Basic Op-amps design problem

[clfalan]

Hi,
I just start learning op-amps and trying to build some basic circuits. Here is a circuit I am trying to build.

The left one is a transimpedance amplifier (0-2.5mA) and the right one is a bandpass filter from lm324 datasheet(center frequency is 50Hz, 10Hz bandwidth and 1 gain).
The maximum input current is 2.5mA and I want to convert it to 3.3V using lm324(this is the only op-amps I have) but no matter how I change the gain of the inverting amplifier(R8 and R11), the output voltage does not go over 2V and the graphic is not sine wave anymore.

I do not really know how to read the datasheet of lm324 so do not know what is the limitation of this op-amps.
Is there any way to make this circuit work? Could I add a DC offset to the output to shift the waveform up?

Thank you for your time in advance.

(Sorry for my bad English)

 

[crutschow]

The LM324 is single-supply but not a rail-rail type op amp so the maximum output voltage is only about 1.5V below the positive supply voltage (look at the output voltage limits in the data sheet relative to the supply voltage), thus it clips the output signal above that voltage.
So you either have to increase the op amp supply voltage or reduce the signal amplitude or go to a rail-rail op amp.

Adding an offset would not help.
The plus and minus output voltage you see is due to the output capacitive coupling.

 

[LvW]

What is the purpose of R4 (causing positive feedback)?

 

[Audioguru]

I agree that R4 should be removed.
The output shows severe clipping because the input signal is not biased at negative half the supply voltage then the transimpedance amplifier is not biased correctly.

 

[clfalan]

By adjust R15 and increase V+ to 10V, I got the graphic I want. I will put a diode at the output to cancel the negative voltage. Thank you for your help!

 

[clfalan]

I am not sure what the R4 does in the circuit neither. I just copied this circuit from the lm324 datasheet.

 

[LvW]

I am not sure what the R4 does in the circuit neither. I just copied this circuit from the lm324 datasheet.

OK - I see. The circuit is a bandpass with Q=25. This Q can be realized either internally (direct feedback around U1 opamp) or using the shown "overall feedback" (via R4).
Hence, for the given dimensioning R4 is necessary.

 

[Audioguru]

Is the input signal an AC current swinging positive and negative around 0V? Or is the input signal only sinking current to ground and letting the input of the transimpedance amplifier go positive by its input bias current when the input signal current is less?

I see your R4 in National Semi's datasheet that makes the Q very high at 25 and causes the output to severely clip.

 

[FvM]

I will put a diode at the output to cancel the negative voltage.

If you don't want a bipolar output voltage, why don't you omit the output capacitor? A diode would result in variable DC level.