The MAX110/MAX111 analog-to-digital converters (ADCs) use an internal auto-calibration technique to achieve 14-bit resolution plus overrange, with no external components. Operating supply current is only 550µA (MAX110) and reduces to 4µA in power-down mode, making these ADCs ideal for high-resolution battery-powered or remote-sensing applications. A fast serial interface simplifies signal routing and opto-isolation, saves microcontroller pins, and offers compatibility with SPI, QSPI, and MICROWIRE. The MAX110 operates with ±5V supplies, and converts differential analog signals in the -3V to +3V range. The MAX111 operates with a single +5V supply and converts differential analog signals in the ±1.5V range, or single-ended signals in the 0V to +1.5V range. Internal calibration allows for both offset and gain-error correction under microprocessor (µP) control. Both devices are available in space-saving 16-pin DIP and SO packages, as well as an even smaller 20-pin SSOP package.