L9300 datasheet(71/178 Pages) STMICROELECTRONICS

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General purpose output (GPO)

12.1

GPO functional description

The device provides a low–side open drain general purpose output. This output can be used as a standard low–

side output or as a configurable interrupt generator through dedicated SPI bit in the Service Enable register.

Default configuration at device power on reset is IRQ functionality (GPO Configuration = 0): driver works as

General Purpose Output and it can be used to generate an interrupt to the microcontroller whenever a fault is

detected by the device. In case of interrupt generation GPO pin is driven low. The second functionality (GPO

Configuration = 1) is as low–side led driver (50 mA current capability): in this case the GPO output is directly

driven by the microcontroller through SPI command bit.

When used as LS driver GPO is equipped with on state and off state diagnostic. The off state diagnostic is made

of open load and short to GND checks; open load diagnostic can be disabled by SPI bit together with its diagnosis

bias current to use GPO output for LED mode operation; the short to GND off state diagnostic remains active and

behaves as usual.

During on state of the GPO output the driver (both in IRQ or LS configuration) is protected against short to battery

event through over current diagnostic: when an over current fault occurs the driver switches immediately off to

reduce the power dissipation, the fault is latched and is cleared by SPI read; the GPO driver is kept off until the

fault is cleared, then it is restarted automatically.

The turn on/off time is fixed; during turn-off the slope is controlled by external RC load.

Figure 42. GPO driver

GPO

Driver

Protection &

diagnosis

GADG1907171535PS

The table below lists the fault that can trigger an interrupt in IRQ mode; the trigger generation by these faults can

be masked through Service Fault Mask and Driver Fault Mask SPI registers.

L9300

General purpose output (GPO)

DS12258 - Rev 5

page 71/178

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