AD5781ARUZ-REEL7

Overview

The AD5781ARUZ-REEL7 is a single-channel, true 18-bit unbuffered voltage output digital-to-analog converter (DAC) manufactured by Analog Devices Inc. It operates on bipolar supplies up to ±16.5 V and features a maximum integral nonlinearity (INL) of ±0.5 LSB and differential nonlinearity (DNL) of ±0.5 LSB, ensuring monotonic operation. The device utilizes a versatile 3-wire serial interface compatible with SPI, QSPI, MICROWIRE, and DSP standards, supporting clock rates up to 35 MHz. Key electrical parameters include a 1 µs settling time, 7.5 nV/√Hz noise spectral density, and an operating temperature range from −40°C to +125°C.

Feature Summary

• True 18-bit resolution with ±0.5 LSB INL and DNL for guaranteed monotonicity
• Wide power supply range supporting up to ±16.5 V analog supplies
• Low noise performance with 7.5 nV/√Hz spectral density and <0.05 ppm/°C temperature drift
• Integrated power-on reset circuit ensuring DAC output powers up to 0 V

Applications

• Medical instrumentation
• Test and measurement equipment
• Industrial control systems
• Scientific and aerospace instrumentation
• Data acquisition systems

Procurement Notes

Verify the REEL7 suffix indicates tape-and-reel packaging when sourcing components. Confirm that the specific revision matches the required datasheet specifications. Ensure compatibility with standard SPI or QSPI host controllers. Validate that the TSSOP-20 package dimensions fit the target PCB layout constraints.

Selection Notes

Select this component for applications requiring high relative accuracy and wide dynamic range. The unbuffered voltage output requires external amplification for low-impedance driving. Verify reference voltage buffering requirements, as the DAC input impedance varies with code. Consider the 35 MHz interface speed for high-throughput data acquisition needs.

Part Context

The AD5781 belongs to a family of precision DACs including the 20-bit AD5791. Complementary devices such as the AD8676 operational amplifier are recommended for buffering the voltage reference inputs to maintain specified linearity. The EVAL-AD5781ARDZ evaluation board is available for hardware testing and development.

Replacement Considerations

The AD5791ARUZ serves as a higher-resolution alternative within the same product family. Both devices share similar interface protocols and pin configurations but differ in bit depth and linearity specifications.