The AD7304/AD73051 are quad， 8-bit DACs that operate from a single +3 V to +5 V supply， or ±5 V supplies. The AD7304 has a serial interface， while the AD7305 has a parallel interface. Internal precision buffers swing rail-to-rail. The reference input range includes both supply rails， allowing for positive or negative full-scale output voltages. Operation is guaranteed over the supply voltage range of 2.7 V to 5.5 V， consuming less than 9 mW from a 3 V supply. The full-scale voltage output is determined by the external reference input voltage applied. The rail-to-rail VREF input to DAC VOUT allows for a full-scale voltage set equal to the positive supply， VDD， the negative supply， VSS， or any value in between. The AD7304’s doubled-buffered serial data interface offers high speed， 3-wire， SPI?-， and microcontroller-compatible inputs using data in （SDI）， clock （CLK）， and chip select （CS） pins. Additionally， an internal power-on reset sets the output to zero scale. The parallel input AD7305 uses a standard address decode along with the WR control line to load data into the input registers. The double-buffered architecture allows all four input registers to be preloaded with new values， followed by an LDAC control strobe that copies all the new data into the DAC registers， thereby updating the analog output values.