AD7871JN

Overview

The AD7871JN is a complete monolithic 14-bit analog-to-digital converter (ADC) fabricated in LC2MOS technology. It operates from ±5 V power supplies and accepts bipolar input signals within a ±3 V range. The device integrates a track-and-hold amplifier, successive approximation ADC, and a 3 V buried Zener reference. It supports parallel, byte, and serial digital interfaces with an internal laser-trimmed clock or external TTL-compatible clock input. Key performance metrics include an 80 dB signal-to-noise ratio at a 10 kHz input frequency, a maximum throughput rate of 83 kSPS, and typical power dissipation of 50 mW.

Feature Summary

• Integrates a high-speed track-and-hold amplifier capable of acquiring signals to 14-bit accuracy in under 2 μs.
• Features a versatile interface logic supporting single 14-bit parallel words, two 8-bit bytes, or a 14-bit serial data stream.
• Contains a self-contained, laser-trimmed internal clock oscillator that eliminates the need for external timing components.
• Includes a factory-trimmed 3 V temperature-compensated buried Zener reference with decoupling point.

Applications

• Digital signal processing systems
• High speed modems
• Speech recognition and synthesis equipment
• Spectrum analysis instruments
• DSP servo control loops

Procurement Notes

Verify the specific suffix J against the manufacturer's ordering guide to confirm the commercial temperature range of 0°C to +70°C. Ensure the package type matches the required footprint, as the AD7871 is available in multiple configurations including PDIP-28, PLCC-28, and CERDIP-28. Confirm pinout compatibility if replacing older revisions.

Selection Notes

Select the AD7871 when a single-channel 14-bit resolution is required with flexible data output formats. Choose this component over the AD7872 if parallel or byte-mode interfacing is necessary, as the AD7872 is restricted to serial output only. Consider the internal clock capability for designs minimizing external component count.

Part Context

The AD7871 belongs to the AD7871/AD7872 family of fast, complete 14-bit sampling ADCs. These devices are designed for applications requiring dynamic performance specifications such as distortion and SNR. The series utilizes Analog Devices' LC2MOS mixed technology process to achieve low power consumption while maintaining high conversion speeds.

Replacement Considerations

The AD7872 serves as a functional substitute if serial-only output is acceptable. Verify that the replacement part number matches the required package style and temperature grade. Check for any changes in pin configuration or interface requirements between revisions.