Datasheet LTC3372 (Analog Devices)

LTC3372 60V Low IQ Buck Controller Plus 4-Channel 8A Configurable Buck DC/DCs
FEATURES DESCRIPTION
n
HV Buck Controller: VIN = 4.5V to 60V, VOUT = 5V/3.3V
The LTC®3372 is a highly flexible multioutput power supply n
LV Buck Regulators: VINA-H = 2.25V to 5.5V,
IC. The device includes a high-performance, high voltage
VOUT1-4 ≥ 0.8V
(HV) step-down DC/DC switching regulator controller that n
8×1A LV Buck Integrated Power Stages, Configurable
drives an all N-channel synchronous power FET stage
as 2, 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 (IQ)
nous buck regulators that can be programmed by the n
15µA HV Controller Only (5VOUT)
C1-C3 pins to share eight 1A integrated power stages in n
23μA HV Controller Only (3.3VOUT)
one of eight possible configurations. Each power stage is n
33μA HV Controller (3.3VOUT) Plus One LV Regulator
powered from independent inputs which may be connected n
9μA Per Additional LV Regulator Channel
to the HV buck’s VOUT or to other 2.25V to 5.5V supplies. n 1MHz to 3MHz Operation (HV Runs at 1/6 Frequency) n Programmable or Synchronizable to External Clock The CT pin programs timing parameters of the watchdog n Programmable Watchdog and Power-On Reset Delay timer and LV outputs’ Power-On Reset (RST). Precision n IC Die Temperature Monitor Output enable thresholds facilitate reliable power-up sequencing. n Thermally Enhanced 48-Pin 7mm × 7mm QFN Package The LTC3372 is available in a 48-pin 7mm × 7mm QFN package.
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
TYPICAL APPLICATION LV Efficiency vs Output Current
100 VIN 90 60V MAX 47µF 4.5V MIN V INTV 80 ×2 IN CC 4.7µF RUN 70 100k INTVCC PGOOD TG 60 0.1µF INTVCC /GND VOUTPRG 2.2µH VOUT 50 BOOST 5mΩ 2.2nF 3.3V/5V 8.06k 40 SW 3A* ITH EFFICIENCY (%) 150µF 100pF LTC3372 30 BG ×2 47µF 1A Buck 0.01µF 20 VINA–H = 3.3V 2A Buck V TRACK/SS OUT = 1.8V 10 3A Buck SENSE+ fSW = 2MHz 4A Buck GND SENSE– 0 VOUT/EXTVCC 0.0001 0.001 0.01 0.1 1 4 VOUT VINA VINH VOUT OUTPUT CURRENT (A) V V 3372 TA01b VOUT1 INB ING VOUT4 1.0V SWA SWH 2.5V 2A SWB SWG 2A
Low Voltage Buck Regulator Configurations
FB1 FB4 EN1 EN4
C3 C2 C1 BUCK1 BUCK2 BUCK3 BUCK4
VOUT VINC VINF VOUT 0 0 0 2A 2A 2A 2A V V V OUT2 IND INE VOUT3 1.2V SWC SWF 1.8V 0 0 1 3A 1A 2A 2A 2A SWD SWE 2A 0 1 0 3A 1A 1A 3A FB2 FB3 EN2 EN3 0 1 1 4A 1A 1A 2A TEMP PLLIN/MODE WDI 1 0 0 3A 2A – 3A RT WDO 100k 1 0 1 4A – 2A 2A CT RSTB INTVCC C1 C2 C3 1 1 0 4A – 1A 3A *FULL LOAD IS EQUIVALENT TO SPECIFIED LOAD CURRENT 3372 TA01a PLUS THE FULL LOAD INPUT CURRENT FROM VOUT1-4 1 1 1 4A – – 4A Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Low Voltage Regulators Applications Information High Voltage Buck Controller Low Voltage Buck Regulators Printed Circuit Board PCB Layout Considerations Typical Applications Package Description Revision History Typical Application Related Parts