The AD57911 is a single 20-bit， unbuffered voltage-output DAC that operates from a bipolar supply of up to 33 V. The AD5791 accepts a positive reference input in the range 5 V to VDD ? 2.5 V and a negative reference input in the range VSS + 2.5 V to 0 V. The AD5791 offers a relative accuracy specification of ±1 LSB max， and operation is guaranteed monotonic with a ±1 LSB DNL maximum specification. The part uses a versatile 3-wire serial interface that operates at clock rates up to 35 MHz and that is compatible with standard SPI， QSPI?， MICROWIRE?， and DSP interface standards. The part incorporates a power-on reset circuit that ensures the DAC output powers up to 0 V and in a known output impedance state and remains in this state until a valid write to the device takes place. The part provides an output clamp feature that places the output in a defined load state.