AD974

a FEATURES Fast 16-Bit ADC with 200 kSPS Throughput Four Single-Ended Analog Input Channels Single +5 V Supply Operation Input Ranges: 0 V to +4 V, 0 V to +5 V and ؎ 10 V 120 mW Max Power Dissipation Power-Down Mode 50 ␮W Choice of External or Internal 2.5 V Reference On-Chip Clock Power-Down Mode V1A V1B 4-Channel, 16-Bit, 200 kSPS Data Acquisition System AD974 FUNCTIONAL BLOCK DIAGRAM PWRD BIP CAP REF VDIG VANA REF BUFF RESISTIVE NETWORK 2.5V REFERENCE AD974 EXT/INT SWITCHED 16 CAP ADC DATACLK SERIAL INTERFACE DATA R/C CS CLOCK SYNC V2A V2B RESISTIVE NETWORK 4 TO 1 MUX + LATCH V3A V3B RESISTIVE NETWORK V4A V4B RESISTIVE NETWORK EN CONTROL LOGIC & CALIBRATION CIRCUITRY GENERAL DESCRIPTION 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 package...