AD9281ARS

Analog To Digital Converters (ADC) Overview

The AD9281ARS is a dual-channel, 8-bit CMOS analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates at a sampling rate of 28 MSPS and features a pipeline architecture with simultaneous sampling sample-and-hold amplifiers. The device integrates two input buffer amplifiers and an internal voltage reference, eliminating the need for external op amps in most applications. It accepts single-ended or differential inputs and outputs multiplexed digital data via a parallel interface. Power consumption is 225 mW at a 3 V supply, with an operating range of 2.7 V to 5.5 V. Key performance metrics include a Signal-to-Noise Ratio (SNR) of 49.2 dB, Spurious-Free Dynamic Range (SFDR) of –65 dB, and Differential Nonlinearity (DNL) of ±0.1 LSB. It is housed in a 28-lead SSOP package.

Analog To Digital Converters (ADC) Feature Summary

• Complete dual matching ADC optimized for applications requiring close channel matching, such as I/Q channels in communications.
• Integrates on-chip analog input buffers and a compensated bandgap voltage reference, reducing external component count.
• Features a multiplexed digital output bus that interleaves data from both channels onto a single 8-bit bus to save board space.
• Supports flexible power supply operation from 2.7 V to 5.5 V with low power dissipation of 225 mW at 3 V.

Analog To Digital Converters (ADC) Applications

• I/Q demodulation and modulation in communication systems
• Narrowband and spread-spectrum channel processing
• Video signal acquisition and general-purpose data acquisition

Analog To Digital Converters (ADC) Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to ensure correct package type and temperature grade. Confirm availability status with authorized distributors, as lead times may vary. Ensure ESD precautions are observed during handling due to the sensitivity of the CMOS process. Cross-reference pin configurations with the latest datasheet revision to avoid integration errors.

Analog To Digital Converters (ADC) Selection Notes

Select this component when dual-channel synchronization and tight gain/offset matching between channels are critical. Consider the 28 MSPS sampling rate and 8-bit resolution for bandwidth requirements up to the Nyquist frequency. Evaluate the integrated reference and buffer capabilities against external component costs. Verify compatibility with the target logic family regarding the 2.7 V to 5.5 V supply range.

Analog To Digital Converters (ADC) Part Context

The AD9281 belongs to the AD9281 series of dual-channel ADCs from Analog Devices. It is pin-compatible with the AD9201, a dual 10-bit ADC, allowing for potential design upgrades without PCB layout changes. The device utilizes an advanced low-cost CMOS process. Related evaluation kits, such as the AD9281-EB, are available for system prototyping and performance verification.

Analog To Digital Converters (ADC) Replacement Considerations

The AD9280 is a related single-channel device from the same family but lacks the dual-channel matching optimization. For higher resolution needs, the AD9201 offers pin-compatible 10-bit performance. Other high-speed ADCs from Analog Devices may require significant circuit redesign due to differences in interface protocols and power requirements.

Analog To Digital Converters (ADC) FAQ

How does the AD9281 handle analog input signals?

The AD9281 integrates on-chip analog input buffers that eliminate the need for external op amps in most applications. It accepts both single-ended and differential input signals, providing flexibility in system design.

What is the function of the SELECT pin?

The SELECT pin controls the multiplexer for the digital output. When held LOW, the Q channel data is presented; when held HIGH, the I channel data is output. This allows both channels to share a single 8-bit digital output bus.

Can the AD9281 operate with different analog and digital supply voltages?

Yes, the AD9281 allows independent operation of the analog (AVDD) and digital (DVDD) supplies within the range of 2.7 V to 5.5 V, facilitating interfacing with various logic families.