Many FPGAs, ASICs and microprocessors require tight accuracy and complex sequencing of their power supplies for high reliability and to prevent processor damage. The LTC®2937 is designed to carefully control and supervise these point-of-load supplies, while providing flexibility to reconfigure on the fly—effectively future proofing the design. A unique and flexible sequencing technique turns supplies on and off in any one of 1023 possible sequence positions, separated either with adjustable time delays or by qualifying events. Digitally adjustable ±0.75% accurate undervoltage (UV) and overvoltage (OV) thresholds reduce development time, improve system reliability, and ease resulting power supply tolerances. A simple single wire connection synchronizes up to fifty LTC2937s for sequencing expansion to 300 supplies, simplifying board routing. The LTC2937, along with the LTC2933 and LTC2936 programmable 6-channel voltage supervisors, is supported by an interactive and intuitive GUI for configuration, system diagnostics and debugging.
Features n Time and Event Based Sequencing for 6 Power Supplies n 12 Programmable UV and OV Comparators with ±0.75% Guaranteed Accuracy Over Temperature
n I2C/SMBus Adjustable 8-Bit UV and OV Thresholds n EEPROM for Storing Configuration and Fault Log n Single Wire Synchronizes up to 50 Devices and 300 Supplies n Supported by LTpowerPlay® GUI n No Software Coding Required for Autonomous Operation n Breakpoints and Sequence Stepping n Programmable Reset Output Delay n Wide Supply Range: 2.9V to 16.5V n 28-Pin 5mm x 6mm QFN Package
Eases Sequencing and Voltage Supervision of FPGA/ASIC/µProcessor Supplies
Programmable Six Supply Sequencer and Supervisor
LTC2937
SEQUENCER
EEPROM
UV/OV THRESHOLDS
STATUS OK
FAULT LOGGING
2.5V
ENABLE 6x
1.5V
1.2V
1.8V
3.3V
5V
I2C/SMBus
MARGIN
RESET
ON
SystemLogic
DC/DC Converters
5V
3.3V
2.5V
1.8V
1.5V
1.2V
ON
VOLTAG
E
V1V2V3V4
V5
V6
TIME
Sequenced Power Supply Waveforms
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LTpowerPlay Development Environment
Programmable 6-Channel Sequencer and Supervisors with EEPROM
Programmable Time and Event Based Sequencing Example
LLTC2937
2.9V TO 16.5V
FAULTB
RSTB
VPWR
GND
EN1
EN2
EN3
EN4
EN5
EN6
V1
V2
V3
V4
V5
V6
VCORE1
VIO1
READY
SYSTEM 1µP/FPGA
VCORE2
VIO2
VAUXSYSTEM 2µP/FPGA
ON
SDA
SCL
SPCLK
n System 1: Core and I/O supplies separated with time delay (t1)
n System 2 supplies wait for READY signal from System 1 to cross V3 threshold (event based delay t2)
n System 2: Core, I/O and Aux supplies separated with time delays
n Sequence position clock (SPCLK) connects to other LTC2937s for expansion
Device Sequencer Comparator Outputs
Threshold Range
Threshold Accuracy Power Supply Package
(mm × mm) Demo Board*
LTC2933 No No 1V to 13.9V (1×)0.2V to 5.8V (5×) ±1% 3.4V to 13.9V 5×4 DFN-16,
SSOP-16 DC1633
LTC2936 No Yes 0.2V to 5.8V (6×) ±1% 3.13V to 13.9V 4×5 QFN-24, SSOP-24 DC1605
LTC2937 Yes No 0.2V to 6V (6×) ±0.75% 2.9V to 16.5V 5×6 QFN-28 DC2313
* DC1613 I2C-USB adapter connects demo board to computer running LTpowerPlay
VCORE1
VIO1READY
VCORE2VIO2
VAUX
SYSTEM 2 DOES NOT SEQUENCE UNTIL SYSTEM 1 IS READY
t1 t2TIME
DELAYEVENT DELAY
0815
www.linear.com/2937 n 1-800-4-LINEAR