Hey @Valentine , do you have experience with using the ACS712 while powering it with 3V3?
I want to use this sensor with Nucleo32G431KB.
Do i have to power the current sensors with 5V and use the voltage divider network, or would the 3V3 approach be also ok?
I tested the ACS712 with 3V3 (from the internal Nucleo LDO), and the sensors give a good reading (±10mA from target), although the sensitivity went from 100mV per Amp, to 60mV per Amp. I can test only on DC current, so i dont know what will be the impact on faster readings, while measuring current on motor phases.
What power structure for sensors and Nucleo to use, to ensure good voltage reference on sensors and AVDD pin?
I wanted to power the 3 ACS712 sensors and Nucleo with the same 3V3 LDO.
Additionally i have 3 Hall Sensors that are powered with 5V LDO, and additional 3V3 LDO for pull-up resistors. The LDO’s for Hall Sensors only power the Hall Sensors, in order to provide a switching digital signal with its own power supply, separated from the analog devices.
I was analyzing this power tree but im not sure about a good power structure.
The power structure in my project looks like that:
So far i am not using the AVDD pin, only providing power to the Nucleo through the 3V3 pin.
I’m not sure if that’s correct, becouse on the STM32G4 power tree schematics, it looks like 3V3 is supplied to the AVDD and VDD by the internal LDO, only if using 5V or VIN pins to supply the Nucleo.
I will be grateful for any help.