ISL9444

4

FN7665.0

May 23, 2011

24

ISEN3

Current signal input for PWM3. This pin is used to monitor the voltage drop across the lower MOSFET for current loop

feedback and overcurrent protection.

25

PHASE3

Phase node connection for PWM3. This pin is connected to the junction of the upper MOSFET’s source, output filter inductor,

and lower MOSFET’s drain. PHASE3 is the internal lower supply rail for the UGATE3.

26

BOOT3

Bootstrap pin to provide bias for PWM3 high-side driver. The positive terminal of the bootstrap capacitor connects to this

pin. The bootstrap diodes are integrated to help reduce total cost and reduce layout complexity.

27

UGATE3

High-side MOSFET gate driver output for PWM3.

28

LGATE3

Low-side MOSFET gate driver output for PWM3.

29

PGND

Power ground connection for all three PWM channels. This pin should be connected to the sources of the lower MOSFETs

and the (-) terminals of the external input capacitors

30

CLKOUT

Clock signal output. The frequency of the clock signal is two times of the ISL9444 switching frequency set by the resistor

from RT to ground.

31

ISEN2

Current signal input for PWM2. This pin is used to monitor the voltage drop across the lower MOSFET for current loop

feedback and overcurrent protection.

32

PHASE2

Phase node connection for PWM2. This pin is connected to the junction of the upper MOSFET’s source, output filter inductor,

and lower MOSFET’s drain. PHASE2 is the internal lower supply rail for the UGATE2.

33

BOOT2

Bootstrap pin to provide bias for PWM2 high-side driver. The positive terminal of the bootstrap capacitor connects to this

pin. The bootstrap diodes are integrated to help reduce total cost and reduce layout complexity.

34

UGATE2

High-side MOSFET gate driver output for PWM2.

35

LGATE2

Low-side MOSFET gate driver output for PWM2.

36

LGATE1

Low-side MOSFET gate driver output for PWM1.

37

UGATE1

High-side MOSFET gate driver output for PWM1.

38

BOOT1

Bootstrap pin to provide bias for PWM1 high-side driver. The positive terminal of the bootstrap capacitor connects to this

pin. The bootstrap diodes are integrated to help reduce total cost and reduce layout complexity.

39

PHASE1

Phase node connection for PWM1. This pin is connected to the junction of the upper MOSFET’s source, output filter inductor,

and lower MOSFET’s drain. PHASE1 is the internal lower supply rail for the UGATE1.

40

ISEN1

Current signal input for PWM1. This pin is used to monitor the voltage drop across the lower MOSFET for current loop

feedback and overcurrent protection.

-

EPAD

EPAD at ground potential. Solder it directly to GND plane for better thermal performance.

PIN

NAME

FUNCTION