BF245B_D74Z

Overview

The BF245B_D74Z is an N-channel depletion-mode Junction Field-Effect Transistor (JFET) manufactured by onsemi. Designed for VHF and UHF applications, it operates within a drain-source voltage range of ±30 V and supports a maximum continuous drain current of 100 mA. The device features a TO-92 package (Case 29-11/TO-226AA) with three pins. It exhibits a total device dissipation of 350 mW at 25°C ambient temperature, derating by 2.8 mW/°C above this threshold. The component is suitable for low-noise amplification in ultra-high frequency bands.

Feature Summary

• N-channel silicon construction optimized for VHF/UHF signal processing
• Depletion-mode operation providing inherent conductivity without gate bias
• High noise figure characteristics suitable for sensitive RF front-end stages

Applications

• VHF/UHF low-noise amplifier circuits
• RF mixer stages in communication receivers
• Impedance matching networks in antenna systems

Procurement Notes

Verify the specific suffix _D74Z against official onsemi documentation to confirm tape-and-reel packaging specifications. Ensure compliance with RoHS directives if required by the target application. Cross-reference the part number with the manufacturer's current database to account for any nomenclature changes resulting from corporate integrations or legacy product updates.

Selection Notes

Select this component when designing circuits requiring an N-channel depletion JFET for VHF/UHF frequencies. Consider the TO-92 package constraints for thermal management, as power dissipation decreases significantly above 25°C. Evaluate the 30 V breakdown voltage against peak RF swing requirements to prevent device failure during high-signal conditions.

Part Context

The BF245B series belongs to onsemi's portfolio of discrete JFETs intended for radio frequency applications. These devices are commonly used in broadcast and communication equipment where low noise and stable gain at high frequencies are critical. The BF245B variant specifically denotes the N-channel depletion mode configuration within this family.

Replacement Considerations

Publicly documented substitutes include the BF245A and BF245B variants from onsemi, which share similar electrical characteristics but may differ in noise parameters. Other manufacturers produce equivalent parts such as the 2N5484 or J308, though pinout and exact RF performance metrics should be verified before substitution.