BS 170 Amplifier with worst case inter electrode capacitances - with NPN Cascode transistor

205

02:18:52

Using the cascade configuration considerably improves the performance of the bs170 mosfet at least up to about 20-30 KHz.

Note that the capacitance values were taken from the Fairchild datasheet for the bs170.

published 6 years ago

hurz

6 years ago

Needs a lot of adjustment.

eekee

6 years ago

The circuit as a whole neither amplifies current nor voltage. It could amplify current, that 1MΩ resistor could be 10kΩ with only a 50% drop to output voltage. As it is, the circuit demonstrates no improvement over a single wire with no transistors. :)

gasboss775

6 years ago

The 910K resistor that was at the input was a mistake, however the point of the demonstration was in showing that the cascode configuration could improve the hf response of this sort of amplifier. Selecting a lower input resistor would be another way of circumventing the effect of drain gate capacitance.

hurz

6 years ago

In your first BS170 circuit you talked about “audio“ amp. Now its a HF amp? BS170 is.perfect for audio amps check your circuits with a better BS170 model and some corrections to your circuit http://everycircuit.com/circuit/5509143518773248

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