SiP43101

Vishay Siliconix

New Product

Document Number: 72640

S-32451, Rev. A—01-Dec-03

www.vishay.com

5

FUNCTIONAL BLOCK DIAGRAM

Short Citcuit

Thermal Shut Down

Reset

UVLO

Reference

Control

Logic

FAULT

GND

DETAILED OPERATION

Turn On Delay

The turn on delay prohibits the output switches from being

8 V and the undervoltage condition no longer exists. The

current source charges the capacitor from GND to 4.7 V. A

through 4 V and enables the output switches. The delay time

is a function of the capacitor value and is defined as

1.6 ms/nF.

An external switch can be connected across the capacitor to

disable the output switches and reset the time delay.

Short Circuit and Overcurrent indication

When an overcurrent or short circuit condition occurs on

either switch, the SiP43101 enters a hiccup current limiting

down to 3 V, thus turning off the output switches, and then is

charged up to 4 V by a 2.5-mA internal current source, thus

turning the switches on again. If the overcurrent or short circuit

condition remains this cycle will continue. The switches are

enabled at a very low duty cycle, minimizing the power

dissipation and protecting the switches from damage.

The FAULT output will switch to GND, indicating that an

overload condition or short circuit condition exists.