The AD5678 is a low power， octal， buffered voltage-output DAC with four 12-bit DACs and four 16-bit DACs in a single package. All devices operate from a single 2.7 V to 5.5 V supply and are guaranteed monotonic by design. The AD5678 has an on-chip reference with an internal gain of 2. The AD5678-1 has a 1.25 V 5 ppm/°C reference， giving a fullscale output of 2.5 V; the AD5678-2 has a 2.5 V 5 ppm/°C reference， giving a full-scale output of 5 V. The on-board reference is off at power-up， allowing the use of an external reference. The internal reference is enabled via a software write. The part incorporates a power-on reset circuit that ensures that the DAC output powers up to 0 V and remains powered up at this level until a valid write takes place. The part contains a power-down feature that reduces the current consumption of the device to 400 nA at 5 V and provides software-selectable output loads while in power-down mode for any or all DAC channels.