I’ve been looking at the theoretical principles that govern the voltage-controlled amplifier (VCA) recently and came across some simple VCA designs that caught my attention. A common technique involves a JFET and an opamp to achieve VCA type operation by using the JFET as a voltage-controlled resistor somewhere in the input path. I’ve seen a…
Tag: jfet
MOSFET vs. BJT
a good rule of thumb pulled from this forum thread (http://www.electro-tech-online.com/general-electronics-chat/39339-mosfet-vs-bjt.html): Need a switch to be fully-on fully-off and carry lots of current -MOSFET Need a switch that needs to have lowish capacitance – BIPOLAR Need a cheap, dirty 2 or 3 component current source – BIPOLAR Need a low voltage/noise amplifier – BIPOLAR Need…