DC2347A

LTC2937 Programmable Six Channel Sequencer and Voltage Supervisor with EEPROM FEATURES DESCRIPTION n Time and Event Based Sequencing The LTC 2937 is a 6-channel power supply sequencer n 12 Programmable Undervoltage (UV) and Overvolt- and voltage supervisor. Supplies are enabled or disabled age (OV) Comparators: 0.75% Accuracy with precise user controlled order and time spacing. To 2 n I C/SMBus Interface detect power supply output faults during sequencing and n Stalled Power Supply Detection monitoring, the LTC2937 accurately monitors supply n Single Wire Synchronization Allows Controller turn-on/-off delays and output voltage levels. In the event Expansion to 50 Devices (300 Power Supplies) of a fault, response actions include complete power supply n Configuration and Fault Logging in EEPROM shutdown and optional restarts. Root cause of power n EEPROM Specified Over Entire Temperature Range, faults are logged to EEPROM. For systems with high Rated to 125C, 10k Writes, 20yr Retention supply count, a simple single wire connection between n Supported by LTpowerPlay GUI multiple LTC2937 devices allows sequencing expansion n Fault and System Status Registers to 300 supplies. After successful sequencing and supply n Reset Output with Programmable Delay voltage stabilization, the reset output pulls high to initiate n Wide Input Supply Voltage Range: 2.9V to 16.5V microprocessor or other system activity. To accommodate n 28-Lead QFN (5mm 6mm) Package supply margin testing, the reset output can be disabled. Upon supply turn-off, integrated current sources are available as needed to discharge slowly decaying supplies. APPLICATIONS Configuration EEPROM supports autonomous operation without software. n Network Servers All registered trademarks and trademarks are the property of their respective owners. Protected n Data Storage Systems by U.S. Patents including 8627132. n Telecom Equipment n High Availability Computer Systems TYPICAL APPLICATION Six Power Supply Sequencer and Supervisor Sequenced Power Supply Waveforms DC/DC CONVERTERS 5V 12V V IN 3.3V VPWR SDA EN1 RUN1 OUT1 5.0V 2 I C/SMBus SCL EN2 RUN2 OUT2 3.3V 2.5V INTERFACE ALERTB EN3 RUN3 OUT3 2.5V V1 EN4 RUN4 OUT4 1.8V 1.8V LTC2937 V2 ON EN5 RUN5 OUT5 1.5V V3 MARGB 1.5V EN6 RUN6 OUT6 1.2V TO/FROM FAULTB V4 GND OTHER RSTB 1.2V DEVICES V5 SPCLK V1 SHARE CLK V6 ASEL1 V2 R1 ASEL2 V3 ON ASEL3 V4 3.3k WP V5 2937 TAO1b VDD V6 TIME C1 GND 2.2F 2937 TA01a Rev. B 1 Document Feedback For more information www.analog.com VOLTAGELTC2937 TABLE OF CONTENTS Features ..................................................... 1 MONITOR STATUS ................................................34 Applications ................................................ 1 DEVICE ID ..............................................................34 Typical Application ........................................ 1 Applications Information ................................ 35 Description.................................................. 1 Introduction ............................................................35 Absolute Maximum Ratings .............................. 3 Powering the LTC2937 ............................................35 Order Information .......................................... 3 Write Protection ......................................................35 Pin Configuration .......................................... 3 Updating Volatile or Nonvolatile Memory ................35 Electrical Characteristics ................................. 4 Sequence Position Clock (SPCLK) ..........................36 Serial Bus Timing Diagram .............................. 7 System Configuration .............................................37 Sequence-Up Threshold Timing Diagram .............. 7 Sequence-Up and Sequence-Down Control ............37 Sequence-Down Event Based Timing Diagram........ 8 Sequence-Up Parameters .......................................38 Sequence-Down Time Based Timing Diagram ........ 9 Voltage Supervision ................................................38 Typical Performance Characteristics .................. 10 Voltage Monitor Range ...........................................38 Pin Functions .............................................. 12 UV and OV Thresholds ............................................39 Block Diagram ............................................. 13 UV Thresholds and Sequence-Up Hysteresis ..........39 Operation................................................... 14 Selecting Resistors for Adjustable Range ...............39 Slave Addresses ..................................................... 15 OV Thresholds in Adjustable Applications ..............40 2 I C Interface ........................................................... 16 RSTB Response ...................................................... 41 Condensed Command Summary ....................... 17 Sequence-Down Parameters .................................. 41 Command Descriptions .................................. 18 Discharge Thresholds .............................................42 WRITE PROTECTION ............................................. 18 Active Supply Discharge .........................................42 SPECIAL LOT ......................................................... 18 Fault Descriptions ...................................................43 ON OFF CONTROL ................................................. 19 CONTROL Faults .....................................................43 V RANGE ...............................................................20 SEQUENCE Faults ...................................................43 V THRESHOLD n ...................................................21 SUPERVISOR Faults ...............................................43 Voltage Threshold Encoding ...................................21 EXTERNAL Faults ...................................................43 TON TIMERS n ......................................................22 SHARE CLK Faults .................................................43 TOFF TIMERS n .....................................................23 Fault Reporting .......................................................44 SEQ UP POSITION n ............................................ 24 Fault Management ..................................................44 SEQ DOWN POSITION n ......................................25 Fault Debugging Tools ............................................46 RSTB CONFIG ........................................................26 Share Clock (SHARE CLK) .....................................46 FAULT RESPONSE .................................................27 Asynchronous Supply Control ................................46 MONITOR STATUS HISTORY ................................29 LTpowerPlay: An Interactive GUI for Power System CLEAR ALERTB .....................................................30 Management ........................................................... 47 STORE ....................................................................30 External Connection Design Checklist .................... 47 RESTORE ................................................................30 Minimum Connections for Programming ................48 CLEAR ....................................................................30 Interconnect Between Multiple LTC2937s ...............48 STATUS INFORMATION .........................................31 System Event Based Sequencing ............................48 BREAK POINT ........................................................32 Package Description ..................................... 50 SEQ POSITION COUNT .........................................32 Revision History .......................................... 51 MONITOR BACKUP ................................................33 Typical Application ....................................... 52 Related Parts .............................................. 52 Rev. B 2 For more information www.analog.com