TS19450

Taiwan Semiconductor

Document Number: DS_P0000187

5

Version: B15

FUNCTION BLOCK DIAGRAM

PIN DESCRIPTION

PIN NO.

NAME

FUNCTION

1

VIN

This pin is the input of 8V~450V linear regulator

2

CS

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

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

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

3

GND

Ground return for all 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-CH Power MOSFET

5

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

VDD

This is the power supply pin for all internal circuits.

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

7

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.)

8

RT

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

RT and GND, the IC operates in constant frequency mode. When the resistor

is connected between RT and GATE, the IC operates in constant off-time

mode.