CIRCUIT DESCRIPTION

The L93PI is a quad low side driver for lines,

lamps or inductive loads in automotive and indus-

trial applications.

All INputs are TTL or CMOS compatible. This al-

lows the device to be driven directly by a micro-

controller. For the noise immunity, all inputs have

a Schmitt-trigger with a hysteresis of typ. 100mV.

Each input stage has an input voltage protection

from -24V to 45V. The device can be activated

with a ’high’ signal on ENable input. ENable ’low’

switches the device into the sleep mode. In this

mode the quiescent current is less than 10

µA. A

high signal on PRoGramming input changes the

signal transfer polarity from noninverting into the

inverting mode. Normally this pin is connected to

VS or GND. These pins (PRG and EN) are inter-

nally fixed at low status by open input condition.

Independent of the PRoGramming input, the

OUTput switches off, if the signal INput pin is not

connected.

Each output driver has a current limitation of min

0.4A and a seperate thermal shut-down. The ther-

mal shut-down deactivates that output which ex-

ceeds Temperature switch off level. About 20K

below this temperature threshold the output will

be activated again. This means, that each output

is able to sink continuously 285mA without acti-

vating thermal shut-down at 85°C ambient tem-

perature (SO20). The slew rate of the output is

limited to max. 14V/

µs to reduce the electromag-

netic interference, but not for the enable transfer

characteristic (see fig. 1). An integrated active fly-

back voltage limitation clamps the output voltage

during the flyback phase of inductive loads to typ.

50V. The power DMOS switches ON, if the device

is enabled and the OUTput swings below ground.

This protection avoids the activation of parasitics

inside the power DMOS.

The DIAGnostic is an open drain output. The logic

status depends on the PRoGramming pin. If the

PRG pin is ’low’ the DIAG output becomes low, if

the device works correctly.

At thermal shut-down of one channel, discon-

nected ground or supply voltage the DIAGnostic

output becomes high. If the PRG pin is ’high’ this

output is switched off at normal function and

switched on at overtemperature.

DIAGNOSTIC TABLE

Pins

EN

PRG

IN

OUT

DIAG

Normal function

H

L

L

L (on)

L (on)

H

L

H

H (off)

L (on)

H

H

L

H (off)

H(off)

HHHL (on)

H(off)

L

X

X

H (off)

H(off)

Overtemperature,

disconnected ground or

supply voltage

H

L

X

H (off) *

H (off)

Overtemperature

H

H

X

H (off) *

L (on)

X = not relevant * selective for each channel at overtemperature

L93PI

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