L9332 datasheet(12/17 Pages) STMICROELECTRONICS

12 / 17 page

Circuit description

L9332

12/17

Circuit description

The L9332 is a quad low side driver for inductive loads like valves in automotive

environment. The internal pull down current sources at the ENable and INput pins assure in

case of open input conditions that the device is switched off. An output voltage slope

limitation for du/dt is implemented to reduce the EMI. This is valid up to the clamping voltage

VZ. This active flyback voltage limitation clamps the output voltage during the flyback phase.

It is alowed to connect two power stages from one device in parallel if external free wheeling

diodes are used in the application. For the Ron calculation the parallel resistivity is expected.

The nominal current is 70% of the sum of the nominal currents of the used channels.

Each driver is protected against short circuit at VOUT < 32 V and thermal overload. In short

circuit condition the output will be disabled after a short delay time tD. The thermal disable

for TJ > 175°C of the output will be reset if the junction temperature decreases about 20 °C

below the disable threshold temperature.

The overtemperature, overload and groundloss information is stored until IN is low.

For the real time error diagnosis the voltage and the current of the outputs are compared

with internal fixed values VOUV for OFF and IOUC for ON conditions to recognize open load

in OFF and ON conditions.

The diagnostic output level in connection with different ENable and INput conditions allows

to recognize different fail states, like overtemp, short to VS, short to GND, bypass to GND

and disconnected load (see diagnostic table).

The diagnostic output is protected against short circuit. Exceeding the over load current

threshold IOOC, the output current will be limited internally during the diagnostic overload

delay switch-off time tD.

The device complies the ISO pulses imposed to the supply voltage of the valves without any

failures of the functionality. Therefore some diagnostic functions are internal filtered. The

diagnostic table shows the corresponding filter time for each detected signal.

Figure 4.

tEO clamping time

VO1-4

tEO

05UG32_27

L9332 Datasheet(PDF) 12 Page - STMicroelectronics