Transistors - Bipolar (BJT) - Single, Pre-Biased

Part Number	Description / PDF	Quantity
RN2111MFV,L3F Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A VESM	0
RN1415,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	6000
RN1316,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A USM	9060
RN2307,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A USM	3300
RN2108,LF(CT Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A SSM	2900
RN1415(TE85L,F) Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	1745
RN2404,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A SMINI	0
RN1418(TE85L,F) Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	1102
RN1416,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	300
RN2106,LF(CT Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A SSM	5690
RN2405,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A SMINI	0
RN1413(TE85L,F) Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	5675
RN1116,LF(CT Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SSM	3000
RN1308,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A USM	7466
RN1418,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	5996
RN1406,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	3000
RN2113,LF(CT Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS PNP 50V 0.1A SSM	6000
RN1131MFV(TL3,T) Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A VESM	3000
RN1317(TE85L,F) Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A USM	0
RN1405,LF Toshiba Electronic Devices and Storage Corporation	TRANS PREBIAS NPN 50V 0.1A SMINI	0

Transistors - Bipolar (BJT) - Single, Pre-Biased

1. Overview

Pre-biased bipolar junction transistors (BJTs) are discrete semiconductor devices with integrated biasing resistors, designed to simplify circuit design and improve operational stability. Unlike standard BJTs requiring external biasing components, pre-biased BJTs incorporate internal resistors to set the base-emitter voltage and collector current. These devices are critical in modern electronics for applications demanding compact design, consistent performance, and reduced component count. Their ability to maintain stable operation under varying temperature and voltage conditions makes them essential in consumer electronics, industrial automation, and automotive systems.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
NPN Pre-Biased BJT	Positive bias resistor network, low-side switching	Logic-level switching, LED drivers
PNP Pre-Biased BJT	Negative bias resistor network, high-side switching	Power supply control, relay drivers
Digital Transistor	Integrated resistors with ESD protection	Digital logic circuits, portable devices

3. Structure and Composition

Pre-biased BJTs consist of a silicon semiconductor die with three doped regions (emitter, base, collector) forming two p-n junctions. The key structural elements include: - Monolithic Resistor Network: Thin-film or diffused resistors embedded in the die for fixed biasing - Metal Contacts: Aluminum or copper layers for external connections - Encapsulation: Plastic or ceramic packaging with standard pinouts (e.g., SOT-23, TO-92) - Passivation Layer: Silicon dioxide/nitride coating to prevent surface contamination

4. Key Technical Specifications

Parameter	Description	Importance
Current Gain (hFE)	Ratio of collector to base current	Determines amplification capability
Max Collector Voltage (VCEO)	Max voltage across collector-emitter	Defines operating voltage range
Transition Frequency (fT)	Frequency response limit	Critical for RF and switching applications
Power Dissipation (Ptot)	Max thermal power handling	Dictates thermal management needs
Built-in Resistor Ratio (R1/R2)	Internal resistor division ratio	Controls bias point stability

5. Application Areas

Main industries and typical equipment: - Consumer Electronics: Mobile phone chargers, wearable devices - Industrial Automation: PLC modules, motor drivers - Automotive: Sensor interfaces, LED lighting systems - Telecommunications: Base station power amplifiers - Power Management: DC-DC converter switches

6. Leading Manufacturers and Products

Manufacturer	Key Products	Features
ON Semiconductor	MMBT3904L	200mA NPN transistor with 47k bias resistors
Toshiba	2SB1958	PNP device with built-in 10k /4.7k resistor network
STMicroelectronics	SM6T120N	Automotive-grade digital transistor with ESD protection

7. Selection Guidelines

Key considerations: - Match hFE with required amplification/saturation characteristics - Confirm VCEO rating exceeds circuit voltage requirements - Select resistor ratios for desired bias point (e.g., R1=10k , R2=22k for mid-range bias) - Prioritize thermal performance in high-power applications - Consider package type (SMD vs. through-hole) for PCB constraints

8. Industry Trends

Emerging trends include: - Miniaturization: Development of 0.4mm pitch WLCSP packages - Integrated protection: ESD/clamp diodes in standard designs - High-frequency variants: fT > 5GHz for 5G infrastructure - Automotive qualification: Increased demand for AEC-Q101 certified devices - Green manufacturing: Lead-free packaging and low-toxicity materials