LTC2928 Multichannel Power Supply Sequencer and Supervisor Fea T Descrip T n Easily Configure Power Management The LTC 2928 is a four channel cascadable power without Software supply sequencer and high accuracy supervisor. Sequenc- n Controls Up to Four Supplies per Device ing thresholds, order and timing are configured with just a n Cascades for Additional Supplies few external components, negating the need for PC board n layout or software changes during system development. Staged Supply Sequencing with Multiple LTC2928s may be easily connected to sequence Adjustable Time Positions n an unlimited number of power supplies. Fault Event Reporting with Diagnostics n Selectable System Shutdown on Fault Sequence outputs control supply enable pins or n 1.5% Undervoltage Monitor Accuracy N-channel pass gates. Precision input comparators with n Overvoltage and/or Fault Indication individual outputs monitor power supply voltages to 1.5% n Configurable Undervoltage and accuracy. Supervisory functions include undervoltage Overvoltage Thresholds and overvoltage monitoring and reporting as well as P n Charge Pumped Enable Pins Drive N-Channel MOS- reset generation. RST may be forced high to complement FETs margin testing. n Operates from 2.9V to 16.5V Application faults, whether internally or externally gener- n 5mm 7mm 38-lead QFN and ated, can shut down all controlled supplies. The type and 36-lead SSOP Packages source of faults are reported for diagnosis. Individual channel controls are available to independently exercise a T enable outputs and supervisory functions. n Network/Telecom Infrastructure n A high voltage input allows the LTC2928 to be powered Sequencing for Multiple I/O and Core Voltages n from voltages as high as 16.5V. A buffered reference Power Management output permits single negative power supply sequencing L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. and monitoring operations. Protected by U.S. Patents, including 4843302, 6949965. Typical a T Sequencing Up and Down LTM4600 3.3V 12V V V IN OUT RUN 3.3V LTC3414 10k V V 1.2V IN OUT 2.5V RUN 1.8V LTC1628 1.2V 2.5V V V IN OUT RUN AUSTIN LYNX Si7894ADP 1V/DIV V V IN OUT 1.8V ON AXA010AY93 100 12.1k 36.5k 0.1F 23.2k 51.1k HV EN2 EN1 EN4 EN3 CC ON ON V1 95.3k RT1 V2 24.3k DONE RT2 V3 9.53k LTC2928 RT3 V4 SYSTEM 1.5k RT4 RST RESET 3.4k DONE OV START SEQUENCE V FLT FAULT CC SEQUENCE DOWN SEQUENCE UP START GND MS1 VSEL RTMR PTMR STMR 1F UP COMPLETE 10k 10k 10k 10k COMPLETE SEQUENCE 0.047F 3300pF DOWN 2928 TA07 ALL RESISTORS 1% 2928 TA06 2928fa 1 For more information www.linear.com/LTC2928 ion pplica ions pplica ion uresLTC2928 a Te Maxi Mu M r a T (Note 1) Supply Voltages FLT, RST, OV, CAS ................................ 0.3V to 6.5V HV ...................................................... 0.3V to 18V DONE, REF ...................................0.3V to V + 0.3V CC CC V ........................................................ 0.3V to 6.5V RMS Currents CC Input Voltages IV ................................................................. 10mA CC V1, V2, V3, V4 .........................................0.3V to 12V IHV .............................................................. 20mA CC MS1, MS2, RDIS ................................... 0.3V to 6.5V I .................................................................. 10mA REF SQT1, SQT2, VSEL ............................... 0.3V to 6.5V Operating Ambient Temperature Range RT1, RT2, RT3, RT4 .............................. 0.3V to 6.5V LTC2928C ................................................ 0C to 70C ON, OVA .........................................0.3 to V + 0.3V LTC2928I .............................................40C to 85C CC STMR, PTMR, RTMR .....................0.3 to V + 0.3V Storage Temperature Range CC Output Voltages SSOP Package ................................... 65C to 150C EN1, EN2, EN3, EN4 (Note 3) ..................0.3V to 12V QFN Package ..................................... 65C to 150C CMP1, CMP2, CMP3, CMP4.................. 0.3V to 6.5V Lead Temperature (Soldering, 10 sec) SSOP Package ..................................................300C p in c F T TOP VIEW TOP VIEW 1 36 CMP4 CMP1 2 35 CMP3 CMP2 3 34 V3 EN2 38 37 36 35 34 33 32 4 33 EN3 V2 OVA 1 31 EN3 5 32 V4 OVA EN1 2 30 V4 6 31 EN4 V1 3 29 EN4 EN1 N/C RTMR 7 30 RTMR 4 28 V1 REF 5 27 PTMR 8 29 PTMR REF RT1 6 26 STMR 9 28 STMR RT1 39 RT2 7 25 VSEL 10 27 VSEL RT2 RT3 8 24 GND 11 26 GND RT3 RT4 9 23 HV CC 12 25 HV RT4 CC 22 SQT1 10 V CC 13 24 V SQT1 CC SQT2 11 21 RST 14 23 RST SQT2 MS1 12 20 OV 15 22 OV MS1 13 14 15 16 17 18 19 16 21 FLT MS2 17 20 DONE RDIS UHF PACKAGE 18 19 ON CAS 38-LEAD (5mm 7mm) PLASTIC QFN G PACKAGE 36-LEAD PLASTIC SSOP T = 125C, = 34C/W JMAX JA T = 125C, = 95C/W JMAX JA EXPOSED PAD (PIN 39) PCB GND CONNECTION OPTIONAL 2928fa 2 For more information www.linear.com/LTC2928 MS2 V2 RDIS EN2 CAS CMP2 CMP1 ON N/C CMP4 DONE CMP3 FLT V3 ion igura on ings bsolu