6

HV9910B

Pin Description

Block Diagram

Pin #

Function

Description

8-Lead SOIC

16-Lead SOIC

1

1

VIN

This pin is the input of an 8.0 - 450V linear regulator.

24

CS

This pin is the current sense pin used to sense the FET current by means

of an external sense resistor. When this pin exceeds the lower of either the

internal 250mV or the voltage at the LD pin, the GATE output goes low.

3

5

GND

Ground return for all internal circuitry. This pin must be electrically con-

nected to the ground of the power train.

48

GATE

This pin is the output GATE driver for an external N-channel power

MOSFET.

5

9

PWMD

This is the PWM dimming input of the IC. When this pin is pulled to GND,

the GATE driver is turned off. When the pin is pulled high, the GATE driver

operates normally.

6

12

VDD

This is the power supply pin for all internal circuits.

It must be bypassed with a low ESR capacitor to GND (≥0.1μF).

713

LD

This pin is the linear dimming input and sets the current sense threshold as

long as the voltage at the pin is less than 250mV (typ).

814

RT

This pin sets the oscillator frequency. When a resistor is connected be-

tween RT and GND, the HV9910B operates in constant frequency mode.

When the resistor is connected between RT and GATE, the IC operates in

constant off-time mode.

-

2, 3, 6, 7, 10,

11, 15, 16

NC

No connection

POR

250mV

RT

PWMD

GATE

VDD

VIN

LD

CS

GND

S

R Q

Blanking

Oscillator

Regulator

+

-

+

-