Five-Channel, Current Output DAC with Internal Reference and SPI

The LTC2672 is a family of five-channel, 12-/16-bit current source, digital-to-analog converters (DACs) that provide five high compliance, current source outputs with guaranteed 0.6 V dropout at 200 mA. There are eight current ranges that are programmable per channel with full-scale outputs of up to 300 mA. The channels can be paralleled to allow either ultrafine adjustments of large currents or combined outputs of up to 1.5 A. A dedicated supply pin is provided for each output channel. Each channel can be operated from 2.1 V to VCC, and internal switches allow any output to be pulled to the optional negative supply. The LTC2672 includes a precision integrated 1.25 V reference (10 ppm/°C maximum (LFCSP) or 2.4 ppm/°C nominal (WLCSP)), with the option to use an external reference. The serial peripheral interface (SPI)-compatible, 3‑wire serial interface operates on logic levels as low as 1.71 V and at clock rates as high as 50 MHz.

Note that throughout this data sheet, multifunction pins, such as CS/LD, are referred to by the entire pin name or by a single function of the pin.

APPLICATIONS

* Tunable lasers

* Semiconductor optical amplifier biasing

* Resistive heaters

* Current mode biasing

* Per channel programmable output current ranges: 300 mA, 200

mA, 100 mA, 50 mA, 25 mA, 12.5 mA, 6.25 mA, and 3.125 mA

* Flexible 2.1 V to VCC output supply voltages

* Flexible single- or dual-supply operation

* 0.6 V maximum dropout voltage guaranteed

* Separate voltage supply per output channel

* Internal switches to optional negative supply

* Full 12-bit and 16-bit resolution at all ranges

* Guaranteed operation −40°C to 125°C (H-grade)