The DAC9881 is an 18-bit, single-channel, voltage-output digital-to-analog converter (DAC). The device features 18-bit monotonicity, excellent linearity, very low-noise, and fast settling time. The on-chip precision output amplifier allows for a rail-to-rail output swing to be achieved over the full supply range of 2.7 V to 5.5 V. The device supports a standard serial peripheral interface (SPI) capable of operating with input data clock frequencies of up to 50 MHz. The DAC9881 requires an external reference voltage to set the output range of the DAC channel. A programmable power-on reset circuit is also incorporated into the device to make sure that the DAC output powers up at zero-scale or midscale, and remains there until a valid write command. Additionally, the DAC9881 has the capability to function in either unipolar straight binary or two’s complement mode. The DAC9881 provides low-power operation. To further save energy, power-down mode can be achieved by accessing the PDN pin, thereby reducing the current consumption to 25 µA at 5 V. Power consumption is 4 mW at 5 V, reducing to 125 µW in power-down mode.