[Amps] a 'circuits' question

[Steve Thompson]

On Thursday 09 September 2004 03:21, Dan Sawyer wrote:
> Steve,
>
> Thank you. I was trying to drive the MOSFET in the linear region. I
> figured gm would be accurate for the linear region and that bias
> adjustment would be accurate for a particular initial condition. I was
> speculating that even given those two points the shape of the drive
> curve might not be identical. Is this true??

It could be true although, in my experience, mismatch has to be very 
significant before there's any appreciable effect on overall performance 
(assuming matching for bias voltage, or separate bias controls). If you do 
the threshold and gm tests, then any pair with gm within 10% from the same 
batch code is likely to be fine. For dynamic matching, a gain selection at 
the intended operating power is probably all you need.

Steve