3656BG

Overview

The Texas Instruments 3656BG is a transformer-coupled isolation amplifier providing complete signal and power isolation in integrated circuit form. It features three-port isolation with an internal isolated power supply. The device offers a 30 kHz small-signal bandwidth, 125 dB common-mode rejection at 60Hz, and an initial gain accuracy of 0.3%. It operates within a temperature range of -25°C to +85°C and utilizes a 20-lead ceramic DIP package.

Feature Summary

• Provides total galvanic isolation for both signal transmission and power delivery via a miniature hybrid transformer.
• Supports three completely independent ground references for enhanced system flexibility.
• Generates internal isolated power available to energize external input or output circuitry.

Applications

• Medical patient monitoring and diagnostic instrumentation
• Industrial ground loop elimination and off-ground signal measurement
• Nuclear input/output and power isolation systems

Procurement Notes

Verify the specific suffix BG against official datasheets to confirm the precise gain accuracy and temperature coefficient specifications. Ensure compatibility with the required 20-lead ceramic DIP package dimensions. Confirm that the component meets all necessary regulatory standards for the intended application environment before procurement.

Selection Notes

Select this component when high-voltage isolation between input, output, and power domains is required. It is suitable for applications demanding low leakage current and high common-mode rejection. Consider the internal power generation capability if external isolated supplies are unavailable or undesirable for system complexity reduction.

Part Context

The 3656 series represents a pioneering analog signal processing solution by integrating modulation and demodulation techniques into a single chip. Originally developed by Burr-Brown Corporation, this technology enables robust isolation without the need for discrete transformer components, establishing a standard for high-performance isolation amplifiers.

Replacement Considerations

Consult official manufacturer documentation for confirmed substitute part numbers. Verify pinout compatibility and electrical parameter equivalence before implementation.