Transistor BF257 NPN, 160V TO-39

Transistor BF257 NPN, 160V TO-39

Transistors

Reference: TRBF257

Part.No: BF257

€1.20

In Stock

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The BF257 is a high-voltage NPN Bipolar Junction Transistor (BJT) in a TO-39 metal can package. Designed for CRT display driver circuits and other high-voltage switching applications requiring robust thermal management.

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Description
Product Details

BF257 High-Voltage NPN Transistor – CRT Display Driver & Switching

The BF257 is a rugged NPN transistor purpose-built for high-voltage applications, particularly CRT display driver circuits. Its TO-39 metal can package provides superior heat dissipation, making it ideal for demanding switching roles where thermal stability and voltage headroom are critical.

Functions & Applications

High Collector-Emitter Voltage (160V): Handles demanding CRT driver circuits and industrial switching without voltage stress.
TO-39 Metal Can Package: Excellent thermal conductivity for superior heat dissipation; compatible with standard star-shaped heatsinks.
Robust Design: Built to withstand the rigorous operating conditions of legacy video equipment and high-voltage switching circuits.
Reliable Performance: Time-proven reliability in vintage and industrial electronics requiring sustained high-voltage operation.

Technical Specifications

Parameter	Value / Specification
Transistor Type	BJT (Bipolar Junction Transistor)
Polarity / Channel	NPN
Package / Case	TO-39
Collector-Emitter Voltage (Vceo)	160V
Mounting Type	Through-Hole (THT)

Frequently Asked Questions

Q: Do I need a heatsink for the BF257?
A: Yes, in CRT driver circuits, a small star-shaped aluminum heatsink is typically mounted directly onto the TO-39 metal case to manage the heat generated during sustained high-voltage switching.

Q: What is the complementary PNP part for BF257?
A: The complementary PNP transistor is the BF258, which shares the same high-voltage rating and TO-39 package.

Notes

Legacy/vintage part commonly found in CRT display equipment. High-voltage application; always verify circuit design and ensure proper heatsinking to prevent thermal runaway.

Note: Price refers to one (1) piece. The component is shipped in bulk without individual packaging.

Transistor Type: BJT (Bipolar Junction Transistor)
Transistor Polarity / Channel: NPN
Transistor Case Style: TO-39

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