BF245B,112

Overview

The BF245B is an N-channel silicon field-effect transistor from the BF245 series, housed in a plastic TO-92 variant (SOT54) package. It features interchangeable drain and source connections and supports frequencies up to 700 MHz. Key electrical parameters include a drain-source voltage of ±30 V, a gate-source cut-off voltage range of -0.25 V to -8 V, and a typical forward transfer admittance of 6.5 mS at 1 kHz. The device operates with a total power dissipation of 300 mW and exhibits a noise figure of 1.5 dB at 100 MHz.

Feature Summary

• Symmetrical junction field-effect design allowing interchangeable drain and source connections
• Capable of operation at radio frequencies up to 700 MHz
• Low noise figure suitable for sensitive signal amplification
• General-purpose construction in a standard through-hole plastic package

Applications

• LF amplifier circuits
• HF amplifier circuits
• DC amplifier circuits

Procurement Notes

Verify the specific ordering code matches the required performance bin, as the BF245 series includes variants with different current ranges. Confirm the package type corresponds to the SOT54 outline provided in the datasheet. Ensure static discharge precautions are observed during handling due to the sensitivity of the gate-source input. Check the most recent product status on the manufacturer website before finalizing procurement.

Selection Notes

Select this component when designing general-purpose amplifiers requiring symmetrical terminal functionality. The BF245B offers a mid-range drain current specification compared to other series members. Consider the thermal resistance characteristics for heat dissipation requirements. Verify that the operating frequency and noise figure meet the specific application needs.

Part Context

This part belongs to the BF245 family of N-channel silicon JFETs manufactured by NXP Semiconductors. The series includes BF245A, BF245B, and BF245C variants, differentiated primarily by their zero-gate-voltage drain current ranges. These transistors are designed for general-purpose applications where low noise and high-frequency response are beneficial.

Replacement Considerations

Direct replacements within the same family include the BF245A and BF245C, though they possess different drain current specifications. Cross-manufacturer equivalents may exist but require verification of pinout compatibility and electrical parameter alignment against the original datasheet limits.

FAQ

Can the drain and source terminals be swapped?

Yes, the BF245B features a symmetrical junction design that allows for the interchangeability of drain and source connections.

What is the maximum operating frequency?

The device supports frequencies up to 700 MHz, making it suitable for HF applications.

How is the gate protected during handling?

The device is supplied in an antistatic package, and the gate-source input must be protected against static discharge during transport or handling.