Hi good mornig,
As always when I write in English, sorry for my English.
We are trying to design a stage amplifier (front-end) to read the signal received from a SiPM.
I will said you, all we have learned and this post is for you to said TIPS or advices that can help us, because we are so noob.
The pulse from the SiPM is around 2mv Vpp and around 400ns width.
We have read that a efficient form is a preamplifier (Transinpedance, Fully diferential or non-inverting amplifier) and a second stage with a normal inverting amplification.

The normal schema we simulate is something like this:


We are amplifing the simulated white noise too and in our first stage we get some oscilation form the pulse. When we read some scheme, We can understand some capacitors and some resistances but many others we do not know why they put them in that place that are usually the same.

We are going to buy a few models (Opamps):

LMH6624
OPA1611
OPA847
OPA862
OPA380

Some advice like:
-Dont put so much noise in your simulation
-Dont buy OPA380 for that because it have a lot noise
or
-Put a capacitor in that place to reduce noise or oscilation

I dont know..., Im not electrical engienering, Im technician and Im trying my best.

 

Oscilant output at stage 1.

 

hi Sourc3,
This is my build of your circuit.
Is it the oscillation on the trailing edge of the pulse [ ringing] that you need to cancel out.??

E

 

hi Sourc,
This is a plot of the amplifier Frequency/Gain, signs of instability around 1MHz

E

 

@

hi Sourc,
This is a plot of the amplifier Frequency/Gain, signs of instability around 1MHz

E
View attachment 267584

Hi Ericgibbs! Thanks a lot again, You have helped me other time .

Yeah I want to reduce that oscillations, I only need to amplified the pulse. And other things is that noise/pedestal is amplified too and I don't want that.

Conserning the gain/amplification, that bandwidch is related to the pulse width no?

 

hi Sorc,
Check this option.
+/-5V with different OPA and component changes.
E

 

Thats perfect Eric, maybe we need lower amplification because the sensor can send tha same pulse multiplicated for 8, 9 or 10.
And for finish, can u explain me a bit your modifications and my erros?
Best regards!

 

Your errors:
1) The parts on your schematic are too far apart making them look very tiny.
I cropped them together and made the schematic larger.
2) Your needed gain is so low that a single opamp can easily do it.
3) Your 1st opamp needs to has a resistor to ground on its + input for a reference bias of 0VDC.
4) The input resistor value on your 2nd opamp is too low for most opamps to drive.
5) The output load resistor value is also too low for most opamps to drive.

 

Sourc - I am curious what SiPM you are going to use or are using in your simulation? I have questions about how effective these devices will be at low pulse widths due to the spec sheet item called "recharge time". For some Onsemi devices this is around 62 ns.

 

Your errors:
1) The parts on your schematic are too far apart making them look very tiny.
I cropped them together and made the schematic larger.
2) Your needed gain is so low that a single opamp can easily do it.
3) Your 1st opamp needs to has a resistor to ground on its + input for a reference bias of 0VDC.
4) The input resistor value on your 2nd opamp is too low for most opamps to drive.
5) The output load resistor value is also too low for most opamps to drive.

Hi Audioguru again!

Thanks a lot for you explication, it what I need for learnt, I will recorded that tips about resistances and the second stage amplifier isused for all the front-end devices I saw, looks like the need a preamplier stage on nitrogen normally and a second stage with normal amplifier.

 

Sourc - I am curious what SiPM you are going to use or are using in your simulation? I have questions about how effective these devices will be at low pulse widths due to the spec sheet item called "recharge time". For some Onsemi devices this is around 62 ns.

Im using Hamamatsu and FBK (Fundacione Bruno Kesner), they have 400ns and 4us repectively. But I dont know how to simulate it, I use a pulse, the final test will be with real SiPMs.