The AD974 is a four-channel， data acquisition system with a serial interface. The part contains an input multiplexer， a highspeed 16-bit sampling ADC and a +2.5 V reference. All of this operates from a single +5 V power supply that also has a powerdown mode. The part will accommodate 0 V to +4 V， 0 V to +5 V or ±10 V analog input ranges. The interface is designed for an efficient transfer of data while requiring a low number of interconnects. The AD974 is comprehensively tested for ac parameters such as SNR and THD， as well as the more traditional parameters of offset， gain and linearity. The AD974 is fabricated on Analog Devices’ BiCMOS process， which has high performance bipolar devices along with CMOS transistors. The AD974 is available in 28-lead DIP， SOIC and SSOP packages.