Description

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 ms 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 (LC2MOS), 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.