AD7868

a FEATURES Complete 12-Bit I/O System, Comprising: 12-Bit ADC with Track/Hold Amplifier 83 kHz Throughout Rate 72 dB SNR 12-Bit DAC with Output Amplifier 3 ␮ s Settling Time 72 dB SNR On-Chip Voltage Reference Operates from ؎ 5 V Supplies Low Power – 130 mW typ Small 0.3" Wide DIP APPLICATIONS Digital Signal Processing Speech Recognition and Synthesis Spectrum Analysis High Speed Modems DSP Servo Control LC2MOS Complete, 12-Bit Analog I/O System AD7868 FUNCTIONAL BLOCK DIAGRAM VDD RI DAC R R LDAC TFS TCLK DT CONTROL RFS RCLK DR CLK CONVST CLOCK 12-BIT DAC DAC 3V REFERENCE ADC 3V REFERENCE ADC SERIAL INTERFACE R 12-BIT ADC R VOUT DAC SERIAL INTERFACE RO DAC RO ADC VIN TRACK/HOLD AD7868 GENERAL DESCRIPTION DGND VSS AGND The AD7868 is a complete 12-bit I/O system containing a DAC and an ADC . The ADC is a successive approximation type with a track-and-hold amplifier having a combined throughput rate of 83 kHz. The DAC has an output buffer amplifier with a settling time of 3 µs to 12 bits. Temperature compensated 3 V buried Zener references provide precision references for the DAC and ADC. Interfacing to both the DAC and ADC is serial, minimizing pin count and giving a small 24-pin package size. Standard control signals allow serial interfacing to most DSP machines. Asynchronous ADC conversion control and DAC updating is made possible with the CONVST and LDAC logic inputs. The AD7868 operates from ± 5 V power supplies, the analog input/output range of the ADC/DAC is...