INA210 – Current Sensing

These scope pictures are from MC4X15A measured at 0,5A and 0,7A on the PSU. The yellow is just the pulse trigger, the cyan is the actual CSense on ch1. The cyan line is the CSense. CSense seemed to increase in average as I increased voltage. Phase current is larger, so a 200mV signal might be ok-ich – I have not done the math exact – 0.5A is ca 0,1V and looking at the scope average 64mV that is 0,32A while 77mV is 0,39A – the math don’t add up so I am not sure what I am looking at.

Measuring the shunt with a multimeter I get 0,3mV which indicate 0,3A while the PSU indicate 0,5A – Increasing to 0,7A I measure 0,5mV which calculate to 0,5A – so the shunt seems to be “ok” with a 0,2A difference from PSU – but keep in mind that numbers are not exact here and it’s a difference between PSU current and phase current.

I have a filter AFTER INA210 that I will remove + I want to look at a non-amplified signal on CH2 to compare. I also need to sample and compute in SW with an actual ADC – I can only repeat that I am not convinced by INA210 yet. I will add proper load later so we can test higher currents. I did test 0.9A, but the scope pic did not convince me.

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