Data Sheet

14

Rev 1.0, 2012-10-01

TLE 8088 EM

Power Drivers

6

Power Drivers

6.1

Low-Side Drivers

The power stages are built by N-channel power MOSFET transistors. The channels are universal multi channel

switches but mostly suitable to be used in Engine Management Systems. Within an Engine Management System,

the best fit of the channels to the typical loads is:

•

Channel 1 for injector, valves or similar sized solenoids with a maximum operation current requirement of 2.6A

•

Channel 2 for malfunction indication lamps or other resistive loads with a maximum current requirement of 3A

Figure 7

Low-side Switches

Channel 1 has open load detection in off state. If an open load condition persists for a time longer than the filter

time

t

be released after the time

t

In over-current situation channel 1 will be switched off and kept latched. Additionally the ST signal will be set to

low after the settling time

t

t

During an over-temperature event the ST signal is set to low and will turn back to high if the failure condition is

disappeared (see Table 1).

In over-current situation the channel 2 will be switched off, and after typ. 4ms the channel will be switched on

again. Channel 2 is also over-temperature protected. In over-temperature situation channel 2 will be switched off

and will restart if the junction temperature falls by thermal shutdown hysteresis

T

Table 1

Truth Table for Diagnostics of CH1

Open Load

Over Current

Over Temperature

ST

Status

0

0

0

1

Normal operation

1

x

x

0

Failure detected

x

1

x

0

Failure detected and latched

Channel 1 is switched off

x

x

1

0

Failure detected and channel 1 is

switched off

Failure Situation

ST

0 = Situation doesn’t exist 1 = Normal operation

1 = Situation exists

0 = Failure detected

X = 0 or 1

OUT

V

DS

GND

L,

OUT

V

DS

GND

R

Channel 1

Channel 2