This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

very small input voltage amplifier at 1Mhz

Part Number: LM7171

Hi

Ive decided to try for the lower noise ic(THS4031) of 1.6uV  as it has a much lower noise I/p as suggested by Sean, here is my circuit below.  To recap I`m trying to amplify 10uv signal but having problem with noise. Does this circuit look suitable, apart from layout and making on  a pcb and adding a ground plane is there anything else I should be doing.  thanks for any help in advance. 

  • Hi Paul,

    I think the circuit with the THS4031 looks suitable. For the layout recommendations, I would recommend reading through the layout guidelines mentioned in the THS4031 datasheet. You could also include a placeholder for parallel caps across Rf and Rg just in case if you run into instability issues but the amplifier circuit as such looks stable. In-order to reduce noise, you could try reducing the Rf values and subsequently the Rg value keeping the same gain as shown in the below simulation.

    Best Regards,

    Rohit

  • Thanks for your help Rohit, I will build the circuit and see how it well it performs. Much appreciated