The MAX11644/MAX11645 low-power, 12-bit, 1-/2channel 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 670A at the maximum sampling rate of 94.4ksps. Supply current falls below 230A for sampling rates under 40ksps. AutoShutdownTM powers down the devices between conversions, reducing supply current to less than 1A 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. The full-scale analog input range is determined by the internal reference or by an externally applied reference voltage ranging from 1V to VDD. The MAX11645 features a 2.048V internal reference and the MAX11644 features a 4.096V internal reference. The MAX11644/MAX11645 are available in an 8-pin MAX package. The MAX11644/MAX11645 are guaranteed over the extended temperature range (-40C to +85C). For pin-compatible 10-bit parts, refer to the MAX11646/MAX11647 data sheet.