The FZT653 in SOT223 package has 3 normal terminals at the bottom, collector, emitter, base. However, it also has a collector on the top. Why is this so? Which is the real collector.
\$\begingroup\$
\$\endgroup\$
6
asked Jan 14, 2016 at 11:07
-
\$\begingroup\$ What do you mean with "real"? They are both the collector, use whichever you want \$\endgroup\$– PlasmaHHCommented Jan 14, 2016 at 11:12
-
\$\begingroup\$ So either could be used but not both. Why does mankind need a bjt package that had two possible collectors, one bigger than the other and both pointing in opposite directions? \$\endgroup\$– quantum231Commented Jan 14, 2016 at 11:19
-
\$\begingroup\$ What defines a "normal" connection? \$\endgroup\$– Andy akaCommented Jan 14, 2016 at 11:22
-
\$\begingroup\$ Were these questions answered to your satisfaction: electronics.stackexchange.com/questions/100141/…? What about this one: electronics.stackexchange.com/questions/108214/…? It's a small price to pay for good advice and you have plenty of questions raised that you haven't "accepted". There were just two that I remember. \$\endgroup\$– Andy akaCommented Jan 14, 2016 at 11:28
-
\$\begingroup\$ Dear Andy, all of my questions are answered to satisfaction on this forum. Particularly the answers given by you, sephro, olin and martin are the best. I will be careful that I always accept an answer by clicking on the tick from here on. \$\endgroup\$– quantum231Commented Jan 14, 2016 at 11:50
|
Show 1 more comment
2 Answers
\$\begingroup\$
\$\endgroup\$
Both collectors are connected together inside the package. The one on the "top" (or tab) is normally soldered down to a an area of copper on the PCB to act as a heat sink. To achieve the maximum rating for this transistor (3W power dissipation) this copper pad needs to be about 50mm x 50mm (see the datasheet).
In practice you should connect both collectors together in your circuit.
\$\begingroup\$
\$\endgroup\$
The above can only realistically mean that C=C i.e. two connections to the same place.
answered Jan 14, 2016 at 11:56