1N5303

Overview

The Microchip Technology 1N5303 is a current regulator diode designed for stable current control in electronic circuits. It operates with a maximum voltage of 100V and provides a regulated current of 1.76mA. The device has a maximum power dissipation of 475mW to 500mW, depending on the specific variant documentation. It utilizes a DO-7 axial through-hole package, suitable for standard PCB mounting. The component functions as a two-terminal device, maintaining constant current over a wide range of voltages.

Feature Summary

• Provides constant current regulation across varying voltage loads
• Two-terminal design simplifies circuit integration without external biasing
• Capable of operation in high-temperature environments up to 175°C junction temperature

Applications

• Biasing elements for transistors and integrated circuits
• Current limiting protection in series with sensitive components
• Constant current sources for LED driving or sensor excitation

Procurement Notes

Verify the exact suffix (e.g., -1, /TR) against the official datasheet to ensure correct packaging and qualification level. Confirm MIL-PRF-19500 compliance if military-grade reliability is required. Check RoHS status as some variants may not be compliant. Ensure the DO-7 package matches your board layout constraints before ordering.

Selection Notes

Select based on required regulated current value; the 1N5303 specifically offers 1.76mA. Ensure the operating voltage remains below the 100V maximum rating while providing sufficient headroom for regulation. Consider thermal management for the 475mW/500mW dissipation limit. Compare with adjacent part numbers like 1N5302 or 1N5304 if different current levels are needed.

Part Context

The 1N5303 belongs to the 1N53xx series of current regulator diodes manufactured by Microchip Technology. This series is widely used for simple, low-cost current stabilization. The part is often cross-referenced with older JAN or MIL-spec designations. It serves as a fundamental passive-like active component for analog circuit design.

Replacement Considerations

Direct substitutes include other 1.76mA current regulator diodes from compatible manufacturers. Verify pinout compatibility for DO-7 packages. Adjacent series members like 1N5302 (1.43mA) or 1N5304 (2.15mA) may require circuit adjustment. Ensure replacement parts meet the same voltage and power dissipation ratings.