INA240 version

[PixelMutation]

The version of INA240 is not specified in the BOM. According to the datasheet there are 4 versions. To clarify, is it INA240A2, since that is what is used on the regular FOC shield?

[GovP]

Also curious!
Tried with A3 and they (specifically the INA240 over 3 attempts) keep frying. Could be another issue e.g. voltage but wondering if using the wrong spec.

[askuric]

Hey guys,
Sorry for the delay, I've forgotten to reply.
It depends on the currents you're interested in measuring.

The board has a resistor of 1milliOhm (it can be changed as well) and since usual ADC voltage is 3.3V. INA240 gains are:

• A1 10V/V
• A2 50V/V
• A3 100V/V
• A4 200V/V

The current range will be:

max_current = 3.3V/2 / 0.001milliOhm / gain (V/V)

So A1 would give you a range of 3.3/2/0.001/10=165 Amps :D
A2 will give you a range of 3.3/2/0.001/50=33 Amps
With A3 range will be 3.3/2/0.001/100=16.5 Amps
And for A4 3.3/2/0.001/200= 8.25 Amps

So in my case I've used the A2. But the rule of thumb would be to use the highest gain possible for your application.