VN770P

QUAD SMART POWER SOLID STATE RELAY

FOR COMPLETE H BRIDGE CONFIGURATIONS

®

September 1998

SO-28

T YPE

VN770P

0.270

Ω

9A

26 V

* Total resistance of one side in bridge configuration

s

IDEAL AS A LOW VOLTAGE BRIDGE

s

LINEAR CURRENT LIMITATION

s

VERY LOW STAND-BY POWER

DISSIPATION

s

SHORT CIRCUIT PROTECTED

s

STATUS FLAG DIAGNOSTICS

s

OPEN DRAIN DIAGNOSTICS OUTPUT

s

INTEGRATED CLAMPING CIRCUITS

s

UNDER-VOLTAGE PROTECTION

s

ESD PROTECTION

DESCRIPTION

The VN770P is a device formed by three

monolithic chips housed in a standard SO28

package: a double high side and two low side

switches. Both the double high side and low side

switches are made using STMicroelectronics

VIPower 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

two OMNIFET types (fully autoprotected Power

MOSFET in VIPower

™ technology). They have

built-in thermal shut-down, linear current limitation

and overvoltage clamping. Fault feedback for

thermal

intervention

can

be

detected

by

monitoring the voltage at the input pin.

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.

LOW-SIDE SWITCHES

During

normal

operation, the

Input

pin

is

electrically connected to the gate of the internal

power MOSFET. The device then behaves like a

standard power MOSFET and can be used as a

switch from DC to 50 KHz. The only difference

from the user’s standpoint is that a small DC

supply the internal circuitry.

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