Hello, I am using STPM34 smart metering chip to read 230 VAC voltages and currents. I am using 3 chips on 1 board:
First 2 STPM34 measure 3 phases of 230 VAC voltages and currents, 3 STPM34 measures 16 multiplexed current channels and no voltage.
I am communicating with all chips via SPI interface, I use CRC to verify communication. I also use auto Latch function on all chips and 2x current gain on all channels, these are all the settings I change every time it powers on. The problem I face is after long working time, from a few days to a week, I start to get wrong values from some chips. Sometimes I get wrong voltages, sometimes wrong currents. Currently I am getting 428 V on voltage channel that is measuring 250 VAC on a device that runs for 12 days. Previously I was getting 0 A on a current channels of a device that was running for 5 days. It depends on device that I use. I have 5 PCBs with assembled devices, currently testing 2 on long run and both return wrong values after some time. Could this be error in chip design ? What is the solution for this problem? I am highly speculating that this is a chip flaw because I check CRC after each communication frame.
