how to design a photodiode preamp with 2Mohm transimpedance

photodiode preamplifier

supply:+15/-15;
gain:2.0M ohm transimpedance;
-3dB bandwidth:>=2M
power:<=300mW;
voltage drifft :<=10mV(full temperature);
input signal:0.5~4uA sinwave;

photodiode preamp

output voltage:>=1Vp-p

photodiode preamp considerations

The possible solution is the operational amplifier with the resistor R=2Mohm in feedback circuit.

photodiode preamplifier circuit

if do so,which type of opamp should be used? i can found anyone to justfy that demand? Colud theose resistor and opamp be integrated in one monothetic chip?

photo diode preamp

Or do there have any state-of-art circuit technique that could perform this function?

design of photodiode

ana*log device,
ad549K electrometer
Regards.

photodiode preamp schematic

ad549 can obtain hign transimpetance,but its bandwidth is so narrow when used as photodiode pre-amplifier,and more,where to find model(.mod or .lib)of this circuit?thanks.

apd preamplifier op amp

If the supply range 2.7 to 5.5V is not a problem, then use TI OPA380. On the product page you will also find link for the model

maranaza

avalanche photodiode preamplifier circuit

See link

http://www.ecircuitcenter.com/Circuits/opitov/opitov.htm

photodiode circuit opa380

the main problem is:gain>=120dBohm, and -3dB bandwidth>=2MHz,the above url can not achieve such target.

preamplifier photodiod

PONDERBOY,

You can make two-stage preamp. Read the BB Application Buletin "AB-075.pdf".

maranaza

photo diode preamplifier circuit

No one of "standard" OA not applicable for your design
you never get 2 M band with 2 Meg resistor (your parasitic capacitance
must be not more then 3*10^ -14 = 30 femtofarade !!!)

The only solution is - to use "RF" OA with very high bandwidth product, like

https://focus.ti.com/lit/ds/symlink/opa657.pdf

there is only a few such OA on the market and them
expensive enough but this is the only solution for you

photodiode preamplifier

BTW
A short calculation (see page 11 of datasheet) show,
that your design target not achievable even with this OA
Maximum 0.75 Mohm for 2MHz band
And most critical parameter will be photodiode capacitance
and layout parasitic of course ....
So try to think about avalanche photodiode to decrease transimpedance gain
needed or use logarithmic amplifier if you need only light signal level
measurement and not need exact waveform tracking

(see AD8304 or any other suitable from Analog Devices )

ab-075.pdf

Don't forget calculate noise level and compare to you usable
signal level and needed signal to noise for proper working.

big part of early post app-notes describe this problem

And dont't use DC-level as information
if application not need this - or transform this to
better format ie FM-modulation, pulse or A/D and datalink etc.

DC-coupled circurit whole way is very hard
to hold stable over time and temperature,
especially if arised DC-level error gained
at 120 dB DC-coupled amplified-chain...

Use AC-coupled solution if possible!

photodiode log amp

PONDERBOY said:

Or do there have any state-of-art circuit technique that could perform this function?

Click to expand...

Actually everything in electronics is state-of-art. Where this photodiode is applied, what is its application?

You will eventually force to do feedback with opamp and feedback is primary method for in-stability. In high frequency, the oscillators are made (one of the methods) by feedbacking (introducing in-stability) for a current amplifier which will cause the circuit to behave like an oscillator.

I am asking this question, because if you are saying bandwidth is 2MHz and not putting the upper limit. Opamp solution is ok for some cases or maybe not at all for 2MHz depending on application. You can do transimpedance using transistors.

120db transimpedance

0=<-3dB bandwidth<=2MHz,thx.

preamp photodiode

Could this problem be settled? or it can not find a way to settle this problem? Is it impossible?

op amp preamp circuit for avalanche photodiode

Here is my proposal:

Make multistage:

Stage 1 is current to voltage (transimpedance), using feedback amplifier and small feedback resistor (5kohm?) to give good bandwidth, even with parasitic capacitance (10pf would give 3MHz).

Stage 2 is voltage to voltage amplifier. Use gain = 400 to acheive 2Megohms in combination with 5kohm in 1st stage. For gain of 400, bandwidth of 2MHz, you would need greater than 800MHz GBW in amp. If needed, this can be 2 gain stages, each of gain 20x, each with GBW greater than 40MHz.

Overall result should provide 2MegOhm transimpedance, >2MHz BW.

To obtain high frequency, it is likely that you would need op-amps with external compensation, or compensated for minimum gain greater than unity. This widebands the amplifier at a cost of unity gain stability, but, since you are not using unity gain configuration, your circuit does not need to be unity gain stable! If you use external compensation, you should be able to tailor your bandwidth for your necessary gain.

You will need to evaluate noise and drift performance, as the output of the 1st stage will be amplified by 400x. I am not sure if this approach will meet all your requirements, but it should be able to obtain your bandwidth.

photodiode preamp bestellen

hoe to evaluate noise of photodiode preamplifier?the drifft is also very large which about 1mv per tem degree.