Transistors - JFETs

Image	Part Number	Description / PDF	Quantity	Rfq
	TF410-TL-H Sanyo Semiconductor/ON Semiconductor	JFET N-CH 1MA 30MW USFP	0
	TF262TH-5-TL-H Sanyo Semiconductor/ON Semiconductor	JFET N-CH 1MA 100MW	0
	J3A012YXS/T0BY4551 NXP Semiconductors	TRANSISTOR JFET 8PLLCC	0
	J2A020YXS/T0BY425, NXP Semiconductors	TRANSISTOR JFET 8PLLCC	0
	IJW120R070T1FKSA1 IR (Infineon Technologies)	JFET N-CHAN 35A TO247-3	0
	CP232V-CEN1308-CT Central Semiconductor	TRANS JFET N-CH AMP	0
	U290-E3 Vishay / Siliconix	JFET N-CH 30V 0.5W TO-206AC	0
	2N4391-2 Vishay / Siliconix	MOSFET N-CH 40V .1NA TO-18	0
	2N4392-E3 Vishay / Siliconix	MOSFET N-CH 40V .1NA TO-18	0
	2N4861JTXL02 Vishay / Siliconix	JFET N-CH 30V TO-206	0
	CP216-2N4856-CM Central Semiconductor	JFET N-CH SWITCH CHOPPER	0
	U431 Vishay / Siliconix	JFET DUAL P-CH 25V TO-78	0
	TF202THC-L5-TL-H Sanyo Semiconductor/ON Semiconductor	JFET N-CH 1MA 100MW	0
	J3A081GUA/T1AG8VYV NXP Semiconductors	TRANSISTOR JFET	0
	J5A080GHN/T0BG208Z NXP Semiconductors	TRANSISTOR JFET	0
	J3E145GXS/S0BGCA5J NXP Semiconductors	TRANSISTOR JFET	0
	J2A012YXY/S1AY73AJ NXP Semiconductors	TRANSISTOR JFET	0
	CP216-2N4392-WN Central Semiconductor	JFET N-CH SWITCH CHOPPER	0
	J203-18 Central Semiconductor	JFET N-CH TO-92	0
	2N4860JTXV02 Vishay / Siliconix	JFET N-CH 30V TO-206	0

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