The AD7569/AD7669 is a complete， 8-bit， analog I/O system on a single monolithic chip. The AD7569 contains a high speed successive approximation ADC with 2 μs conversion time， a track/ hold with 200 kHz bandwidth， a DAC and an output buffer amplifier with 1 μs settling time. A temperature-compensated 1.25 V bandgap reference provides a precision reference voltage for the ADC and the DAC. The AD7669 is similar， but contains two DACs with output buffer amplifiers. A choice of analog input/output ranges is available. Using a supply voltage of +5 V， input and output ranges of zero to 1.25 V and zero to 2.5 volts may be programmed using the RANGE input 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 microprocessor control lines. Bus interface timing is extremely fast， allowing easy connection to all popular 8-bit microprocessors. A separate start convert line controls the track/hold and ADC to give precise control of the sampling period. The AD7569/AD7669 is fabricated in Linear-Compatible CMOS （LC2 MOS）， an advanced， mixed technology process combining precision bipolar circuits with low power CMOS logic. The AD7569 is packaged in a 24-pin， 0.3“ wide “skinny” DIP， a 24-terminal SOIC and 28-terminal PLCC and LCCC packages. The AD7669 is available in a 28-pin， 0.6” plastic DIP， 28-terminal SOIC and 28-terminal PLCC package.