I am designing a transimpedance amplifier to amplify the current coming from a photodiode.
With an input frequency of 1MHz and aiming to optimize the noise in the circuit, what is the recommended approach that should be followed?
I am designing a transimpedance amplifier to amplify the current coming from a photodiode.
With an input frequency of 1MHz and aiming to optimize the noise in the circuit, what is the recommended approach that should be followed?
Please check out www.analog.com/photodiode. It has a couple of noise screens you can look at and play around with options
General tips:
- Get your photodiode capacitance as low as you can (reverse biasing it with a voltage great way to do this)
- Make the circuit response as slow as you can stand while still getting the speed you need. You can do this by any of the following A) filter after the TIA stage B) choosing a slower op amp C) Larger feedback cap
Excellent point thanks Matt.
Another resource that will help is this KWIK FAQ (1MHz, Single Supply, Photodiode Transimpedance Amplifier (TIA) Design) will help you.
This document is a step-by-step design example that will take you through the design of a TIA for the measurement of uric acid concentration samples.
It may not be the exact application that you have but the techniques used should certainly resonate. The KWIK FAQ covers the design specifications, design considerations, as well as worked examples for each step of the design. It also goes through in detail the noise analysis for the circuit design as well as how to tune and further optimize and uses LTspice to show the results through simulation.
Between the Photodiode online tool (https://www.analog.com/photodiode) and the KWIK FAQ https://ez.analog.com/precision-technology-signal-chains/precision-wide-bandwidth-signal-chains/w/documents/16183/1mhz-single-supply-photodiode-transimpedance-amplifier-tia-design you should have everything you need!