bigger die = less ΔT = less variation between umbrella's handle (base) and umbrella's shield (emiter)
that , besides lesser possibility of getting magic smoke out of wimpy T092
that , besides lesser possibility of getting magic smoke out of wimpy T092
TO-126 is an intermediate step between TO-92 and TO-220 - can get smaller die, lower Cob,e parts
smt SOT_223 is another - in fact it could be soldered "thru hole" if you straighten the j leads with pliers
but easy to hand solder too even on the standard smt footprint
smt SOT_223 is another - in fact it could be soldered "thru hole" if you straighten the j leads with pliers
but easy to hand solder too even on the standard smt footprint
Nelson said that mosfets as cascode are more prone to oscillate. Only a couple of days ago I made a cascode of a 2SA1011 - that one oscillated indeed.
But I had no base resistor and a capacitor from base to GND. The whole thing worked OK after I put a 18 ohm resistor in series with the base.
One more thing. Simulations indicate that the gm of the cascoded VAS will be slightly higher when using a bipolar as cascode ( if the VAS is a mosfet that is).
This is probably due to the higher gm of a bipolar - the current variations are less present on the drain and a mosfet VAS run with low voltage may actually both distort more and have a lesser gm.
But I had no base resistor and a capacitor from base to GND. The whole thing worked OK after I put a 18 ohm resistor in series with the base.
One more thing. Simulations indicate that the gm of the cascoded VAS will be slightly higher when using a bipolar as cascode ( if the VAS is a mosfet that is).
This is probably due to the higher gm of a bipolar - the current variations are less present on the drain and a mosfet VAS run with low voltage may actually both distort more and have a lesser gm.
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