DS78C120J/B

Overview

The DS78C120 is a dual CMOS-compatible differential line receiver designed for balanced and unbalanced digital data transmission. It provides full compatibility with EIA standards RS-232-C, RS-422, and RS-423, as well as Federal Standards 1020, 1030, and MIL-188-114. The device operates within a supply voltage range of 4.5V to 15V and supports an input voltage range of ±15V for both differential and common-mode signals. Each receiver includes a separate strobe input for time discrimination and incorporates a 180Ω terminating resistor. The component features fail-safe mode detection and 50mV input hysteresis to ensure reliable operation in noisy environments.

Feature Summary

• Full compatibility with EIA, Federal, and MIL communication standards for robust signal reception
• Integrated 180Ω line termination resistors to minimize signal reflections on transmission lines
• Separate logic strobe inputs per receiver for precise time discrimination and noise filtering
• Fail-safe circuitry that forces outputs to a defined state upon open or shorted input faults

Applications

• Balanced digital data transmission systems requiring high noise immunity
• Unbalanced interface applications such as RS-232 and RS-423 networks
• Industrial control systems utilizing Federal Standards 1020 and 1030 protocols
• Military communication equipment adhering to MIL-188-114 specifications

Procurement Notes

Verify the obsolete status of this component before initiating any procurement actions. Confirm whether existing stock is available from authorized distributors or if surplus markets are required. Ensure that the specific package variant matches the design requirements, as manufacturing processes may vary between cavity and molded packages. Review the latest datasheet revisions to confirm pinout consistency and electrical characteristics remain unchanged.

Selection Notes

Select this component when interfacing with legacy EIA or MIL communication standards requiring differential reception. Evaluate the need for integrated line termination to simplify PCB layout and reduce external component count. Consider the operating temperature range and supply voltage flexibility to ensure compatibility with the target system environment. Verify that the strobe functionality aligns with the timing requirements of the receiving logic gates.

Part Context

Originally manufactured by Texas Instruments, this part is now distributed by Rochester Electronics, LLC. The device belongs to the DS78C series of line receivers, which are designed for high-performance data transmission. It serves as a CMOS-compatible alternative to older bipolar line receivers, offering lower power consumption while maintaining compatibility with standard TTL and CMOS logic families.

Replacement Considerations

The DS78C120 is marked as obsolete. Potential replacements include the DS7820 or other compatible dual differential line receivers from the same family. Verify pin-to-pin compatibility and electrical parameter alignment before substitution.