System Ready, 18-Bit ±1 LSB INL, Voltage Output DAC

The AD5780 is a true 18-bit, unbuffered voltage output digitalto-analog converter (DAC) that operates from a bipolar supply of up to 33 V. The AD5780 accepts a positive reference input range of 5 V to VDD − 2.5 V and a negative reference input range of VSS + 2.5 V to 0 V. Both reference inputs are buffered on chip and external buffers are not required. The AD5780 offers a relative accuracy specification of ±1 LSB maximum range, and operation is guaranteed monotonic with a ±1 LSB differential nonlinearity (DNL) maximum range specification.

The part uses a versatile 3-wire serial interface that operates at clock rates of up to 35 MHz and is compatible with standard serial peripheral interface (SPI), QSPI™, MICROWIRE™, and DSP interface standards. The part incorporates a power-on reset circuit that ensures that the DAC output powers up to 0 V 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.

Product Highlights

* True 18-bit accuracy.

* Wide power supply range of up to ±16.5 V.

* −40°C to +125°C operating temperature range.

* Low 8 nV/√Hz noise.

* Low ±0.018 ppm/°C gain error temperature coefficient.

Applications

* Medical instrumentation

* Test and measurement

* Industrial control

* Scientific and aerospace instrumentation

* Data acquisition systems

* Digital gain and offset adjustment

* Power supply control

* True 18-bit voltage output DAC, ±1 LSB INL

* 8 nV/√Hz output noise spectral density

* 0.025 LSB long-term linearity error stability

* ±0.018 ppm/°C gain error temperature coefficient

* 2.5 µs output voltage settling time

* 3.5 nV-sec midscale glitch impulse

* Integrated precision reference buffers

* Operating temperature range: −40°C to +125°C

* 4 mm × 5 mm LFCSP package

* Wide power supply range of up to ±16.5 V

* 35 MHz Schmitt triggered digital interface

* 1.8 V-compatible digital interface