AD7224:  LC²MOS 8-Bit DAC with Output Amplifiers

The AD7224 is a precision 8-bit, voltage-ouput, digital-to-analog converter with output amplifier and double buffered interface logic on a monolithic CMOS chip. No external trims are required to achieve full specified performance for the part.

The double buffered interface logic consists of two 8-bit registers- an input register and a DAC register. Only the data held in the DAC register determines the analog output of the converter. The double buffering allows simultaneous update in a system containing multiple AD7224's. Both registers may be made transparent under control of three external lines, CS, WR and LDAC. With both registers transparent, the RESET line functions like a zero override; a useful function for system calibration cycles. All logic inputs are TTL and CMOS (5V) level compatible and the control logic is speed compatible with most 8-bit microprocessors.

Specified performance is guaranteed for input reference voltages from +2V to +12.5V when using dual supplies. The part is also specified for single supply operation using a reference of +10V. The ouput amplifier is capable of developing +10V across a 2 K(Ohm) load.

The AD7224 is fabricated in an all ion-implanted high speed Linear Compatible CMOS (LC²MOS) process which has been specifically developed to allow high speed digital logic circuits and precision analog circuits to be integrated on the same chip.