BF245A Information
The BF245A is an N-channel JFET for general-purpose amplification and switching applications. It features a low gate-source leakage current, high input impedance, and low noise characteristics, making it suitable for use in sensitive circuits such as audio amplifiers and radio-frequency applications. The BF245A is typically used in low-power circuits, offering excellent performance in both analog and digital signal processing.
BF245A Pinout
Gate (G): The gate controls the flow of current between the source and drain. It is the input terminal for the device.
Source (S): The source is the terminal where current enters the device. It is typically connected to the lower potential in the circuit.
Drain (D): The drain is the terminal through which current exits the device. It is typically connected to the higher potential in the circuit.
BF245A Symbol
BF245A Footprint
BF245A 3D Model
BF245A Specification
| Parameter | Value |
| Device Type | N-channel JFET |
| Rated Voltage | 30 V |
| Drain Current (Id) | 30 mA |
| Gate-Source Cutoff Voltage | -1.3 V |
| Current Rating | 100mA |
| Junction Capacitance | 3 pF |
| Forward Transfer Admittance | 1.5 - 5 mS (typical) |
| Thermal Resistance | 100°C/W |
| Power Dissipation | 400 mW |
| Package | TO-92 |
BF245A Features
This device is designed for VHF/UHF amplifiers
Sourced from process 50
High Input Impedance
Low Gate-Source Leakage Current
Low Noise
High Cutoff Frequency
Low Power Consumption
Thermally Stable
BF245A Applications
Low-Noise Amplifiers (LNA)
Signal Switching
Buffer Circuits
Radio Frequency (RF) Applications
Audio Signal Processing
Voltage-Controlled Oscillators (VCO)
Test and Measurement Equipment
Switching Power Supplies
BF245A Package
The BF245A is a Junction Field-Effect Transistor (JFET) in a TO-92 package, featuring three pins: Gate (G), Source (S), and Drain (D). It is widely used in signal amplification, switching, and analog signal processing applications, offering reliable performance in consumer electronics and RF circuits.
How to Use BF245A?
To use the BF245A transistor, first, connect the Source (S) pin to the ground or the negative side of your circuit. Then, apply a small positive voltage to the Gate (G) pin to control the flow of current between the Source and Drain (D) pins. The Drain is where the output current flows, so connect it to the load or circuit you want to control.
For basic switching, when you apply a voltage to the Gate, it allows current to flow from Source to Drain, turning the transistor on. If the Gate voltage is too low or zero, the transistor will remain off, and no current will flow. Keep in mind that BF245A is an N-channel JFET, meaning it typically requires a positive voltage to turn on and allow current to pass.
BF245A Alternatives
If you're looking for alternatives to the BF245A transistor, consider options like the BF245B, BF245C, 2N5457, , or BF256A. These are all N-channel JFETs with similar characteristics in terms of voltage ratings, current handling, and switching performance.
FAQs
What is the BF245A?
The BF245A is an N-channel Junction Field Effect Transisto, typically used for amplifying weak signals in high-frequency applications. It has low noise and high input impedance, making it suitable for RF amplifiers, audio applications, and signal processing.
How do I connect the BF245A to a circuit?
Source (S) goes to ground or the lower potential in the circuit.
Drain (D) is connected to the load or power supply.
Gate (G) is used for controlling the flow of current between the drain and source by applying a negative or positive voltage.
What are the common issues when using BF245A?
Thermal runaway: Ensure proper heat dissipation to avoid overheating.
Gate leakage: Excessive voltage on the gate may lead to leakage or damage, so always stay within the recommended limits.
