Quick mother startup

AN4370

10/23

DocID025336 Rev 1

3

Quick mother startup

Assuming no ongoing failure condition that would hinder the gate drivers to work (in fact

there are several errors that disable the gate drivers), the following steps are the minimum

ones required for a quick startup of the motor:

•

Pull the DISABLE pin low

•

Send a Clear all status register command to the driver

•

Program the PCSO/PCSI bits with any value different from zero

•

Configure the BEMFIP properly (not needed if the BEMFIP is not used)

•

Start triggering the Watchdog

•

Drive the IHx and the ILx inputs properly to drive the MOSFETs and make the motor

spin

If any failing condition that disables the gate drivers will still be ongoing, before running any

of the foresaid steps the failing conditions affecting the gate drivers should be all removed.

For instance, in case of a power supply slow ramp, the application, with the device exiting

from a POR, could face a temporary (the time span within this condition will depend on the

ramp up slope) VDD_UV condition, which will disable the gate drivers. To overcome this

situation the microcontroller should continuously send clear all status registers commands

until VDD_UV failures will no longer be detected.