DC2419A Analog Devices

LTC3372 60V Low I Buck Controller Q Plus 4-Channel 8A Configurable Buck DC/DCs FEATURES DESCRIPTION n HV Buck Controller: V = 4.5V to 60V, V = 5V/3.3V The LTC 3372 is a highly flexible multioutput power supply IN OUT n LV Buck Regulators: V = 2.25V to 5.5V, IC. The device includes a high-performance, high voltage INA-H V 0.8V (HV) step-down DC/DC switching regulator controller that OUT1-4 n 81A LV Buck Integrated Power Stages, Configurable drives an all N-channel synchronous power FET stage as2, 3 or 4 Output Channels from a 4.5V to 60V input. n 8 Unique Output Configurations (1A to 4A Per Channel) The LTC3372 also includes four low voltage (LV) synchro- n Low Total No-Load Input Supply Current (I ) Q nous buck regulators that can be programmed by the n 15A HV Controller Only (5V ) OUT C1-C3 pins to share eight 1A integrated power stages in n 23A HV Controller Only (3.3V ) OUT one of eight possible configurations. Each power stage is n 33A HV Controller (3.3V ) Plus One LV Regulator OUT powered from independent inputs which may be connected n 9A Per Additional LV Regulator Channel to the HV bucks V or to other 2.25V to 5.5V supplies. OUT n 1MHz to 3MHz Operation (HV Runs at 1/6 Frequency) n The CT pin programs timing parameters of the watchdog Programmable or Synchronizable to External Clock n timer and LV outputs Power-On Reset (RST). Precision Programmable Watchdog and Power-On Reset Delay n enable thresholds facilitate reliable power-up sequencing. IC Die Temperature Monitor Output n Thermally Enhanced 48-Pin 7mm 7mm QFN Package The LTC3372 is available in a 48-pin 7mm 7mm QFNpackage. APPLICATIONS All registered trademarks and trademarks are the property of their respective owners. n Automotive and Industrial Always-On Systems n General Purpose Multi-Channel Power Supplies LV Efficiency vs Output Current TYPICAL APPLICATION 100 V IN 90 60V MAX 47F 4.5V MIN 80 V INTV 2 IN CC 4.7F RUN 70 100k INTV PGOOD CC TG 60 0.1F INTV /GND V CC OUTPRG V 50 2.2H OUT 5m BOOST 3.3V/5V 2.2nF 40 8.06k 3A* SW ITH 150F LTC3372 47F 30 100pF BG 2 1A Buck 0.01F 20 V = 3.3V INAH 2A Buck V = 1.8V OUT 3A Buck TRACK/SS 10 + SENSE f = 2MHz SW 4A Buck GND SENSE 0 V /EXTV 0.0001 0.001 0.01 0.1 1 4 OUT CC V V V V OUT INA INH OUT OUTPUT CURRENT (A) 3372 TA01b V V V OUT1 INB ING V OUT4 SWA SWH 1.0V 2.5V SWB SWG 2A 2A Low Voltage Buck Regulator Configurations FB1 FB4 EN1 EN4 C3 C2 C1 BUCK1 BUCK2 BUCK3 BUCK4 V V V V OUT INC INF OUT 0 0 0 2A 2A 2A 2A V V V IND INE V OUT2 OUT3 SWC SWF 1.2V 1.8V 0 0 1 3A 1A 2A 2A SWD SWE 2A 2A 0 1 0 3A 1A 1A 3A FB2 FB3 EN3 0 1 1 4A 1A 1A 2A EN2 TEMP PLLIN/MODE WDI 1 0 0 3A 2A 3A WDO RT 1 0 1 4A 2A 2A 100k CT RSTB INTV CC C1 C2 C3 1 1 0 4A 1A 3A *FULL LOAD IS EQUIVALENT TO SPECIFIED LOAD CURRENT 3372 TA01a 1 1 1 4A 4A PLUS THE FULL LOAD INPUT CURRENT FROM V OUT1-4 Rev. A 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC3372 TABLE OF CONTENTS Features ............................................................................................................................ 1 Applications ....................................................................................................................... 1 Typical Application ............................................................................................................... 1 Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Order Information ................................................................................................................. 4 Electrical Characteristics ........................................................................................................ 4 Typical Performance Characteristics .......................................................................................... 8 Pin Functions .....................................................................................................................14 Block Diagram ....................................................................................................................17 Operation..........................................................................................................................18 Low Voltage Regulators ........................................................................................................................................ 20 Applications Information .......................................................................................................23 High Voltage Buck Controller ................................................................................................................................ 23 Low Voltage Buck Regulators ............................................................................................................................... 33 Printed Circuit Board PCB Layout Considerations ................................................................................................. 35 Typical Applications .............................................................................................................37 Package Description ............................................................................................................42 Revision History .................................................................................................................43 Typical Application ..............................................................................................................44 Related Parts .....................................................................................................................44 Rev. A 2 For more information www.analog.com