I have a motor contro board with a fault tolerant control, and we have used current sense on each one of the three phase of the brushless motor.
The sensor are LEM LTSR series, and they works perfectly, as they are closed loop hall-effect sensors.
Now we want to reduce sizes (and costs) of the PCB, and one option is a cheaper current sensor.
My choice fall under the allegro sensor, and I am investigating in the ACS712 and the ACS710.
I am more interested in the ACS710 because its higher bandwidth:
LEM LTSR->200KHz;
ACS710 ->120KHz;
ACS712 -> 80KHz;
For sensing a 20KHz PWM a BW of 120K is pretty enough (also 80K is enough, but is too far from the LEM series and we don't want to jump too much in changhing characteristics)
The measure will be an AC measure, and we already use a microprocessor analog input for acquisition.
I am evaluating the current size, which should be 6Amp, 12.5 or 25Amp, depending on the motor size of course.
For example if the motor will be a 15Amp max, I will use the 25Amps chip size.
=====MY QUESTION IS=====
If you have you already used the ACS710 or ACS712 (i suppose their internal circuitry similar)
It is usable for measuring the current generated from a PWM at 20KHz ??
I can read the datasheet, but sometimes there are things which aren't written on it ! 8-O
Such things comes out only when using the product ;-)
Do you think it works fine?
thanks a lot