AD7878JN

Overview

The AD7878JN is a complete 12-bit analog-to-digital converter featuring an integrated DSP interface with an 8-word FIFO memory. It operates on dual ±5 V supplies and accepts a bipolar analog input range of ±3 V. The device provides a signal-to-noise ratio of 70 dB at a 10 kHz input frequency with a 100 kHz sampling rate. Key performance metrics include a maximum data access time of 57 ns and a typical power dissipation of 60 mW. The unit utilizes Linear Compatible CMOS technology and is housed in a 28-pin plastic DIP package.

Feature Summary

• Integrated 8-word first-in, first-out memory reduces software overhead for servicing interrupts in digital signal processors.
• On-chip track/hold amplifier and 3 V zener reference eliminate the need for external components.
• Status/control register allows programmable FIFO word count and monitoring of buffer status flags.

Applications

• Digital Signal Processing
• Speech Recognition and Synthesis
• Spectrum Analysis

Procurement Notes

Verify the specific suffix JN corresponds to the 28-pin plastic DIP package and the 0°C to +70°C operating temperature range. Confirm that the ordering part number matches the required SNR grade of 70 dB. Ensure compatibility with the specified ±5 V supply requirements before finalizing procurement.

Selection Notes

Select this component when interfacing directly with high-speed DSPs such as the ADSP-2100 or TMS320 series. The 57 ns data access time supports direct connection to modern 16-bit microprocessors. Consider the internal FIFO depth if minimizing processor interrupt latency is critical for the application architecture.

Part Context

This model belongs to the AD7878 family of LC2MOS ADCs. Variants within the family differ by operating temperature range, package style (DIP, PLCC, LCCC), and dynamic performance grades. The JN designation specifically identifies the industrial temperature grade version in a standard plastic dual-in-line package.

Replacement Considerations

The AD7878KN offers identical functionality with a higher SNR grade of 72 dB in the same package. The AD7878LN provides a faster 41 ns data access time. For extended temperature ranges, the AD7878AQ or AD7878BQ are available in ceramic packages.