Hi all
I'm now designing a class AB mosfet amplifier with IRF240 and IRFP9240.
Since now I have not designed any mosfet amplifier and any amplifier with high voltage supply.
The supply voltage are probably +-45/50V
I'm thinking to use mmbt5401/mmbt5551 (th: 2n5401/2n5501) or fjv992/fjv1845 (th: ksa992, ksc1845) for the current mirror input stage if I'll wish more hfe.
For the VAS i'm thinking to use ksa1201/ksc2881.
What do you think about those transistors? I haven't seen those in many design.
Are a good choice?
Any other idea regarding SMD transistor for driving a 100V mosfet design?
PS: sorry for my bad english.
I'm now designing a class AB mosfet amplifier with IRF240 and IRFP9240.
Since now I have not designed any mosfet amplifier and any amplifier with high voltage supply.
The supply voltage are probably +-45/50V
I'm thinking to use mmbt5401/mmbt5551 (th: 2n5401/2n5501) or fjv992/fjv1845 (th: ksa992, ksc1845) for the current mirror input stage if I'll wish more hfe.
For the VAS i'm thinking to use ksa1201/ksc2881.
What do you think about those transistors? I haven't seen those in many design.
Are a good choice?
Any other idea regarding SMD transistor for driving a 100V mosfet design?
PS: sorry for my bad english.
I use MPSA42 for LTP and its constant current source.
For the VAS and its current source I use MJE340 and MJE350.
For the VAS and its current source I use MJE340 and MJE350.
I don't know what voltages the smd types are available in, but for a +-50Vdc amp you may have to consider cascoding to get these tiny devices within their thermal and voltage limits.
For both LTP and VAS you need good hFE over the range of working currents, low Cob at 5V and 10Vce, medium to high fT at your working currents.
For both LTP and VAS you need good hFE over the range of working currents, low Cob at 5V and 10Vce, medium to high fT at your working currents.
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thanks for answares.
Both couple mpsa42/92 and mje340/350 have smd brothers.
I prefer avodi cascode input stage for many reason, the first is that increase complexity without a sound improvement.
SMD transistors placed correctly offer a better termal uniformity and less noise than a trough hole solution.
I will calculate the heating of all transistor during the components choice.
Both couple mpsa42/92 and mje340/350 have smd brothers.
I prefer avodi cascode input stage for many reason, the first is that increase complexity without a sound improvement.
SMD transistors placed correctly offer a better termal uniformity and less noise than a trough hole solution.
I will calculate the heating of all transistor during the components choice.
hi pdp11,
my english is also bad, so I hope we can communicate 😀
Do you know == Diodes, Inc. == ? Since there are a lot of interesting transistor.
my english is also bad, so I hope we can communicate 😀
Do you know == Diodes, Inc. == ? Since there are a lot of interesting transistor.
I like SMDs, but I don't like to work with it. So I build my amps with big devices. In one of my next projects I will evaluate an amp with SMDs.
MMDT5401 and MMDT5551 are very interesting, because there are two transistors in one case. Important for mirrors and diffamps. I have very good experience with 2N5551/5401, so I give them a try.
MMDT5401 and MMDT5551 are very interesting, because there are two transistors in one case. Important for mirrors and diffamps. I have very good experience with 2N5551/5401, so I give them a try.
Most of those SMDs come in duel or quad packages which makes for many less 'components' to solder.
i think sanyo 2sa106/2sc2362 is obsolute now . unable to find
i would like to know that 2sa1207/2sc2909 can be used for ltp .
data sheet here http://www.audiolabga.com/pdf/2SA1207.pdf
i would like to know that 2sa1207/2sc2909 can be used for ltp .
data sheet here http://www.audiolabga.com/pdf/2SA1207.pdf
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