RN1405,LF

Overview

The RN1405,LF is a single NPN pre-biased bipolar junction transistor (BJT) manufactured by Toshiba Semiconductor and Storage. It integrates bias resistors within a compact S-Mini (SOT-23) surface-mount package to reduce component count. Key electrical parameters include a maximum collector current of 100 mA, a collector-emitter breakdown voltage of 50 V, and a transition frequency of 250 MHz. The device features a minimum DC current gain (hFE) of 50 at 10 mA and 5 V, with a maximum saturation voltage of 300 mV at 250 µA base current and 5 mA collector current. Internal resistances are specified as R1 = 47 kOhms and R2 = 47 kOhms.

Feature Summary

• Integrates dual bias resistors into a single NPN transistor unit to simplify circuit design and minimize board space.
• Provides high-speed switching capabilities with a transition frequency of 250 MHz suitable for interface applications.
• Utilizes an S-Mini (SOT-23) surface-mount package for automated assembly and compact equipment manufacturing.

Applications

• Switching circuits in general-purpose electronic devices
• Inverter circuits for logic level translation
• Interface circuits connecting microcontrollers to peripheral components

Procurement Notes

Verify the specific suffix and tape/reel configuration against the manufacturer's latest datasheet before ordering. Confirm RoHS compliance status and moisture sensitivity level requirements for your assembly process. Ensure the supplier provides authentic Toshiba Semiconductor and Storage products to avoid counterfeit components.

Selection Notes

Select this component when a single NPN pre-biased transistor with 47k/47k internal resistors is required. Compare hFE and saturation voltage specifications against load requirements. Consider the S-Mini package dimensions for PCB layout constraints relative to alternative packages like US6 or ES6.

Part Context

This part belongs to the RN14xx series of single NPN pre-biased transistors from Toshiba. It is functionally complementary to the PNP variant RN2405,LF. The series is designed to replace discrete resistor-transistor combinations, offering cost reduction and improved reliability through integrated monolithic construction.

Replacement Considerations

Direct substitutes include other manufacturers' single NPN BRTs with identical 47k/47k resistor values and SOT-23 packaging. Verify pinout compatibility and thermal characteristics before substitution. Complementary PNP versions are available in the same series family.