UVLO flag always on

[BL1]

Hi,

Using IHM03A1, I'm driving a 48V-9A motor.

According to @Cristiana SCARAMEL (Employee)​ recommandations, I add 15mOhm/3W resistances in parallel of R1 and R2, so R1 and R2 value is now 13mOhm, I choosed current mode, set run current to 10.2A (132.81mV) and overcurrent threshold to 13.22A (343,75mV).

After have it working on SPINFamily Evaluation Tool 3.2 with STnucleo-f401re, I set it up on Arduino. All was working identically and fine.

One day (like any other days end), we stopped the motor, turned all off and when we turned it on next day, nothing was working (same wiring, same configuration, ...).

UVLO flag is always on, avoiding current to be sent to motor. All is stuck in HiZ mode.

I've tried again with SPINFamily Evaluation Tool 3.2 and STnucleo-f401re, exactely the same configuration as previous working one, but rame results as with Arduino (UVLO flag is always on, avoiding current to be sent to motor. All is stuck in HiZ mode).

Do you have any idea about what happened? or how to make it work again ? (due to current semiconductor crisis there is none on sale ...)

Thanks,

Laetitia

[BL1]

Mesured voltage:

Vin = 48V

VA-=VA+=VB-=VB+=0

Vboot = 48V

VS=48V

[Cristiana SCARAMEL]

Hi @BL​,

VBOOT = VS means that the charge pump is not working.

One option is that the charge pump external components may have been damaged,

the other option is that the VCC is not present, check the voltage level at the pin.

[BL1]

Hi @Cristiana SCARAMEL​ ,

VCC = 6.5V when all is powered and configured and ULVO rised.

When board is powered but not setup, VCC = 3.1V

HMI03A1 VCC is measured around C7.

[Cristiana SCARAMEL]

Hi @BL​,

the X-NUCLEO-IHM03A1 board is designed to receive the 3.3V from NUCLEO board (through VDD).

So if the two board are connected but the VS is not powered on the VCC (across C7) you can read about 3.1 V due to the voltage drop on D9.

When you apply the VS the VCC voltage should rise to 7.5 or 15 V according to the VCCVAL bit value in the CONFIG register.

What VCC value did you set?

Anyway, if you read VCC = 6.5 V the device is set properly in UVLO condition according to the UVLO thresholds (VCCthOff, DeltaVBOOTthOff).

An option is that the linear regulator is overloaded or damaged.