AD7875KN

Overview

The AD7875KN is a complete monolithic 12-bit successive approximation analog-to-digital converter (ADC) from Analog Devices. It integrates a track-and-hold amplifier, an 8 μs ADC core, and a laser-trimmed internal clock. The device operates on ±5 V power supplies and accepts a unipolar analog input range of 0 V to +5 V. It features versatile digital interfaces supporting parallel, byte, and serial data output formats with a typical data access time of 57 ns. Power consumption is typically 60 mW. The component is housed in a 24-pin ceramic dual-in-line package (CDIP-24) and supports commercial temperature ranges.

Feature Summary

• Integrates a high-speed track-and-hold amplifier and a 12-bit SAR ADC on a single chip.
• Features a factory-laser-trimmed internal clock oscillator eliminating external timing components.
• Provides flexible data output options including 12-bit parallel, two 8-bit bytes, or serial formats.
• Includes an on-chip 3 V buried Zener reference with external scaling capabilities.

Applications

• Data acquisition systems requiring 12-bit resolution.
• Industrial process control instrumentation.
• Digital signal processing front-ends for audio or vibration analysis.
• Medical equipment and diagnostic devices.

Procurement Notes

Verify the specific suffix 'KN' corresponds to the hermetic ceramic DIP-24 package variant when sourcing. Confirm that the ordering part number matches the required military or extended temperature grade if applicable, as standard plastic variants use different suffixes. Ensure compatibility with existing board layouts designed for the 24-pin CDIP footprint.

Selection Notes

Select the AD7875KN specifically for applications requiring a unipolar 0 V to +5 V input range. Choose this model over the AD7870 or AD7876 if bipolar inputs are not needed. Verify that the system can accommodate the ±5 V dual supply requirement. Consider the 57 ns access time for microprocessor interface speed requirements.

Part Context

The AD7875KN belongs to the AD7870/AD7875/AD7876 family of LC2MOS sampling ADCs. While functionally similar regarding conversion architecture, it differs from the AD7870 (±3 V input) and AD7876 (±10 V input) by its unipolar input specification. The 'KN' suffix denotes the ceramic dual-in-line package construction.

Replacement Considerations

The AD7875BQ serves as a direct functional replacement within the same family, offering identical electrical specifications but housed in a plastic leaded chip carrier (PLCC) package instead of the ceramic DIP. Pinouts remain compatible for direct substitution if the PCB allows for PLCC footprints.