| Image | Part Number | Description / PDF | Quantity | Rfq |
|---|---|---|---|---|
 |
IR (Infineon Technologies) |
POWER FIELD-EFFECT TRANSISTOR |
6902 |
|
 |
IR (Infineon Technologies) |
JFET N-CHAN 35A TO247-3 |
0 |
|
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.
| 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 |
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
| Parameter | Description | Importance |
|---|---|---|
| VGS(off) | Gate-source cutoff voltage | Determines operating voltage range |
| IDSS | Saturation drain current | Defines maximum current capability |
| gm | Transconductance | Measures amplification efficiency |
| RDS(on) | On-state resistance | Impacts power dissipation |
| fT | Transition frequency | Limits high-frequency performance |
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
| 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 |
Consider the following factors when selecting JFETs: - Application type: Audio (low noise), switching (high IDSS), or RF (high fT) - 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
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