LTM4638

9

Rev. C

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BLOCK DIAGRAM

DECOUPLING REQUIREMENTS

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

CIN

External Input Capacitor Requirement

(VIN = 3.1V to 20V, VOUT = 1.5V)

IOUT = 15A

22

44

µF

COUT

External Output Capacitor Requirement

(VIN = 3.1V to 20V, VOUT = 1.5V)

IOUT = 15A

220*

470*

µF

*Additional capacitance may be required under extreme temperature and/or capacitor bias voltage conditions due to variation of actual capacitance over bias voltage and temperature.

Figure 1. Simplified LTM4638 Block Diagram

POWER CONTROL

2.2µF

0.1µF

0.1µF

CIN

22µF

25V

INTVCC

TRACK/SS

RUN

VIN

MODE/CLKIN

CLKOUT

PHMODE

COMPa

COMPb

1µF

VOUT

VOSNS–

VOSNS+

FB

VIN

10k

PGOOD

VOUT

1.5V

15A

RFB

40.2k

60.4k

VIN

3.1V TO 20V

INTVCC

GND

0.24µH

4638 BD

FREQ

274k

INTERNAL

COMP

GND

INTERNAL

FILTER

COUT

100µF

×3

6.3V

+

–

DIFF

AMP

TSENSE–

TSENSE+