UNR521100L

Overview

The UNR521L is a Silicon NPN epitaxial planar transistor with built-in bias resistors, designed for digital circuits. It features an S-Mini (SC-70) package with three terminals: Base, Emitter, and Collector. The device has a maximum collector-emitter voltage of 50 V and a continuous collector current rating of 100 mA at 25°C. Total power dissipation is limited to 150 mW. The internal resistor configuration consists of R1 = 4.7 kΩ and R2 = 4.7 kΩ, resulting in a nominal resistance ratio of 1.0. The minimum forward current transfer ratio (hFE) is specified as 60 under standard test conditions.

Feature Summary

• Integrates two resistors into a single compact package to reduce component count and board space.
• Supports automatic insertion via tape packing and magazine packing configurations.
• Provides standardized biasing characteristics suitable for direct logic interface applications.

Applications

• Digital switching circuits
• Logic level translation interfaces
• General-purpose electronic equipment

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact resistance values and hFE ranking. Confirm RoHS compliance status and lifecycle stage, as maintenance or discontinuation notices may apply. Ensure the SC-70 package dimensions match the target PCB footprint requirements before finalizing procurement.

Selection Notes

Select this component when a fixed 1:1 bias resistor ratio is required for NPN switching applications. Verify that the 100 mA collector current limit meets the load requirements. Check the hFE minimum specification to ensure adequate drive capability for the intended logic family. Consider the 150 mW power dissipation limit relative to ambient temperature derating curves.

Part Context

This part belongs to the Panasonic UNR521x series of transistors with built-in resistors. The series offers various resistor combinations and gain rankings within the same physical package. The 'L' suffix specifically denotes the 4.7 kΩ / 4.7 kΩ resistor configuration. This series is designed to replace discrete transistor and resistor networks in digital logic designs.

Replacement Considerations

Cross-reference with other manufacturers' SOT-323 or SC-70 packaged NPN digital transistors featuring dual bias resistors. Ensure equivalent VCEO, IC, and PT ratings are met. Verify that the replacement part offers compatible R1/R2 values and hFE ranges to maintain circuit performance without modification.

FAQ

What are the specific values of the built-in resistors for the UNR521L?

The UNR521L contains two built-in resistors, R1 and R2, both with a nominal value of 4.7 kΩ.

What is the maximum collector current allowed for this device?

The absolute maximum rating for the collector current (IC) is 100 mA at an ambient temperature of 25°C.

Is the UNR521L compliant with RoHS directives?

Yes, the datasheet states that this product complies with the RoHS Directive (EU 2002/95/EC).