The AD5680， a member of the nanoDAC family， is a single， 18-bit buffered voltage-out digital-to-analog converter （DAC） that operates from a single 4.5 V to 5.5 V supply and is 18-bit monotonic. The AD5680 requires an external reference voltage to set the output range of the DAC. The part incorporates a power-on reset circuit that ensures the DAC output powers up to 0 V （AD5680-1） or to midscale （AD5680-2） and remains there until a valid write takes place. The low power consumption of this part in normal operation makes it ideally suited to portable battery-operated equipment. The power consumption is 1.6 mW at 5 V. The AD5680 on-chip precision output amplifier allows rail-torail output swing to be achieved. For remote sensing applications， the output amplifier’s inverting input is available to the user. The AD5680 uses a versatile 3-wire serial interface that operates at clock rates up to 30 MHz， and is compatible with standard SPI?， QSPI?， MICROWIRE?， and DSP interface standards.