AD7870KP

Overview

The AD7870KP is a monolithic 12-bit successive approximation analog-to-digital converter manufactured by Analog Devices. It integrates a track-and-hold amplifier, an internal laser-trimmed clock, and a 3 V buried Zener reference. The device operates from ±5 V power supplies and accepts a single-ended analog input range of ±3 V. It supports parallel, byte, and serial digital interfaces with a typical data access time of 57 ns. Key performance metrics include a signal-to-noise ratio of 72 dB at a 10 kHz input frequency, a conversion time of 8 μs, and a maximum throughput rate of 100 kS/s. Power dissipation is typically 60 mW.

Feature Summary

• Integrates a complete 12-bit ADC with a 2 μs track-and-hold amplifier and on-chip reference.
• Features a versatile digital interface supporting parallel, byte, and serial data output formats.
• Includes a self-contained internal clock that is laser-trimmed for accurate conversion timing.
• Provides fast microprocessor interfacing with standard control inputs and low data access times.

Applications

• Data acquisition systems requiring high-speed sampling
• Digital signal processing (DSP) applications
• Industrial process control instrumentation

Procurement Notes

Verify the specific suffix K against the manufacturer's current ordering guide to confirm temperature range and package compliance. Ensure the component matches the required ±3 V input range and ±5 V supply specifications. Confirm RoHS status and lead finish details directly from the official datasheet or authorized distributor documentation before procurement.

Selection Notes

Select the AD7870KP when a single-channel, 12-bit resolution is required with a bipolar ±3 V input range. This part is suitable for designs needing integrated reference and clock functions to minimize external components. Compare dynamic performance specifications such as SNR and THD against system requirements. Ensure the PLCC-28 package format fits the PCB layout constraints.

Part Context

The AD7870 is part of the AD7870/AD7875/AD7876 family of complete 12-bit sampling ADCs. While sharing similar architecture and interface logic, the AD7870 is distinguished by its ±3 V analog input range, whereas the AD7875 uses 0 V to +5 V and the AD7876 uses ±10 V. All variants in this series offer comparable conversion speeds and power consumption characteristics.

Replacement Considerations

Direct pin-compatible replacements within the same family include the AD7875 and AD7876, provided the input voltage range differences are accommodated in the circuit design. Other 12-bit SAR ADCs may require significant schematic and software modifications due to differing interface protocols or pinouts.