• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 50 subscribers
  • Views 625 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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 low transimpedance gains with OPA847

Rebecca Gabzdyl
Prodigy 10 points

I plan to use a photo diode (C diode = 6pF) together with a wideband transimpedance amplifier as shown Figure 1 of SBOA122 - Transimpedance Considerations for high speed amplifiers.

I have a peak diode current of ~25mA (very high compared to other applications I have found) and want an output voltage swing of 1V peak to peak and 3dB BW ideally >= ~250MHz.

This would give an Rf = 40 ohm. Would this circuit be OK with such a low feedback resistor as in SBOA122 data is only given for Rf > 1 kohm?

 

  • 0
    Intellectual 580 points
    Hi Rebecca,

    I'm facing a similar task: I_in=~4mA, F_in=~40MHz, thus the required gain is very low.
    So the frequently suggested high gain trans-impedance circuits seems not suitable.
    Did you come up with some solution to this task?
    Would you mind to share the general principle?

    Thanks,
    David.