CIRCUIT DESCRIPTION

The L9346 is a quad low side driver for inductive

loads like valves in automotive environment. The

internal pull down current sources

at the EN-

ABLE and INPUT pins assure in case of open in-

put conditions that the device is switched off. An

output voltage slope limitation for du/dt is imple-

mented to reduce the EMI. An integrated active

flyback voltage limitation clamps the output volt-

age during the flyback phase to 50 V.

Each driver is protected against short circuit at

condition the output will be disabled after a short

180

°C of the output will be reseted if the junction

temperature decreases about 20

°C below the dis-

able threshold temperature.

The overtemperatureinformation is stored until IN = L.

For the real time error diagnosis the voltage and

the current of the outputs are compared with in-

≥ 20 KΩ,

Ω) in OFF and ON conditions.

each other output in OFF condition with a fixed

offset of

suppress the

phases of the compared output, the

∆VOUV diag-

nostic includes a latch function.

diagnostic signal is reseted by a latch. To activate

again this kind of diagnostic a low signal at the

correspondent INPUT or the ENABLE pin must

be applied (see also Fig.3). The outputs 1 and 4

are compared for

are compared.

The diagnostic output level in connection with dif-

ferent ENABLE and INPUT conditions allows to

recognize different fail states, like overtemp, short

dis-

connected load (see diagnostic table).

The diagnostic output is protected against short

circuit. Exceeding the over load current threshold

during the diagnostic overload delay switch-off

The device complies the ISO pulses imposed to

the supply voltage of the valves without any fail-

ures of the functionality.

5V

t

t

5V

t

5A

3A

IN

V

I O

I OOL

I OUC

D

V

t

DOL

Figure 3. Diagnostic Overload Delay Time

L9346

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