[sdiy] help interpreting diagrams with Mosfets

[lanterma at ece.gatech.edu]

On May 25, 2011, at 11:16 PM, dan snazelle wrote:

> http://www.scholarpedia.org/article/Silicon_neurons

...

> 1. can these Mosfets (?) be replaced with CMOS inverters or simply JFETS ?

In general, no... of course if you see a couple of MOSFETS configured as an inverter you can use an inverter, but in general, no.

All CMOS indicates is a MOSFET process that has both nFETs and pFETs. 

They have many similarities to JFETs but you generally can't do a 1-for-1 replacement.

> 2. are they just symbols for amplifiers?

No, no... MOSFETs are their own thing.

ONe word of caution is that the "op amp symbols" here are mostly OTAs. But circuits people often write OTAs using a voltage bias input instead of a current input; there's usually an implicit nFET or something inside there doing a voltage-to-current kind of conversion.

If you want to putter around with MOSFETs a 4007 isn't a bad chip to start with.

- Aaron