreases. And the average current supplied to LED is regulated, because switching frequency is regulated at the constant on-time.
10. Reference10. Reference
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T1
IC4
2
D1
R85.11k
D4
0.015uC10
2
J2
C510u
C610u
C7560u
C8
560u
R6
0.51
2
J4
R363.01k
2
R433.01k
C150.01u
2
C220.22u
R4120k
R341M
JP5
C200.01u
R4423.7k
R35604k
C190.01u
2
R422k
R3349.9
IC3
1
2
3
4
5
10
9
8
7
VCOMMAND
LED Load
Vs
R40100k
R3710k
C210.01u
1
IC
MB
39
C6
01
4
3
2
1
OTM
PCL
TZE
FB VDD
VCG
GND
DRN
5
6
7
8
1
1
10-2 Cascode Switching
The switch in Primary Winding is a cascode connection.The gate of external MOSFET is
connected with VCG pin, and the source is connected with the drain of internal Driver MOSFET. When the swich is on-state, internal Driver MOSFET is turned on, internal HS Driver MOSFET is turned off, and the source voltage of external MOSFET becomes to GND. For this period the DC bias is supplied to the gate of external MOSFET from VCG pin. Therefore external MOSFET is turned on.When the switch is off-state, internal Driver MOSFET is turned off, HS Driver MOSFET is
turned on, and the source voltage of external MOSFET becomes to VCG voltage. For this period the DC bias is supplied to the gate of external MOSFET from VCG pin. Therefore external MOSFET is turned off. Moreover, the current flowing into internal Driver MOSFET is equal to the current of Primary Winding. Therefore, the peak current into Primary Winding can be detected without the sense resistance.
D2
0.015u
C9R5
1M
R4
75k
R12
1M
D3
T1
Q6R324.99
1
R15
3.01
0.022u
C3
JumperL2
1
1
2
3
4
5
0
9
8
7
VBULK
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED13/ 15
10-3 Natural PFC (Power Factor Control) Function
In the AC voltage input, when the input current waveform is brought close to the sine-wave,
and the phase difference is brought close to Zero, Power Factor is improved. In the flyback method operating in discontinuous conduction mode, when the input capacitance is set small, the input current almost becomes equal with peak current of Primary Winding.
VBULK : Supply voltage of Primary WindingLMP : Inductance of Primary WindingtON : On-time
In on-time control, if loop response of ErrAMP is set to lower than the AC frequency (1/10 of the AC frequency), on-time becomes to constant. Therefore, input current is proportional to input voltage, so Power Factor is regulated.
=
=
ON
MP
BULK
MP
BULK
PEAK
t
L
V
L
VI
ONt
C160.01u
C170.1u
C18100u
1
D8
D9
IC
MB
39
C6
01
4
3
2
1
OTM
PCL
TZE
FB VDD
VCG
GND
DRN
5
6
7
8
R10110k
10-4 Dimmer Phase Angle Detection
2
D5
D1
R85.11k
D4
0.015uC10
2
IC2
R307.5k
R24100k
C121u
R2720k
R25511k
Q5
2
R26274k
C13220p
D7
R311M
1
2
3
4
5
10
9
8
7
T1
VCOMMAND
(1) (2)
0V
MB39C601 is compatible with both leading-edge and trailing-edge phase-cut dimmers. (1)
part operates as a comparator, and (2) part operates as a switched capacitor. When the secondary side of the transformer is a positive voltage, the base of Q5 becomes 5V, Q5 is turned on, and C12 is discharged through R27. Moreover, when the secondary side of the transformer is a negative voltage, Q5 is turned off and C12 is charged through R27. The average input voltage increases and decreases depending on the dimmer angle. Therefore the voltage depending on the phase angle is maintained by C12. The voltage maintained by C12 is amplified by OP_AMP(IC2), and the output voltage of OP_AMP is supplied as VCOMMAND. VCOMMAND falls when the phase angle is high, VCOMMAND rises when the phase angle is low.
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED14/ 15
2
The reference voltage of Err_AMP is generated by dividing VCOMMAND with R35 and R44.
Thus, the LED current is regulated depending on the phase angle.
10-5 TRIAC Holding Current
ILEDAUGMENTDimmer Conduction Angle100% 0%0mA
350mLED CurrentT1
2
D1
R85.11k
D4
0.015uC10
2
R71k
R164.42k
Q1
R1939.2
2
R21464k
R9200k
R1771.5k
2
IC1
R14100k
1
2
3
4
5
10
9
8
7
R60.51
2
VCOMMAND
IMETER
LED Load
ILED IAUGMENT
At the TRIAC dimmer, the holding current is necessary to maintain on-state of TRIAC. When
the holding current is not maintained, TRIAC is turned off. Because power consumption of the LED lighting is lower than the light bulbs, it becomes impossible to maintain the holding current of TRIAC at a light load. When the TRIAC phase angle is high and the LED current decreases, the load becomes light. In this case, the flicker might be generated because the TRIAC dimmer is irregularly turned off. Then, to maintain the holding current of TRIAC, the load current is added. This load current circuit is added to the secondary side as shown in the following. When VCOMMAND decreases more than the voltage set with R17 and R9, Q1 is turned on and the load current is added through R7.
Fujitsu semiconductor limited Confidential Copyright 2012 FUJITSU SEMICONDUCTOR LIMITED15/ 15
All Rights Reserved.
The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales
representatives before ordering.
The information and circuit diagrams in this document are presented as examples of semiconductor device applications, and are not
intended to be incorporated in devices for actual use.
Also, FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use
of this information or circuit diagrams.
FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and other office equipment,
industrial, communications, and measurement equipment, personal or household devices, etc.).
CAUTION:
Customers considering the use of our products in special applications where failure or abnormal operation may directly affect human
lives or cause physical injury or property damage, or where extremely high levels of reliability are demanded (such as aerospace systems,
atomic energy controls, sea floor repeaters, vehicle operating controls, medical devices for life support, etc.) are requested to consult with
FUJITSU sales representatives before such use. The company will not be responsible for damages arising from such use without prior
approval.
Any semiconductor devices have an inherent chance of failure. You must protect against injury, damage or loss from such failures by
incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of over-current
levels and other abnormal operating conditions.
If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign
Exchange and Foreign Trade Law of Japan, the prior authorization by Japanese government will be required for export of those products
from Japan.
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