7

HV9931

Pin #

Pin Name

Description

1

VIN

This pin is the input of a high voltage regulator.

2, 7

CS1, CS2

These pins are used to sense the input and output currents of the converter. They are the

inverting inputs of the internal comparators.

3

GND

Ground return for all the internal circuitry. This pin must be electrically connected to the ground

of the power train.

4

GATE

This pin is the output gate driver for an external N-channel power MOSFET.

5

PWMD

When this pin is pulled to GND, switching of the HV9931 is disabled. When the PWMD pin

is released, or external TTL high level is applied to it, switching will resume. This feature is

provided for applications that require PWM dimming of the LED lamp.

6VDD

This is a power supply pin for all internal circuits. It must be bypassed with a low ESR capacitor

to GND.

8RT

Oscillator control. A resistor connected between this pin and GND sets the PWM frequency. A

resistor connected between this pin and GATE sets the PWM off-time.

Pin Description