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HI, I don't know much about electrical circuits(student), I found this schematic (below attached picture) on the web. It receives a negative pulse from a photomultiplier and amplifies it to an acceptable range for PC microphone input for spectroscopy. But I want to connect it to the esp32 ADC instead. But it works at 5 volts and I need the voltage not to go higher than 3.3 volts for esp32 input. I tried chat-gpt and other AI apps, but they gave me different values every time. (Photomultiplier makes current pulses in a few nanoseconds range). Can someone figure out the values of all components for 3.3 volts supply and maximum 3.3 volts output?
(I attached datasheet with full information of it.)
information provided by datasheet: The signal conditioning circuit, composed of R8/C9, R9/C10 and R10/C11, is followed by an amplifier. Finally, the signal is lowered impedance to limit the noise on the cable. The transistor T3 amplifies the signal attenuated a lot in the filter. The transistor T4 and the capacitor 330nF lower the output impedance, minimizing the noise that the signal wire can collect for coupling with the power supply wire and with external disturbances. C12 and R13 are also a third low pass cell that enlarges the pulse and paves its tip. The pulse of this output (DC coupled and without undershoot) is also perfect for the costly MCA hardware equipment, of ancient design. R9, R10, C10 and C11 form the "Pulse shaper" that broadens the pulse to over 100 uS to increase the resolution of rows and slows its rising edge to minimize noise due to the "ringing" R8 and C9 form the "Pole-Zero Cancellation", well described in the literature, which eliminates the "Undershoot" and produces a pulse that goes to zero in the shortest possible time. The diode D6 prevents that the voltage goes negative and protects the base of the transistor. To positive voltage limit is accomplished by the transistor base emitter junction. In addition the resistors R8, R9 and R10 limit the current to levels absolutely safe, even if C8 go shorted by sending all the high voltage to the transistor, this would not break anyway.
(I attached datasheet with full information of it.)
information provided by datasheet: The signal conditioning circuit, composed of R8/C9, R9/C10 and R10/C11, is followed by an amplifier. Finally, the signal is lowered impedance to limit the noise on the cable. The transistor T3 amplifies the signal attenuated a lot in the filter. The transistor T4 and the capacitor 330nF lower the output impedance, minimizing the noise that the signal wire can collect for coupling with the power supply wire and with external disturbances. C12 and R13 are also a third low pass cell that enlarges the pulse and paves its tip. The pulse of this output (DC coupled and without undershoot) is also perfect for the costly MCA hardware equipment, of ancient design. R9, R10, C10 and C11 form the "Pulse shaper" that broadens the pulse to over 100 uS to increase the resolution of rows and slows its rising edge to minimize noise due to the "ringing" R8 and C9 form the "Pole-Zero Cancellation", well described in the literature, which eliminates the "Undershoot" and produces a pulse that goes to zero in the shortest possible time. The diode D6 prevents that the voltage goes negative and protects the base of the transistor. To positive voltage limit is accomplished by the transistor base emitter junction. In addition the resistors R8, R9 and R10 limit the current to levels absolutely safe, even if C8 go shorted by sending all the high voltage to the transistor, this would not break anyway.
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You are Einstein man. thank you.
