LX1660 Ver la hoja de datos (PDF) - Microsemi Corporation

Número de pieza

componentes Descripción

Lista de partido

LX1660

ADVANCED PWM CONTROLLER

Microsemi Corporation 

PRODUCT DATABOOK 1996/1997

ADVANCED PWM CONTROLLER

PR O D U C T I O N D ATA S H E E T

LX1660/1661

Pin # Description

FUNCTIONAL PIN DESCRIPTION

EN

1 A low voltage at this pin puts the IC in sleep-mode.

OT ADJ

2 The purpose of this pin is to allow modulation of the OFF-time relative to the reference voltage. The OFF-time is

inversely proportional to the reference voltage. The inverting input of the upgrade voltage comparator is also

connected to this pin, when the voltage at this pin is below 0.7V, the controller shuts down.

SGND 3 This pin is the signal ground of the IC.

VREF

4 2V reference.

INV

5 This pin is the inverting input of the error comparator.

NINV/SS 6 This pin is the non-inverting input of the error comparator (LX1661 only: 40mV offset between this pin and error

comparator). This pin is pulled low during sleep-mode to allow soft-start function during start up.

HICCUP 7 A hiccup-mode capacitor connected to this pin adjusts duty cycle.

CT

8 The OFF-time is programmed by connecting a capacitor from this pin to ground.

CS-

9 This is the inverting input of the pulse-by-pulse current comparator.

CS+ 10 This is the non-inverting input of the pulse-by-pulse current comparator.

SYNCEN 11 This pin enables the synchronous (bottom) driver. A high voltage at this pin disables the synchronous driver.

VCC

BDRV

12 This is the IC supply voltage as well as the supply to the bottom MOSFET.

13 This is the gate drive to the bottom MOSFET

PGND 14 This is a separate ground for the top and bottom MOSFET.

TDRV 15 This is the gate drive to the top MOSFET.

VC1

16 This pin is a separate power supply input for the top drive.

Copyright © 1998

Rev. 1.1 7/98

5

Share Link: