Transistors - JFETs

Part Number	Description / PDF	Quantity
LS26VNS DFN 8L Linear Integrated Systems, Inc.	SINGLE N-CHANNEL JFET, VOLTAGE C	14180
2SK2145-BL(TE85L,F Toshiba Electronic Devices and Storage Corporation	JFET N-CH 50V SMV	4913
PN4118	SMALL SIGNAL N-CHANNEL MOSFET	17205
MCH5908H-TL-E Sanyo Semiconductor/ON Semiconductor	JFET 2N-CH 0.3W MCPH5	1837
2SK932-24-TB-E Sanyo Semiconductor/ON Semiconductor	JFET N-CH 50MA 200MW CP	1629
TF202THC-4-TL-H	SMALL SIGNAL N-CHANNEL JFET	102479
2SK715W-AC	SMALL SIGNAL FET	54289
2SK715U-AC	SMALL SIGNAL FET	45281
NSVJ2394SA3T1G Sanyo Semiconductor/ON Semiconductor	IC JFET N-CH LNA SC59-3	0
TF208TH-4-TL-H	JFET N-CH 1MA 100MW VTFP	704000
NTE312 NTE Electronics, Inc.	JFET-N-CH VHF AMP/MIX	211
MCH3914-8-TL-H Sanyo Semiconductor/ON Semiconductor	JFET N-CH 50MA 300MW MCPH3	66351000
LS5301 TO-18 3L Linear Integrated Systems, Inc.	HIGH IMPEDANCE, SINGLE, N-CHANNE	100
MMBF4119	N-CHANNEL JFET	279707
J176-D74Z Sanyo Semiconductor/ON Semiconductor	JFET P-CH 30V 0.35W TO92	405944000
MMBFJ176 Sanyo Semiconductor/ON Semiconductor	JFET P-CH 30V 0.225W SOT23-3	37741
2SK2394-7-TB-E Sanyo Semiconductor/ON Semiconductor	JFET N-CH 50MA 200MW 3CP	311512000
MMBF5484LT1G	SMALL SIGNAL N-CHANNEL MOSFET	70875
CPH3910-TL-E Sanyo Semiconductor/ON Semiconductor	JFET N-CH 25V 50MA 3CPH	40108
JANTX2N4093UB Microsemi	JFET N-CH 40V 0.36W SMD	118

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