AD7851ARSZ-REEL

Overview

The AD7851ARSZ-REEL is a 14-bit, high-speed serial analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates from a single 5 V power supply and supports a throughput rate of 333 kSPS in the A grade version. The device features a pseudo-differential input architecture with two selectable voltage ranges: 0 V to VREF and ±VREF/2. It incorporates self-calibration and system calibration capabilities to maintain accuracy over temperature variations. The ADC utilizes a flexible serial interface compatible with SPI, QSPI, and 8051 protocols. Typical power consumption is 60 mW in normal mode, reducing to 5 µW in power-down mode.

Feature Summary

• Integrated self-calibration and system calibration mechanisms ensure long-term accuracy and stability across operating temperatures.
• Flexible serial interface supports multiple communication protocols including SPI, QSPI, and 8051 compatibility for diverse microcontroller integration.
• Pseudo-differential input structure provides two distinct input voltage ranges to accommodate various signal conditioning requirements.
• Low power design includes a dedicated sleep mode that significantly reduces current consumption while retaining calibration data.

Applications

• Digital Signal Processing systems requiring high-resolution conversion.
• Speech recognition and synthesis hardware.
• Spectrum analysis equipment.
• DSP servo control loops.
• Instrumentation and control systems.
• High-speed modem applications.
• Automotive electronic modules.

Procurement Notes

Verify the specific grade (A or K) required for your application, as throughput rates and linearity specifications differ between versions. Confirm the package type matches your PCB footprint, as the AD7851 is available in PDIP, SOIC, and SSOP configurations. Ensure the ordering suffix corresponds to the desired reel quantity if purchasing in bulk. Check for lead-free compliance if RoHS standards are mandatory for your manufacturing process.

Selection Notes

Select the A grade version if operation at 333 kSPS within the –40°C to +85°C range is necessary. Choose the K grade for 285 kSPS operation within the 0°C to 85°C range. Both grades guarantee performance up to 125°C but at a reduced throughput of 238 kSPS. Consider the input voltage range requirements; use AMODE pin configuration to select between unipolar and bipolar inputs based on the sensor signal characteristics.

Part Context

The AD7851 belongs to the Analog Devices family of high-speed serial ADCs. It is designed for applications demanding 14-bit resolution with moderate sampling speeds. The device competes in the market for precision data acquisition systems where power efficiency and calibration accuracy are critical. It serves as a bridge between analog sensor signals and digital processing units in embedded environments.

Replacement Considerations

Direct replacements include other ADI 14-bit serial ADCs such as the AD7851AR or AD7851KR. Verify interface compatibility and pinout alignment when substituting. Cross-reference specifications for throughput and linearity to ensure the replacement meets the system's dynamic performance requirements.

FAQ

What are the two analog input voltage ranges supported by the AD7851?

The AD7851 supports a unipolar range of 0 V to VREF and a bipolar range of ±VREF/2 centered about VREF/2. The selection is controlled via the AMODE pin.

How does the AD7851 handle calibration?

The device features both self-calibration and system calibration options. It can perform autocalibration upon power-up to ensure accurate operation over time and temperature changes.

What is the typical power consumption in normal mode?

The typical power consumption in normal mode is 60 mW. In power-down mode, this drops to approximately 5 µW.