Hi,
Wondered if someone could give me a theoretical answer to a little problem, as I am having difficulty in getting accurate voltage test readings to prove the point.
I'm using a couple of op amps LF356 and TL084 to amplify the signal up to +1.7 0 -1.7 and then offsetting it to produce 0 to +3.4v. (sensor input - very slow change)
The testing power supply is nominally - + 5v , but would like to reduce this to a +5v only in the final version by using an ICL7660 converter - however with the load of 12 ma the output of this chip drops to 4.43volts - confirmed by its datasheet.
What I cannot accurately measure when using the 7660, is if there is any difference on the signal being amplified when running at this lower voltage - is the reduced negative voltage supply actually reducing the gain of the signal ?
Also would it actually affect the lineararity of the signal ?
Similarly if I was to pop a diode in the +5v rail to drop it to 4.4 volts would the gain be proportionally reduced ?
Will have to do that electronics theory course one day !
Thanks
Richard
Wondered if someone could give me a theoretical answer to a little problem, as I am having difficulty in getting accurate voltage test readings to prove the point.
I'm using a couple of op amps LF356 and TL084 to amplify the signal up to +1.7 0 -1.7 and then offsetting it to produce 0 to +3.4v. (sensor input - very slow change)
The testing power supply is nominally - + 5v , but would like to reduce this to a +5v only in the final version by using an ICL7660 converter - however with the load of 12 ma the output of this chip drops to 4.43volts - confirmed by its datasheet.
What I cannot accurately measure when using the 7660, is if there is any difference on the signal being amplified when running at this lower voltage - is the reduced negative voltage supply actually reducing the gain of the signal ?
Also would it actually affect the lineararity of the signal ?
Similarly if I was to pop a diode in the +5v rail to drop it to 4.4 volts would the gain be proportionally reduced ?
Will have to do that electronics theory course one day !
Thanks
Richard