KSC1730OBU

Overview

The KSC1730OBU is an NPN epitaxial silicon transistor manufactured by onsemi, formerly Fairchild Semiconductor. It features a collector-emitter voltage of 15 V and a maximum collector current of 50 mA. The device exhibits a high current gain bandwidth product (fT) ranging from 800 to 1100 MHz at 5 mA collector current. Key electrical characteristics include a DC current gain (hFE) between 40 and 240 depending on the classification grade, a collector-base breakdown voltage of 30 V, and a low output capacitance of 1.5 pF maximum. It is housed in a TO-92 package.

Feature Summary

• High current gain bandwidth product suitable for ultra-high frequency applications
• Low output capacitance for efficient signal processing
• Wide DC current gain range across multiple classification grades

Applications

• VHF tuner oscillator circuits
• UHF tuner oscillator circuits
• RF amplifier stages

Procurement Notes

Verify the manufacturer origin as onsemi or Fairchild Semiconductor when sourcing this component. Confirm the specific hFE classification grade required for the application design. Ensure the TO-92 through-hole package matches the PCB footprint requirements. Check datasheet revisions for any updates to absolute maximum ratings or electrical characteristics prior to final implementation.

Selection Notes

Select the appropriate hFE classification grade based on the required gain stability for the circuit design. Consider the 15 V collector-emitter voltage limit when designing for supply variations. The TO-92 package limits power dissipation to 250 mW, requiring thermal management considerations for continuous operation near maximum ratings.

Part Context

This component belongs to the family of small-signal NPN transistors designed for RF and audio frequency amplification. It was originally produced by Fairchild Semiconductor before the company's acquisition by onsemi. The part number suffix 'OBU' typically denotes the specific tape and reel packaging configuration used for automated assembly processes.

Replacement Considerations

Direct replacements must match the NPN polarity, TO-92 package, and similar fT and VCEO specifications. Verify pinout compatibility (Emitter, Collector, Base) with the original schematic. Cross-reference with other UHF/NPN transitors having comparable gain-bandwidth products if exact substitution is unavailable.