ICL7121

® October 1997 M ECO R T NO DED ME N FO R DES NEW S IG N ICL7121 16-Bit Multiplying Microprocessor-Compatible D/A Converter Description The ICL7121 achieves 0.003% linearity without laser trimming by combining a four quadrant multiplying DAC using thin film resistors with an on-chip PROM-controlled correction circuit. Silicon-gate CMOS circuitry keeps the power dissipation very low. Microprocessor bus interfacing is eased using standard memory WRITE cycle timing and control. The input buffer register is loaded with the 16-bit input and directly controls the output switches. The register is transparent if WR and CS are held low. The ICL7121 is designed and programmed for bipolar operation. There is an offset resistor to the output which should be connected to -V REF and an inverter on the MSB line, giving the DAC a 2’s complement bipolar transfer function. Two extra resistors are included on the chip to facilitate the reference inversion, so that only an external opamp is needed. Features 16-Bit Resolution Low Integral Linearity Error -0.003% FSR Monotonic to 16 Bits Over Full Military Temperature Range (LM Grade) Microprocessor Compatible with Buffered Inputs Bipolar Application Requires No External Resistors Output Current Settling Time 3µs Max (1µs Typ) Low Linerarity and Gain Temperature Coefficients Low Power Dissipation (25mW) Full Four-Quadrant Multiplication Low Differential Nonlinearity Error at Bipolor Zero Ordering Information PART NUMB...