AD7870KPZ

Overview

The AD7870KPZ is a complete monolithic 12-bit analog-to-digital converter manufactured by Analog Devices Inc. It features an internal track-and-hold amplifier with a 2 μs acquisition time and an 8 μs successive approximation ADC core. The device operates from ±5 V power supplies and accepts a single-ended analog input range of ±3 V. It integrates a laser-trimmed 3 V buried Zener reference and offers parallel, byte, and serial digital interface options. Key performance metrics include a typical signal-to-noise ratio of 72 dB at a 10 kHz input frequency and a data access time of 57 ns. The component is housed in a 28-pin plastic leaded chip carrier (PLCC) package.

Feature Summary

• Integrates a 12-bit SAR ADC with a high-speed track-and-hold amplifier and an on-chip temperature-compensated reference.
• Provides versatile digital interfacing through selectable parallel, two-byte, or serial output formats compatible with standard microprocessors.
• Features a self-contained laser-trimmed clock oscillator that eliminates the need for external timing components.

Applications

• Data acquisition systems requiring fast throughput and high accuracy.
• Digital signal processing (DSP) applications utilizing dynamic performance specifications.
• Industrial control systems interfacing with modern 8-bit and 16-bit microprocessors.

Procurement Notes

Verify the specific suffix 'K' against the manufacturer's ordering guide to confirm the commercial temperature range and pin compatibility. Ensure the PLCC-28 footprint matches the design schematic. Confirm RoHS compliance status for the specific manufacturing lot prior to integration into production assemblies.

Selection Notes

Select this model when a ±3 V input range is required alongside a 12-bit resolution. Compare the 72 dB SNR specification against system noise requirements. Verify that the 57 ns data access time meets the timing constraints of the host processor bus architecture.

Part Context

This component belongs to the AD7870/AD7875/AD7876 family of LC2MOS sampling ADCs. While sharing the same core architecture and interface logic, the AD7870 is distinguished by its bipolar ±3 V input capability, whereas other family members support unipolar or wider bipolar ranges.

Replacement Considerations

The AD7870JNZ serves as a direct replacement within the same package type but may differ in integral nonlinearity specifications. Cross-reference the specific grade suffixes to ensure functional equivalence regarding linearity and offset errors.