Oznog
Active Member
I have a 24-bit LTC2400 I'm trying to use for measuring current on a 50mV @ 200 amp shunt. I'd like to measure low current leakage (under 1 amp) out of my deep cycle battery as well as the high currents.
I have it up and working. The problem is, I'm seeing a DC offset of 1.3mV when Vin is connected to ground at the ADC's pin (not ground somewhere far from the ADC). This constitutes an error of 5.2 amps so we're totally not in the ballpark here.
The LTC2400 lists the max offset error as 2ppm of Vref, which should mean 0.01mV. I've got 130 times that. There is no temp differential here so I'm ruling out a thermoelectric Seebeck effect. What's the problem here??
I have it up and working. The problem is, I'm seeing a DC offset of 1.3mV when Vin is connected to ground at the ADC's pin (not ground somewhere far from the ADC). This constitutes an error of 5.2 amps so we're totally not in the ballpark here.
The LTC2400 lists the max offset error as 2ppm of Vref, which should mean 0.01mV. I've got 130 times that. There is no temp differential here so I'm ruling out a thermoelectric Seebeck effect. What's the problem here??