Need to design a Photodiode amplifier circuit

[Ejaz]

I need to build a circuit using Photodiode that will receive light from ultraviolet incandescent lamp (50/60 Hz line voltage), amplify and filter the signal and give dc output depending on the amplitude of the light. I'll be using an ultraviolet Photodiode for this purpose. Any help would be highly appreciated. Thanks in advance!

 

[Lewish]

Take a look at the application notes on the Linear Tech website>>

http://www.linear-tech.com/

Jim Williams did an app note on that very thing and the note gives some best choices for the opamp and circuit layout. I did one last year for a near IR, but don't recall offhand what opamp I used. Additional stages were added to give DC offset adjustment capability and more gain.

Really very easy to do if noise won't bother you and you aren't expecting a linear response.

Hope this helps.

Lewis

 

[tiki]

Hi Ejaz,
take a look also at the BurrBrown (now TI) application notes, they describe photodiode solutions very clear, also with respect to noise problems.
For TIAs with high gain look for OPA with very low bias current (significantly lower than dark current of the Photodiode) and gain unity. Some appnotes explain, how to work with non unity gain stable OPA, but my experiences...
For low speed applications the non biased diode solutions (diode directly connected between both +/- inputs of the OPA) seem to be advantageous: the diode provides no dark current.
I also used this solution sometimes for high sensivity amps:

http://www.ibtk.de/project/tsm/vsmsens1.jpg

http://www.ibtk.de/project/tsm/tc6_prin.pdf

tiki

 

[nbucska]

A cheap way to reduce the need for hi-performance amplifier
is to chop the light and use narrow band filter. <nbucska@pcperipherals.com>

 

[jbartos]

Suggestion: Visit

http://www.ioffe.rssi.ru/RT/IWRFRI2000/b2.html

http://www.controlvisioninc.com/hvoftech.html

Lewis, D.P., D. Butts, 1998. Ultraviolet Control for Zebra Mussels-The Evolution of Non-Chemical Alternative, Aquatic Sciences Inc.
etc. for more info

 

[xray]

Ejaz;
I have just completed a circuit that does this very thing only utilizing a 1N4148 diode to give DC output of visible light.I utilized an LM6482 by National a dual opamp chip. first opamp configured into a voltage follower to handle the DC offset into the second opamp. The second configuration was a non-inverting with the diode current running through a shunting resistor at the non-invert terminal. The diode current runs through the shunting resistor to convert to a voltage. The DC offset of the voltage follower replaces the ground connection of the resitance between the negative terminal and the ground in the non-inverting configuration. This allows one to utilize a potentiometer in the feedback to vary ones gain wihthout affecting the DC offset voltage. Well anyways if you would like a schematic and the equations governing the operation of the simple configuration email me. drollinger@montana.net

Cy Drollinger