54LS290/BCA

Overview

The SN54LS290 is a binary and quinary decade counter belonging to the LS series of TTL logic devices. It features a dual-stage architecture comprising a divide-by-two section and a divide-by-five section, enabling flexible configuration for binary, quinary, or full decimal counting operations. The device utilizes asynchronous master reset inputs (MR1, MR2) and asynchronous preset inputs (MS1, MS2) for immediate state control. Designed for military-grade reliability, it operates across an extended temperature range from -55°C to +125°C. The component is housed in a CQCC20 ceramic chip carrier package with true outputs.

Feature Summary

• Dual-stage internal structure supporting independent divide-by-two and divide-by-five counting functions
• Asynchronous master reset and asynchronous preset capabilities for immediate state initialization
• Military-qualified construction ensuring stable operation within extreme environmental conditions
• Flexible clock input configuration allowing selection between binary and quinary modes

Applications

• High-reliability military digital timing systems requiring precise frequency division
• Avionics data processing units utilizing robust decade counting architectures
• Spacecraft telemetry equipment demanding extended temperature tolerance
• Industrial control interfaces requiring asynchronous state reset functionality

Procurement Notes

Verify the specific suffix designation against official manufacturer documentation to confirm pinout compatibility and electrical characteristics. Ensure the procurement channel provides traceable certification records consistent with military quality standards. Confirm that the delivered components match the specified ceramic package type and lead finish requirements for your assembly process.

Selection Notes

Select this component when designing systems requiring a single-chip solution for both binary and decimal counting without external gating. Consider the LS series propagation delays if high-speed switching is critical. Evaluate the thermal management requirements associated with the ceramic package in enclosed military enclosures. Verify that the asynchronous control signals align with the system's power-up sequencing requirements.

Part Context

This device belongs to the standard 54/74 series of logic integrated circuits, specifically the Low-power Schottky (LS) variant known for reduced power consumption compared to standard TTL. Rochester Electronics sustains production of these legacy components to support long-term defense and aerospace programs where redesigning around modern equivalents is not feasible.

Replacement Considerations

Direct functional substitutes include the SN54LS290J and SN54LS290FK. Verify pin compatibility before substitution. Cross-reference with SN54290 variants if standard TTL speed is acceptable instead of LS performance.