Open drain bidirectional logic pins. These pins must be connected to an external pull
up resistor. When externally pulled low, they disable half-bridge A or B. In case of
fault detection (thermal shutdown of a high side FET or excessive ON state voltage
drop across a low side FET), these pins are pulled low by the device (see truth table in fault condition).
In case of a fault condition the DIAGX/ENX pin is considered as an output pin by the device.
The fault conditions are:
● overtemperature on one or both high sides
● short to battery condition on the output (saturation detection on the low side power MOSFET)
Possible origins of fault conditions may be:
● OUTA is shorted to ground → overtemperature detection on high side A.
● OUTA is shorted to VCC → low side power MOSFET saturation detection.
When a fault condition is detected, the user can know which power element is in fault by
monitoring the INA, INB, DIAGA/ENA and DIAGB/ENB pins.