The ADC121S655 is a 12-bit, 200 kSPS to 500 kSPS sampling Analog-to-Digital (A/D) converter that features a fully differential, high impedance analog input and an external reference. The reference voltage can be varied from 1.0V to VA, with a corresponding resolution between 244µV and VA divided by 4096. The output serial data is binary 2's complement and is compatible with several standards, such as SPI, QSPI, MICROWIRE, and many common DSP serial interfaces. The differential input, low power consumption, and small size make the ADC121S655 ideal for direct connection to transducers in battery operated systems or remote data acquisition applications. Operating from a single 5V supply, the supply current when operating at 500 kSPS is typically 1.8 mA. The supply current drops down to 0.3 µA typically when the ADC121S655 enters power-down mode. The ADC121S655 is available in the VSSOP-8 package. Operation is specified over the industrial temperature range of −40°C to +105°C and clock rates of 3.2 MHz to 8 MHz.