NCP81174

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5

PIN DESCRIPTION

Pin

Name

Description

1

VIDBUF

VID PWM pulse output from an internal buffer.

2

VID

Voltage ID from processor.

3

VR_RDY

Power good indicator.

4

EN

Chip enable.

5

PSI

Power saving control. Three levels.

6

12VMON

than 4 V at all time.

7

ROSC

A resistance from this pin to ground programs the oscillator frequency.

8

ILIM

Over current shutdown threshold setting.

9

VSP

Non−inverting input to the internal differential remote sense amplifier.

10

VSN

Inverting input to the internal differential remote sense amplifier.

11

DIFFOUT

Output of the differential remote voltage sense amplifier.

12

COMP

Output of the compensation amplifier.

13

VFB

Inverting input of the compensation error amplifier

14

VDRP

Voltage signal proportional to the total current.

15

VDFB

Current summing amplifier inverting input

16

CSSUM

Current summing output signal

17

CS1N

Inverting input to current sense amplifier, phase 1.

18

CS1

Non−inverting input to current sense amplifier, phase 1.

19

CS2N

Inverting input to current sense amplifier, phase 2.

20

CS2

Non−inverting input to current sense amplifier, phase 2.

21

CS3N

Inverting input to current sense amplifier, phase 3.

22

CS3

Non−inverting input to current sense amplifier, phase 3.

23

CS4N

Inverting input to current sense amplifier, phase 4.

24

CS4

Non−inverting input to current sense amplifier, phase 4.

25

G1

Phase 1 PWM output, 3 levels.

26

G2

Phase 2 PWM output, 3 levels.

27

G3

Phase 3 PWM output, 3 levels.

28

G4

Phase 4 PWM output, 3 levels.

29

DRVON

Gate driver enable.

30

VCC

Power supply for the chip. NCP81174 has a built−in 5 V shunt regulator, allowing it to connect to the external

12 V supply through a resistor. Do not connect a 5 V supply to VCC directly.

31

VREF

2.0 V output reference voltage. A 10 nF ceramic capacitor is recommended to connect this pin to ground.

32

REFIN

Reference voltage input for output voltage regulation.

33

FLAG

Thermal pad and analog ground, connected to system ground.