ELECTRICAL CHARACTERISTICS (continued)

PROTECTION AND DIAGNOSTICS

Symb ol

Parameter

Test Cond ition s

Mi n.

Typ .

Max.

Un it

•) Status Voltage Output

Low

0.4

V

Under Voltage Shut

Down

2. 5

5

V

•) Status Clamp Voltage

5. 5

6

-0. 7

-0.3

V

V

Switch-off T ime in

Short Circuit Condition

at Start -Up

Ω

1.5

5

ms

Over Current

Ω

28

A

Average Current in

Short Circuit

Ω

0.9

1.8

A

Open Load Current

Level

5

70

mA

Leakage Current

Of f St ate

60

µA

Thermal Shut-down

Temperat ure

140

160

Reset Temperature

125

145

exceed 10 mA at the input pin.

(

•) Status determination > 100 µs after the switching edge.

temperature reaches thermal shutdown temperature.

FUNCTIONAL DESCRIPTION

The device has a diagnostic output which

indicates

open

circuit (no

load)

and

over

temperature conditions. The output signals are

processed by internal logic.

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

temperature returns to about 125

automatically turned on again. To ensur the

junction temperature range it is necessary to limit

the voltage drop across Drain and Source (pin 3

and 5) at 29 V. The device is able to withstand a

load dump according the test pulse 5 at level III of

the ISO TR/1 7631.

to 36V. Power dissipation increases and the

device turns off if junction temperature reaches

thermal shutdown temperature.

PROTECTING

THE

DEVICE

AGAINST

REVERSE BATTERY

The simplest way to protect the device against a

continuous reverse battery voltage (-26V) is to

insert a Schottky diode between pin 1 (GND) and

ground, as shown in the typical application circuit

(fig. 3).

The consequences of the voltage drop across

this diode are as follows:

respect to power GND).

If there is no need for the control unit to handle

external analog signals referred to the power

GND, the best approach is to connect the

reference potential of the control unit to node [1]

(see application circuit infig. 4), which becomes

the common signal GND for the whole control

board.

place and no negative voltage appears on the

INPUT pin; this solution allows the use of a

standard diode, with a breakdown voltage able to

handle any ISO normalized negative pulses that

occours in the automotive environment.

VN02H

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