S-452T

Overview

The Semitec S-452T is a surface-mount current regulating diode (CRD) designed to maintain a constant current flow despite voltage fluctuations. It operates within a wide voltage range from less than 1V to 100V, ensuring stable performance regardless of load resistance changes or ripple voltage. The device features a rated power of 500mW and a maximum peak operating voltage of 100V. Its nominal pinch-off current is 4.5mA, with a limiting current ratio of 1.1 max. The component supports an operating temperature range of -40°C to +150°C and utilizes a 2-SMD flat lead package.

Feature Summary

• Maintains constant current supply over a wide voltage range without requiring multiple components for circuit implementation
• Provides stable operation independent of applied voltage fluctuations, load resistance variations, and ripple voltage
• Designed for surface-mount installation with high thermal stability across a broad temperature spectrum

Applications

• Constant current source for LED brightness stabilization in street lights and downlights
• Battery charge and discharge circuits
• Current source for proximity sensors and other electronic sensors
• Telecommunications line interface applications

Procurement Notes

Verify the specific ordering suffix against official documentation to confirm packaging type and taping specifications. Confirm that the selected variant matches the required surface-mount configuration and pinout orientation. Ensure compliance with RoHS3 standards if environmental regulations apply to the assembly process. Cross-reference the manufacturer part number with distributor catalogs to validate availability and authenticity before procurement.

Selection Notes

Select the S-452T when a precise 4.5mA constant current is required in a compact surface-mount form factor. Consider the 500mW power rating and 100V voltage limit during circuit design to ensure safe operating margins. Evaluate the temperature coefficient characteristics if the application involves significant ambient temperature variations. Compare against axial-leaded alternatives only if surface-mount constraints are not present.

Part Context

The S-452T belongs to the Semitec S series of current regulating diodes, which are optimized for surface-mount technology. This series shares functional similarities with the E series but differs in packaging and power ratings. The S series typically offers higher power dissipation capabilities compared to the axial-leaded E series variants, making it suitable for dense PCB layouts where thermal management is critical.

Replacement Considerations

Direct replacements include other Semitec S-series CRDs with similar current ratings, such as the S-352T or S-562T, depending on specific current tolerance requirements. Verify that any substitute maintains the same 2-SMD flat lead package dimensions and cathode marking orientation to ensure mechanical compatibility.