The LTC2621IDD#PBF is a single 12-bit rail-to-rail voltage output Digital-to-analog Converter (DAC) has built-in high performance output buffers and is guaranteed monotonic. This part establish new board-density benchmarks for 12-bit DAC and advance performance standards for output drive and load regulation in single-supply voltage-output DAC. The part uses a simple SPI/MICROWIRE compatible 3-wire serial interface which can be operated at clock rates up to 50MHz. Daisy-chain capability, hardware CLR and asynchronous DAC update (LDAC) pins are included. It incorporates a power-on reset circuit. During power-up, the voltage outputs rise less than 10mV above zero scale until a valid write and update take place. The voltage outputs stay at midscale until a valid write and update take place.