Hello,
Here is an interresting application note from STM about the différent current sensing with their pros and cons of each that I share with you :
https://www.st.com/resource/en/application_note/dm00666970-current-sensing-in-bldc-motor-application-stmicroelectronics.pdf
You will find in this document an alternative to the very good INA240 : the TSC2011.
Thanks Marc thats a good read.
The TSC2011 has amazing common mode range but its a big chip compared to the competitors. I found it hard to place in my layouts. But I’m working on smaller designs. On a larger ESC it won’t be an issue.
Still, its freaking expensive, around 2 buck.
For low cost and low power design, 0.1 buck opamp migh be enough. Just a lm358 and some 1% resistors.
Heres a 10X difference amplifier with 1.65V DC bias. The CMRR is not very satisfied but is good enough. So a RC filter is placed at the output to reduce glitch.
