TO-92 vs sot-23 transistors for power

There's little reason to drive a 50 ohm resistor with double the output voltage to get a 50 ohm source. I did a design with limited Vdd and used positive feedback to make a 12.1 ohm resistor look like a 50 ohm output impedance. I was able to get an 8 volt swing into 50 ohms from an LM8272 op amp on a unipolar 12 volt supply.

The LM8272 is a well-controlled op-amp, doing that with a RF power amplifier with margin phase characteristics is a risky proposition.

An extra second per part, bending the leads so they'll fit?! You must be crazy! I hope you never wrote a book or anything! ;-)

(I never had a need for it, but occasionally you'll see one with the middle lead kicked up like one of the Rockettes, and board routed out around it. There's a couple of these inside my monitor, for driving a pulsed 1.5kV focus electrode or something. No better way to get the creepage needed; only downside is, most TO-220's aren't grooved between the leads, so you're very quickly package limited on that.)

I also like the TO-92s with 0.1" pitch. (But if I accidentally buy the unformed lead variety, that's *two seconds* wasted!)

Tim

One purpose: standing parts will not be prone to being bent over, and eventually suffer a fatigue failure. Not all parts are vulnerable, but parts around the edges are; this rule always applied solves the problem. And as you say, it's only an extra second.

It also sometimes helps with routing, etc.

in my experience stagger pins just means that if they get bent over it will be where the pins the package and break the pins, instead of being some where along the pins where it isn't so critical

-Lasse

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More than a second, but I've bent leads like that. (low volume.) Also with the to-220 on the top side of the pcb, with a 1/4" brass standoff through a hole to the heat sink below. (less heat)

George H.