AD7875KP

Overview

The AD7875KP is a complete monolithic 12-bit successive approximation analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It integrates a track-and-hold amplifier, an 8 μs ADC core, and a laser-trimmed internal reference on a single chip. The device operates from ±5 V power supplies and accepts a unipolar analog input range of 0 V to +5 V. It supports parallel, byte, and serial digital interfaces with a data access time of 57 ns. Key performance specifications include a maximum conversion time of 9 μs using the internal clock, a signal-to-noise ratio of 70 dB at 10 kHz input frequency, and typical power dissipation of 60 mW.

Feature Summary

• Integrates a 2 μs track-and-hold amplifier, 12-bit SAR ADC, and internal 3 V buried Zener reference for complete standalone operation.
• Offers versatile digital interface options including 12-bit parallel, two 8-bit byte, and serial data output formats controlled by the 12/8/CLK pin.
• Features a self-contained laser-trimmed internal clock oscillator that guarantees accurate conversion timing without external components.
• Provides fast microprocessor interfacing with a 57 ns data access time compatible with modern 8-bit and 16-bit systems.

Applications

• High-speed traditional measurement and control systems requiring multiplexed channels.
• Digital signal processing (DSP) applications utilizing dynamic performance parameters like SNR and THD.
• Microprocessor-based data acquisition systems needing fast bus access times.

Procurement Notes

Verify the specific suffix 'K' corresponds to the commercial temperature range (0°C to +70°C) as defined in the manufacturer's ordering guide. Confirm package availability matches the required footprint, as the AD7875 series is offered in DIP, PLCC, and SOIC variants. Ensure supply chain sources provide documentation verifying the component's authenticity and compliance with the specified electrical characteristics.

Selection Notes

Select the AD7875KP when a unipolar 0 V to +5 V input range is required, distinguishing it from the bipolar AD7870 (±3 V) and AD7876 (±10 V). Choose this variant over others if the commercial temperature range suffices for the application environment. Consider the integrated reference and clock features to reduce external component count compared to discrete ADC solutions.

Part Context

The AD7875KP belongs to the AD7870/AD7875/AD7876 family of complete 12-bit sampling ADCs. These devices utilize LC2MOS technology to combine high dc accuracy with high conversion rates. The family shares identical functional block diagrams and interface logic, differing primarily in analog input voltage ranges and available package types. This integration eliminates the need for separate sample-and-hold amplifiers in multi-channel systems.

Replacement Considerations

Direct replacements within the same family include the AD7870 for bipolar ±3 V inputs or the AD7876 for bipolar ±10 V inputs, provided the package and temperature grade match. Cross-family substitutes require verification of pin compatibility, interface protocols, and input voltage tolerances against the system requirements.