Data Brief

For further information contact your local STMicroelectronics sales office.

July 2007

Rev 2

1/10

10

L9374

Four channel valve driver

Features

diagnostic

– 2 PWM controlled channels (0.2

Ω typ)

–2 current controlled channels with 6%

accuracy (0.3

Ω typ)

5MHz with diagnosis

– Over load protection

– Open Load

– Under-current

– Under Voltage

– Temperature Warning and Shutdown

– Power or Signal GND loss

– Freewheeling diode loss

– Silent valve driver test

Description

The L9374 is a four channel low side driver with

integrated recirculation diodes. The switching of

the channels is programmable via a SPI (Serial

Peripheral Interface). The main time base is given

by an external clock via CLKin. The Clock Unit

monitors this external clock and provides the

system clock for all timings.

A Synchronization Unit is used to monitor the SPI

communication and provides a sync signal for the

channel activation.

The Output Duty Cycle for each channel can be

programmed individually and will be activated by

the Set Point Unit. Is possible to program two

output Duty Cycles per channel with a block of 16

SPI commands as well as an individual Duration

Time for each channel actuation. Both information

are stored in the PWM and in the Counter

Configuration Register respectively.

The PWM Controller translates the programmed

digital duty cycle value in a PWM signal which

controls the output.

For the current controlled channels the target

current value is programmed. It is also possible to

program two different target currents. The target

current is compared with the real load current.

The output duty cycle is then calculated with an

Arithmetic Logic Unit. As base for the calculation

a load model is used respecting the resistivity of

the load, the supply voltage as well as the

internal recirculation path. To check the

plausibility of the current controller all measured

and calculated values are available and

accessible via SPI.

All channels are equipped with a load Diagnostic.

This allows to detect an open load in off condition

as well as an under current in on condition. The

power stage is protected against over current and

over temperature. A weak connection in power

ground or in the recirculation path is monitored.

All monitored functions can be read out in a serial

diagnostic protocol dedicated for each channel

via SPI..

Table 1.

Device summary

Order code

Package

Packing

L9374

PowerSO-36 (slug down)

Tube

L9374XP

PowerSSO-36 (exp. pad)

Tube

PowerSO-36

PowerSSO-36

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