VN770P Datasheet, PDF (1/11 Pages) STMicroelectronics – QUAD SMART POWER SOLID STATE RELAY FOR COMPLETE H BRIDGE CONFIGURATIONS

®
VN770P
QUAD SMART POWER SOLID STATE RELAY
FOR COMPLETE H BRIDGE CONFIGURATIONS
TYPE
R_DS(on) *
I_OUT
VN770P
0.270 Ω
9A
* Total resistance of one side in bridge configuration
V _CC
26 V
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
and stuck-on to VCC. The low side switches are
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)
and in case of open open load (tpol) respectively.
This feature allows to discriminate the nature of
the detected fault. To protect the device against
September 1998
SO-28
short circuit and over current condition, the
thermal protection turns the integrated Power
MOS off at a minimum junction temperature of
140 ^oC. When this temperature returns to 125 ^oC
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 inductive loads with a typical voltage (Vdemag)
of -18V. This function allows to greatly reduces
the power dissipation according to the formula:
Pdem = 0.5 • Lload • (Iload)² • [(VCC+Vdemag)/Vdemag] • f
where f = switching frequency and
Vdemag = demagnetization voltage.
In this device if the GND pin is disconnected, with
VCC not exceeding 16V, both channel will switch
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
current (I_iss) flows into the Input pin in order to
supply the internal circuitry.
1/11