ISL6265C

FN6976 Rev 2.00

Page 5 of 27

January 11, 2013

36

BOOT_NB

This pin is the upper gate drive supply voltage for the Northbridge controller. Connect an appropriately

sized ceramic bootstrap capacitor between the BOOT_NB and PHASE_NB pins. An internal bootstrap

diode connected to the PVCC pin provides the necessary bootstrap charge.

37

UGATE_NB

Upper MOSFET gate signal from Northbridge controller.

38

PHASE_NB

Switch node of the Northbridge controller. This pin should connect to the source of the Northbridge

channel upper MOSFET(s).

39

LGATE_NB

Lower MOSFET gate signal from Northbridge controller.

40

PGND_NB

The return path of the Northbridge controller lower gate driver. Connect this pin to the source of the lower

MOSFET(s).

41

OCSET_NB

Overcurrent protection selection input for the Northbridge controller. A resistor from this pin to

PHASE_NB sets the OC trip point.

43, 42

VSEN_NB, RTN_NB

Remote Northbridge voltage sense input and return. Connect isolated traces from these pins to the

Northbridge sense points of the processor.

44

FSET_NB

A resistor from this pin to GND programs the switching frequency of the Northbridge controller (for

example, 22.1k ~ 260kHz).

45

COMP_NB

This pin is the output of the Northbridge controller error amplifier.

46

FB_NB

This pin is the output voltage feedback to the inverting input of the Northbridge controller error amplifier.

47

VCC

The bias supply for the IC’s control circuitry. Connect this pin to a +5V supply and decouple using a quality

0.1µF ceramic capacitor.

48

VIN

Battery supply voltage. It is used for input voltage feed-forward to improve the input line transient

performance.

-

GND

The bias and reference ground for the IC. The GND connection for the ISL6265C is through the thermal

pad on the bottom of the package.

PIN(s)

SYMBOL(s)

DESCRIPTION