I'm in the process of designing a Transimpedance amplifier for an analytical instrument. The sample waveform (hand-drawn) is attached in the attachments. The requirement is to amplify a pulse kind of signal whose maximum amplitude is around 700 nA and the width of the pulse is around 1 ns. So, I need a high-speed transimpedance amplifier. My question is what are the opamp parameters that decide the speed of the amplifier. I need a concrete relationship between slew rate, settling time, rise time, bandwidth/gain-bandwidth. And particular to the signal which parameter is most important so that I can choose the right opamp for the design. Regards M Arivalagan enter image description here

  • 2
    \$\begingroup\$ Good luck. If you google for one, please note the price. You are probably looking for an opamp with bandwidth in excess of 5 GHz. \$\endgroup\$
    – Andy aka
    Aug 24, 2019 at 12:09
  • 1
    \$\begingroup\$ You forgot to give what gain on the output you want, this will determine the slew rate and Gain Bandwidth Produce scaling lets say you have 100MHz GBP, and a gain of 100, well then you have a Bandwidth of 1MHz, as I am assuming you would like a rather large gain you may have to approach it with a cascaded amplifier to keep the bandwidth high enough at the cost of some added noise. \$\endgroup\$
    – Reroute
    Aug 24, 2019 at 12:21
  • \$\begingroup\$ You may find this enlightening: electronicdesign.com/analog/… \$\endgroup\$ Aug 24, 2019 at 13:11
  • 1
    \$\begingroup\$ It is important to know the source impedance ( usually, the source capacitance) to design a trans impedance amplifier. More information is needed. \$\endgroup\$
    – user69795
    Jul 8, 2021 at 22:08

1 Answer 1


Consider this: a common-base amplifier


simulate this circuit – Schematic created using CircuitLab

For more bandwidth, increase the Vce to reduce Cob; thus take +5v to +10v.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.