BF245, a JFET transistor produced for many decades by several companies, has joined the list of discontinued components. However an equivalent replacement exists in an SMT package and its name is BF545.
BF245 in a TO-92 package has been one of the first transistors, which were mass-used. That’s why it’s no wonder, that the BF 245 is nowadays familiar to every experienced technician. As a transistor with a very high input resistance (tens of MOhm) and a relativlely low noise, it’s gained a global popularity and served to many beginning technicians at an assembly of their first radio-receivers. There are many other FET transistors on the market nowadays, thus the usage of BF245 is substantially smaller. Moreover, a majority of electronics is produced with SMT components, what probably was one of more reasons why all main producers have discontinued the BF245.
However, BF245 is still an interesting transistor, that’s why it will be henceforward available in a SOT23 SMT package as the BF545. It is available in 3 groups A, B, C – sorted according to IDSS at VGS=0. Directly from our stock are available BF545A, BF545B and BF545C from company NXP (originally Philips). Detailed information can be found in the BF545 datasheet, as well as in the RF Manual document.
BF245 – the legend is leaving, the successor comes - [Link]
All out of TO-220′s? Thinking maybe you can eke enough performance out of a smaller transistor?
Want to squeeze a bit more current through those inexpensive TO-92 package transistors? Then add a small metal heatsink. I made this for a PWM DC motor driver, as some 2N2222 bi-polar transistors were handy. Of course, we should only operate components within their factory spec, but it’s good to know this type of desperation has been previously explored – just in case. [via]
DIY TO-92 heatsink - [Link]