AD7669

The AD7569/AD7669 is a complete, 8-bit, analog I/O systemon a single monolithic chip. The AD7569 contains a high speedsuccessive approximation ADC with 2 s conversion time, a track/hold with 200 kHz bandwidth, a DAC and an output buffer ampli-fier with 1 s settling time. A temperature-compensated 1.25 Vbandgap reference provides a precision reference voltage for theADC and the DAC. The AD7669 is similar, but contains twoDACs with output buffer amplifiers.

A choice of analog input/output ranges is available. Using a sup-ply voltage of +5 V, input and output ranges of zero to 1.25 Vand zero to 2.5 volts may be programmed using the RANGE in-put pin. Using a ±5 V supply, bipolar ranges of ±1.25 V or±2.5 V may be programmed.

Digital interfacing is via an 8-bit I/O port and standard micro-processor control lines. Bus interface timing is extremely fast, al-lowing easy connection to all popular 8-bit microprocessors. Aseparate start convert line controls the track/hold and ADC togive precise control of the sampling period.

The AD7569/AD7669 is fabricated in Linear-CompatibleCMOS (LC²MOS), an advanced, mixed technology processcombining precision bipolar circuits with low power CMOSlogic. The AD7569 is packaged in a 24-pin, 0.3" wide "skinny"DIP, a 24-terminal SOIC and 28-terminal PLCC and LCCCpackages. The AD7669 is available in a 28-pin, 0.6" plasticDIP, 28-terminal SOIC and 28-terminal PLCC package.