AD9714BCPZRL7

Data Acquisition - Digital to Analog Converters (DAC)

The AD9714BCPZRL7 is a monolithic integrated circuit used as a digital-to-analog converter (DAC). It provides 8-bit resolution and operates from a single 3.3V power supply. The device supports a differential voltage reference input, allowing the output level to be adjusted via external resistors. The DAC also features an integrated precision output amplifier with four selectable gains of +1.3, +3.9, +6.5 and +9.1 V/V.

The AD9714BCPZRL7 is intended for PC audio input and output interfaces and similar applications. It can also be used in active filter design and signal conditioning. The DAC\'s integrated output amplifier offers stable gain and temperature coefficient, allowing it to maintain its performance level even over a wide temperature range (-40 to +125 degrees C). It also offers low noise levels and high signal fidelity, along with an improved signal-to-noise ratio.

The AD9714BCPZRL7 features a slew rate of up to 16 V/us on the +1.3V/V full-scale setting. It also offers a wide operating range of digital input voltages, from 0.7V to 3.3V. With an automatic power-down function, the DAC can be disabled to save power when it is not needed. The device is capable of fast settling time to less than 1us if the output voltage is changed quickly.

Working Principle

The AD9714BCPZRL7 is a voltage-output DAC that acquires an 8-bit digital word and converts it into an analog voltage output. It has a differential current source that is switched on and off in such a way that the analog output voltage will be equal to the digital input. In the case of AD9714BCPZRL7, the digital inputs are in NRZ (non-return-to-zero) format.

The current source consists of two PMOS transistor switches driven by a differential current mirror. The digital information is encoded into the gates of these transistors. At any given moment, one transistor will be on and will draw current, while the other will be off and will not draw current. Depending on the voltage being applied to the digital inputs, one of the two transistors will draw more current than the other and hence create a differential current which determines the analog voltage output.

The integrated output amplifier helps to maintain a stable output voltage, irrespective of the load applied or temperature changes. The amplifier has four selectable gain levels. When the gain is set to +9.1V/V, the amplifier will output a voltage equal to the voltage applied to the differential reference input. When the gain is set to any other level, the output voltage will be equal to the reference voltage multiplied by the selected gain.

To achieve higher accuracy, the AD9714BCPZRL7 includes an internal oscillator that helps to eliminate the effects of jitter and ensure a stable output voltage. The device also features an ‘auto zero’ circuitry that compensates for any offset voltages in the DAC channels. This helps to enhance the accuracy and linearity of the DAC outputs.

Conclusion

The AD9714BCPZRL7 is a monolithic digital-to-analog converter designed for demanding PC audio input and output interfaces. It features 8-bit resolution, programmable gain, low noise and low distortion. The integrated output amplifier ensures stable output voltage irrespective of the load and temperature changes. The ‘auto zero’ circuitry and an internal oscillator further help to keep the DAC\'s performance at a high level.