Transistors - JFETs

Part Number	Description / PDF	Quantity
NTE2910 NTE Electronics, Inc.	JFET N CHANNEL SWITCH	291
MMBFJ110 Sanyo Semiconductor/ON Semiconductor	JFET N-CH 25V 0.46W 3-SSOT	8155
MMBF4392LT1G Sanyo Semiconductor/ON Semiconductor	JFET N-CH 30V 0.225W SOT23-3	20613
J110RLRAG	SMALL SIGNAL N-CHANNEL MOSFET	21443
J175	SMALL SIGNAL P-CHANNEL MOSFET	0
2N4858A Central Semiconductor	JFET N-CH 40V 0.36W TO-18	1798
NSVJ3910SB3T1G Sanyo Semiconductor/ON Semiconductor	IC JFET N-CH 25V 50MA 3CPH	0
MMBF5457 Sanyo Semiconductor/ON Semiconductor	JFET N-CH 25V 350MW SOT23	0
TF414T5G Sanyo Semiconductor/ON Semiconductor	JFET N-CH 40V SOT883	23027
TF252TH-4-TL-H	SMALL SIGNAL N-CHANNEL MOSFET	343211
175DFN 8L Linear Integrated Systems, Inc.	P-CHANNEL, SINGLE, JFET SWITCH	1958
TF412ST5G	N-CHANNEL JFET, 30 V, 1.2 TO 3.0	66965
CMPF4391 TR TIN/LEAD Central Semiconductor	JFET N-CH 40V 50MA SOT23	213000
2SK11030QL Panasonic	JFET N-CH 20MA 150MW MINI-3	2842
NTE461 NTE Electronics, Inc.	JFET-MATCHED DUAL N-CH	364
NTE469 NTE Electronics, Inc.	JFET-N-CHANNEL SWITCH	56
MMBFJ270 Sanyo Semiconductor/ON Semiconductor	JFET P-CH 30V 0.225W SOT23	1470615000
JANTX2N4416AUB Microsemi	JFET N-CH 35V 0.3W 4SMD	5
2SK208-O(TE85L,F) Toshiba Electronic Devices and Storage Corporation	JFET N-CH 50V SC59	8714
LS320 SOT-23 3L Linear Integrated Systems, Inc.	BIFET AMPLIFIER - HIGH INPUT Z A	14944

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