www.st.com/vipower

VN808 internal block diagram

The VN808 has built-in junction over-temperature

protection which is thermally independent for each of

the eight channels, it has a current limitation (1.1A

typical), and a fast demagnetization block clamped at

–52V typical. Thanks to the built-in protection each

channel is self-protected against load short-circuiting

and overloading. The device is able to manage

large inductive loads, however care must be taken

of the power dissipation related to the switching

frequency in free-wheeling conditions. Both under-

voltage protection and loss of ground protection with

shutdown are added. For the very first time a case

over-temperature protection is integrated into the

150m

Ω per channel at 25°C, while the operating voltage

is inside the industrial range of 10.5V to 45V.

VN808 in a typical programmable logic controller application

VN808

BUS

ASIC

CL

CSLK

RX

TX

Lamps

Valves

Relays

[

m

Ω]

[A]

0.7

[V]

Double integrated thermal protection exists in VN808

in the form of:

Junction temperature detection (TTSD) and

protection, related to the single channel;

Case temperature detection (TCSD) and protection,

related to the whole device dissipation.

The case temperature protection avoids PCB

degradation if a large number of channels are

overloaded. In fact the TCSD acts only on the

overloaded channel; channels that are not overloaded

continue to operate normally.

10.5 to 36

41

The VN808 is the first octal single chip high-side

driver developed in VIPower M0-3 technology. Both

the control and power stage use N-MOS technology.

VN808 has 8 different channels with single

protection and diagnostic functions integrated on

a single chip. The VN808 has been developed

considering the needs of the industrial process

control market.

High-power capability PowerSO-36;

Vcc/2 compatible inputs;

Junction over-temperature protection;

Case over-temperature protection for thermal

independence of the channel;

Current limitation;

Shorted load protection;

Under-voltage shutdown;

Protection against loss of ground;

Very low stand-by current;

Compliance with 6100-4-4 IEC test up to 4.4kV.

Vcc

GND

X8

Input 1

Input 2

Input 8

Status

VN808

Undervoltage

Clamp

Clamp

Current lim.

Junction Temp

Detection

Case Temp. Detec.

Lo

gic

[V]

8 x 150