The LTC2946 is a high or low side charge, power and energy monitor for DC supply rails in the 0V to 100V range.
|An integrated +-0.4% accurate, 12-bit ADC and external precision time base (crystal or clock) enables measurement accuracy better than +-0.6% for current and charge, and +-1% for power and energy. A +-5% accurate internal time base substitutes in the absence of an external one. All digital readings, including minimums and maximums of voltage, current and power, are stored in registers accessible by an I2C/SMBus interface. The part 19s wide operating range makes it ideal for monitoring board energy consumption in blade servers, telecom, solar and industrial equipment, and advanced mezzanine cards (AMC).|
LTC2946 datasheet in this link