I am building a battery monitoring device and planning on measuring voltage drop across a current shunt, amplifying, and reading into an external (12-bit) ADC chip to get a value of the resolution I desire.
The problem I am requesting help with is finding a low-power ADC that accepts +- voltage for the signal or some kind of workaround of that without losing too much resolution.
I am using a +- 5V linear regulator for power supply and a 0.1m ohm precision shunt, planning to accurately measure +- 200A (charging and discharging) but cannot find an ADC chip that suits my needs.
The TC7109 has dual rail supply and can take both positive and negative voltages into ADC but has quite high power usage (>1W).
Something like the the MCP3201 would be ideal (especially because I am already using planning to use SPI for SD card operations) but its input range doesn't extend into the negative.
Is there a way that I could use a cheaper, more convenient chip like the MCP3201 to measure positive and negative voltages without sacrificing precious resolution?
Below is a (very simple) circuit schematic of the proposed circuit before ADC: