The AD8842ARZ is a 8-bit octal CMOS Digital-to-analog Converter (DAC) provides eight general purpose digitally controlled voltage adjustment devices. The TrimDAC? capability allows replacement of the mechanical trimmer function in new designs. The AD8842 is ideal for AC or DC gain control of up to 50kHz bandwidth signals. The 4-quadrant multiplying capability is useful for signal inversion and modulation often found in video vertical deflection circuitry. A new current conveyor amplifier design performs the 4-quadrant multiplying function with a single amplifier at the output of the current steering digital-to-analog converter. This approach offers an improved constant input resistance performance versus previous voltage switched DACs used in TrimDAC circuits, eliminating the need for additional input buffer amplifiers. The DAC registers are updated from an internal serial-to-parallel shift register that is loaded from a standard 3-wire serial input digital interface.
