Dual stage Op Amp Gain distribution question

Thread Starter


Joined Oct 4, 2009
I have an LMV 722M op amp that i use as an amplifier for an microphone and photo diode.
On this link http://www.grozeaion.com/hsp/high-speed-photography
i need to modify the circuits (Sound Trigger and Light/Dark Trigger) so that the second stage of the LMV 722M will not be used as "set" threshold level. It will be used as an second stage amplifier.
These sensor should detect low/high sounds (water drops/ popping balloons) and low/high light level.
I'm thinking that first stage must have a constant value and the second one variable.

Do you think that the gain distribution between the two stages in the attached picture is ok?


PS: The Vcc of the circuits will be 5V(it is provided by an digital output of the ATmega328) and the output of the sensor will be the input for one analog input of the same microcontroler