VN771

QUAD SMART POWER SOLID STATE RELAY

FOR COMPLETE H-BRIDGE CONFIGURATIONS

®

October 1998

SO-28

T YPE

VN771

0.140

Ω

14 A

26 V

* Total resistance of one side in bridge configuration

s

IDEAL AS A LOW VOLTAGE BRIDGE

s

VERY LOW STAND-BY POWER

DISSIPATION

s

OVER-CURRENT PROTECTED

s

STATUS FLAG DIAGNOSTICS ON UPPER

SIDE

s

OPEN DRAIN DIAGNOSTICS OUTPUT

s

UNDER-VOLTAGE PROTECTION

s

SUITABLE AS QUAD SWITCH

DESCRIPTION

The VN771 is

a device formed by

three

monolithic chips housed in a standard SO-28

package: a double high side and two Power

MOSFETs. The double high side are made using

STMicroelectronics VIPower technology; Power

MOSFETs are made by using the new advanced

strip lay-out technology This device is suitable to

drive a DC motor in a bridge configuration as well

as to be used as a quad switch for any low

voltage application. The dual high side switches

have built-in thermal shut-down to protect the

chip from over temperature and short circuit,

status output to provide indication for open load

in off and on state, overtemperature conditions

DUAL HIGH-SIDE SWITCH

From the falling edge of the input signal, the

status output, initially low

to signal a fault

condition

(overtemperature

or

open

load

on-state), will go back to a high state with a

different delay in case of overtemperature (tpovl)

This feature allows to discriminate the nature of

the detected fault. To protect the device against

short circuit and over current condition, the

thermal protection turns the integrated Power

MOS off at a minimum junction temperature of

140

the switch is automatically turned on again. In

short circuit the protection reacts with virtually no

delay, the sensor (one for each channel) being

located inside each of the two Power MOS areas.

This positioning allows the device to operate with

one channel in automatic thermal cycling and the

other one on a normal load. An internal function

of the devices ensures the fast demagnetization

of -18V. This function allows to greatly reduces

the power dissipation according to the formula:

where f = switching frequency and

In this device if the GND pin is disconnected, with

off.

Power MOSFETs

During

normal

operation, the

Input

pin

is

electrically connected to the gate of the internal

power MOSFET. The devices can be used as a

switch from DC to very high frequency.

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