The AD7304/AD7305 are quad, 8-bit DACs that operate from a single +3 V to +5 V or ±5 V supply. The AD7304 has a serial interface and the AD7305 has a parallel interface. Internal precision cushioning with rail-to-rail swing. The reference input range includes both rails to provide positive or negative full-scale output voltages. The guaranteed operating voltage range is +2.7 V, +5.5 V to ±5 V, and the power consumption is less than 9 mW from a +3 V supply. The full-scale voltage output is determined by the applied external reference input voltage. Rail-to-rail VREFInput to DAC VOUTAllows the full-scale voltage to be set to a positive supply voltage, VDD, negative supply voltage VSSor any value in between.
The AD7304's double-buffered serial data interface provides high speed, 3-wire, SPI, and microcontroller-compatible inputs using data input (SDI), clock (CLK), and chip select (CS) pins.
The AD7305 parallel input uses standard address decoding and WR control lines to load data into input registers. The double-buffered architecture allows all four input registers to preload new values and then an LDAC control strobe copies all new data into the DAC registers to update the analog output values. Operating from supplies below +5.5 V, the AD7305 is also pin compatible with the popular AD7226, an industry standard device.
At power-up, an internal power-on reset keeps both devices at zero scale. The shutdown (SHDN) function of both devices is activated by setting the SDI/SHDN pin on the AD7304 and the A0/SHDN address pin on the AD7305 to tristate, which consumes 40 μA. The AD7304/AD7305 are specified over the extended industrial temperature range of -40°C to +85°C and the automotive temperature range of -40°C to +125°C.