Hi,
One of customers is using the UCD9244+UCD7242 power stage to power up our C6678 DSP. The 4 VID bits are tied high using pull-up resistors as the DSP that drives them has open-drain output. So, all the VID bits are at logic 1.They are not sending any command over PMBus to configure the high or low voltage threshold nor the mode of VID(4/6 or 8). I read in another post(
) that the unused VID pins can be floated without any adverse effect. Conversely, does it affect the device function when they are actually pulled to a logic level(1) but the proper command is not sent over PMBus to configure the state machine?
The issue observed is that after some time(randomly between 2 min to 10 min), the output falls to zero, i.e. the PWM pulses from the UCD9244 cease. There is no over current or over temperature fault as confirmed by the current and temp monitoring pins of UCD7242.
Just wanted a confirmation on the VID
