The LTC1594LIS#PBF is a micropower sampling serial I/O Analog-to-digital Converter (ADC) that features 4-channel multiplexers. It typically draws only 160μA of supply current when converting and automatically power down to a typical supply current of 1nA between conversions. The 12-bit switched-capacitor successive approximation ADC includes a sample-and-hold. On-chip serial ports allow efficient data transfer to a wide range of microprocessors and microcontrollers over three or four wires. This, coupled with micropower consumption, makes remote location possible and facilitates transmitting data through isolation barriers. The circuit can be used in ratiometric applications or with an external reference. The high impedance analog inputs and the ability to operate with reduced spans allow direct connection to sensors and transducers in many applications, eliminating the need for gain stages.