Transistors - JFETs

Part Number	Description / PDF	Quantity
J112 Sanyo Semiconductor/ON Semiconductor	JFET N-CH 35V 625MW TO92	0
2SK3738-TL-E	N-CHANNEL JFET	48000
JFTJ105	SMALL SIGNAL N-CHANNEL MOSFET	1495
IJW120R100T1FKSA1 IR (Infineon Technologies)	POWER FIELD-EFFECT TRANSISTOR	6902
2SK715U	SMALL SIGNAL FET	19911
177DFN 8L Linear Integrated Systems, Inc.	P-CHANNEL, SINGLE, JFET SWITCH	100
NTE456 NTE Electronics, Inc.	JFET-N-CH GEN AMP/SW	152
CMPFJ176 TR Central Semiconductor	IC JFET P-CH SOT23-3	0
2N5639G	SMALL SIGNAL FET	5000
2SK879-GR(TE85L,F) Toshiba Electronic Devices and Storage Corporation	JFET N-CH 0.1W USM	3000
2SK932-22-TB-E Sanyo Semiconductor/ON Semiconductor	JFET N-CH 50MA 200MW 3CP	3000
CMPF4393 TR PBFREE Central Semiconductor	JFET N-CH 40V 50MA SOT23	1456
MMBFJ113 Sanyo Semiconductor/ON Semiconductor	JFET N-CH 35V 350MW SOT23	25776
2N2609 Roving Networks / Microchip Technology	JFETS	0
2SK932-23-TB-E Sanyo Semiconductor/ON Semiconductor	JFET N-CH 50MA 200MW 3CP	2147483647
MMBFU310LT1G Sanyo Semiconductor/ON Semiconductor	JFET N-CH 25V 0.225W SOT23-3	17831
UJ3N065080K3S UnitedSiC	650V 80 MOHM SIC JFET, G3, N-ON,	326
LSK389C TO-71 6L Linear Integrated Systems, Inc.	LOW NOISE, MONOLITHIC DUAL, N-CH	286
J112-D74Z Sanyo Semiconductor/ON Semiconductor	JFET N-CH 35V 625MW TO92	0
UJ3N120070K3S UnitedSiC	1200V 70 MOHM SIC JFET, G3, N-ON	924

Transistors - JFETs

1. Overview

Junction Field-Effect Transistors (JFETs) are three-terminal voltage-controlled semiconductor devices that regulate current flow through a conductive channel. As the first type of field-effect transistor, JFETs are characterized by high input impedance, low noise, and excellent analog signal handling capabilities. They play critical roles in modern electronics for signal amplification, switching, and impedance matching applications.

2. Main Types and Functional Classification

Type	Functional Features	Application Examples
N-channel JFET	Higher electron mobility, faster operation	Audio amplifiers, RF mixers
P-channel JFET	Complementary to N-channel, lower speed	Power switching, analog switches
Dual-gate JFET	Two control gates for improved linearity	TV tuners, communication systems
High-frequency JFET	Optimized for GHz-range performance	RF amplifiers, microwave circuits

3. Structure and Composition

JFETs consist of a semiconductor channel (typically silicon or GaAs) with source and drain contacts at each end. A reverse-biased p-n junction gate controls the channel width. Key structural elements include: - Channel: Determines current capacity and transconductance - Gate: Forms depletion region to modulate channel conductivity - Metallization layers: Provide low-resistance contacts - Passivation layer: Protects device surface from contamination

4. Key Technical Specifications

Parameter	Description	Importance
V_GS(off)	Gate-source cutoff voltage	Determines operating voltage range
I_DSS	Saturation drain current	Defines maximum current capability
g_m	Transconductance	Measures amplification efficiency
R_DS(on)	On-state resistance	Impacts power dissipation
f_T	Transition frequency	Limits high-frequency performance

5. Application Fields

Major industries utilizing JFETs include: - Audio equipment: Guitar amplifiers, microphone preamps - Test & measurement: Oscilloscopes, signal analyzers - Industrial control: Sensor interfaces, process control - Medical devices: ECG machines, diagnostic equipment - Communication systems: RF front-ends, satellite receivers

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
TI (Texas Instruments)	J111	General-purpose N-channel JFET
ON Semiconductor	2N5457	High-voltage switching applications
Infineon Technologies	BF862	Low-noise RF amplifier JFET
STMicroelectronics	STJ105	Power JFET for industrial systems

7. Selection Guidelines

Consider the following factors when selecting JFETs: - Application type: Audio (low noise), switching (high I_DSS), or RF (high f_T) - Operating conditions: Temperature range, voltage requirements - Package type: Through-hole for prototyping vs. surface-mount for mass production - Cost vs performance: Balance between specifications and budget constraints

8. Industry Trends

Emerging trends shaping JFET development include: - Development of wide-bandgap JFETs using SiC/GaN for high-power applications - Integration with CMOS technology for mixed-signal systems - Miniaturization for portable electronics - Enhanced radiation-hardened variants for aerospace applications - Growing adoption in bio-sensing and IoT edge devices