atferrari
Full Member level 4
- Joined
- Jun 29, 2004
- Messages
- 237
- Helped
- 7
- Reputation
- 14
- Reaction score
- 3
- Trophy points
- 1,298
- Location
- Buenos Aires - Argentina
- Activity points
- 1,996
I am in the middle of an impasse in my way to a design with my newborn knowledge on CANbus and decided trying to complete the design of a VCA for a function generator, pending for more than 6 months.
Accepting that I will reinvent the wheel, my questions:
a) From this two transistors, which should be the best for using, previously matched?
2N3904 NPN low signal hFE 40 to 300
BC337 NPN audio hFE 100 to 360
Both are really cheap so cost is not a point here.
b) Given stable / same conditions for the testing of the transistors, should I look for just same Vbe or should I look for same hFE? Measuring Vbe is much easier and faster in a breadboard. Did some practice today.
I've read a lot in the Web but found too much blah blah on the subject.
Comments on the whole subject, welcome.
OTA's are not an option, at least for the moment.
Accepting that I will reinvent the wheel, my questions:
a) From this two transistors, which should be the best for using, previously matched?
2N3904 NPN low signal hFE 40 to 300
BC337 NPN audio hFE 100 to 360
Both are really cheap so cost is not a point here.
b) Given stable / same conditions for the testing of the transistors, should I look for just same Vbe or should I look for same hFE? Measuring Vbe is much easier and faster in a breadboard. Did some practice today.
I've read a lot in the Web but found too much blah blah on the subject.
Comments on the whole subject, welcome.
OTA's are not an option, at least for the moment.