Edit History

Lab Journal

Version 2 (Andrew Starr, 10/19/2012 05:06 pm)

1 1 Andrew Starr 
h1. Lab Journal
2 2 Andrew Starr 






    3
    2
    Andrew Starr
    
h2. 20 Oct, 2012 - Tunnelling Current Amplifier simulation






    4
    2
    Andrew Starr
    






    5
    2
    Andrew Starr
    
The tunnelling current amplifier is an example of a _transimpedance_ amplifier: it converts a current input into a voltage output. This amplifier is a critical circuit in the microscope, so I have taken advantage of available electronic simulation software to test and tune the design before committing to a PCB.






    6
    2
    Andrew Starr
    






    7
    2
    Andrew Starr
    
h3. Bandwidth vs noise






    8
    2
    Andrew Starr
    






    9
    2
    Andrew Starr
    
In a transimpedance amplifier there is an unavoidable tradeoff between the bandwidth of the amplifier response and its output noise.