Why DAC output connect with PWM output (PA4 and PB4) for current ref in the IHM07M1 board schematic?

[Fchun.1]

I am using IHM07M1 board

[Laurent Ca...]

Dear @Fchun.1​ 

I edited a little bit your message title.

Best regards

Laurent Ca...

[MK.1]

Hi,

I think so because the "reference current" is set by setting the voltage across the comparator. The voltage can be formed using a DAC or PWM. This is not a PWM output, but a PWM input...

[VMuni.1]

The IMH07M1's driver IC integrates an "uncommitted" comparator. This comparator can be used for controlling the current by shutting down the PWM pulse-by-pulse.

In motor control application the 2 input given to the comparator are :

1. Reference signal from microcontroller DAC
2. Voltage reading from currents shunts

So, the comparator will give output to shutdown the PWM pulse if current drawn by motor is more than set value.

You can find detailed information in this application notes

https://www.st.com/resource/en/application_note/dm00236305-generalpurpose-timer-cookbook-for-stm32-microcontrollers-stmicroelectronics.pdf