[volt-nuts] How to measure micro-amp currents and have low impedance?

[Bruce Griffiths]

Bob Paddock wrote:
>>> I'm not familiar with Patterson's work, and Google was not much help.
>>>
>>> Will you point me to a specific paper or schematic please?
>>>
>>>       
>> Its not particularly new, you have probably seen the circuit many times
>> (the name has been around for at least 50 years or so) see:
>>     
>
> You're right, I've seen lots of those circuits, just never recall the
> name Patterson
> being mentioned related to them.
>
> Thank you for the link.
>
>   
>> http://www.electronics.dit.ie/staff/ypanarin/Lecture%20Notes/DT021-4/6LogAntiLogAmplifiers.pdf
>>     
>
>   
Probably because it is sometimes misspelled as Paterson  its mentioned in:
US Patent 7395308,
http://www.ee.bgu.ac.il/~pel/pdf-files/jour37.pdf
<http://www.ee.bgu.ac.il/%7Epel/pdf-files/jour37.pdf>
http://www.biochemj.org/bj/154/0277/1540277.pdf

I first came across it in a Phibrick application note.
Patterson's original paper appears in:
Review of scientific Instruments (1963) 34, 1311-1316.

Bruce