2-Channel, 300 mA Current Source Output 16-Bit SoftSpan DAC

The AD5778R is a 2-channel, 16-bit current source digital-to-analog converter (DAC), providing two high-compliance current source outputs with a guaranteed 1 V dropout at 200 mA. The device supports load voltages of up to 32 V. There are eight current ranges, programmable per channel, with full-scale outputs of up to 300 mA. Additionally, the channels can be paralleled to allow for ultrafine adjustments of large currents or for combined outputs of up to 600 mA.

A dedicated supply pin is provided for every output channel. Each channel can be operated from 2.85 V to 33 V, and internal switches allow any output to be pulled to the optional negative supply.

The AD5778R includes a precision integrated 1.25 V reference (10 ppm/°C maximum), with the option to use an external reference.

The SPI-/Microwire-compatible 3-wire serial interface operates on logic levels as low as 1.71 V at clock rates up to 50 MHz.

APPLICATIONS

* Tunable lasers

* Semiconductor optical amplifiers

* Resistive heaters

* Current-mode biasing

* Proportional solenoid drive

* Per channel programmable output ranges: 300 mA, 200 mA, 100 mA, 50 mA, 25 mA, 12.5 mA, 6.25 mA, and 3.125 mA

* Flexible 2.85 V to 33 V supply voltage

* 1 V dropout guaranteed

* Separate voltage supply per output channel

* Internal switches to optional negative supply

* Full 16-bit resolution at all ranges