The MAX11644/MAX11645 low-power, 12-bit, 1-/2- channel analog-to-digital converters (ADCs) feature internal track/hold (T/H), voltage reference, clock, and an I2C-compatible 2-wire serial interface. These devices operate from a single supply of 2.7V to 3.6V (MAX11645) or 4.5V to 5.5V (MAX11644) and require only 670μA at the maximum sampling rate of 94.4ksps. Supply current falls below 230μA for sampling rates under 40ksps. AutoShutdown™ powers down the devices between conversions, reducing supply current to less than 1μA at low throughput rates. The MAX11644/MAX11645 each measure two single-ended or one differential input. The fully differential analog inputs are software configurable for unipolar or bipolar, and single-ended or differential operation.