CMOS, Complete 12-Bit Analog I/O System

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 packages 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 +-3 V. The part is fully specified for dynamic parameters such as signal-to-noise ratio and harmonic distortion as well as traditional dc specifications.

The part is available in a 24-pin, 0.3" wide, plastic or hermetic dual-in-line package (DIP) and in 28-pin, plastic SOIC package.

* 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 ms Settling Time

72 dB SNR

On-Chip Voltage Reference