The AD7898 is a fast 12-bit ADC that operates from a single 5 V supply and is housed in a small 8-lead SOIC package. The part contains a successive approximation A/D converter， an onchip track/hold amplifier， an on-chip clock， and a high speed serial interface. The AD7898 offers two modes of operation. In Mode 0， conversion is initiated by the CONVST input and the conversion process is controlled by an internal clock oscillator. In this mode， the serial interface consists of three wires and the AD7898 is capable of throughput rates up to 220 kSPS. In Mode 1， the conversion process is controlled by an externally applied SCLK with data being accessed from the part during conversion. In this mode， the serial interface consists of three wires and the AD7898 is capable of throughput rates up to 220 kSPS. In addition to the traditional dc accuracy specifications， such as linearity and full-scale and offset errors， the AD7898 is specified for dynamic performance parameters， including harmonic distortion and signal-to-noise ratio. The part accepts an analog input range of ±10 V （AD7898-10） and ±2.5 V （AD7898-3）， and operates from a single 5 V supply， consuming only 22.5 mW max. The part is available in an 8-lead Standard Small Outline Package （SOIC）.