The AD5627R/AD5647R/AD5667R， AD5627/AD5667 members of the nanoDAC family are low power， dual， 12-， 14-， 16-bit buffered voltage-out digital-to-analog converters （DACs） with/without on-chip reference. All devices operate from a single 2.7 V to 5.5 V supply， are guaranteed monotonic by design， and have an I2 C-compatible serial interface. The AD5627R/AD5647R/AD5667R have an on-chip reference. The AD5627RBCPZ， AD5647RBCPZ， and AD5667RBCPZ have a 1.25 V， 5 ppm/°C reference， giving a full-scale output range of 2.5 V; the AD5627RBRMZ and AD5667RBRMZ have a 2.5 V， 5 ppm/°C reference， giving a full-scale output range of 5 V. The on-chip reference is off at power-up， allowing the use of an external reference. The internal reference is enabled via a software write. The AD5667 and AD5627 require an external reference voltage to set the output range of the DAC. The AD5627R/AD5647R/AD5667R， AD5627/AD5667 incorporate a power-on reset circuit that ensures the DAC output powers up to 0 V， and remains there until a valid write takes place.