The ADC121S101 is a low-power, single-channel CMOS 12-bit analog-to-digital converter with a high-speed serial interface. Unlike the conventional practice of specifying performance at a single sample rate only, the ADC121S101 is fully specified over a sample rate range of 500 ksps to 1 Msps. The converter is based upon a successive-approximation register architecture with an internal track-and-hold circuit. The output serial data is straight binary, and is compatible with several standards, such as SPI™, QSPI™, MICROWIRE, and many common DSP serial interfaces. The ADC121S101 operates with a single supply with a range from 2.7 V to 5.25 V. Normal power consumption using a 3 V or 5 V supply is 2 mW and 10 mW, respectively. The power-down feature reduces the power consumption to as low as 2.6 µW using a 5-V supply. The ADC121S101 is packaged in 6-pin WSON and SOT-23 packages. Operation over the temperature range of –40°C to 125°C is specified.