I have an existing analog input circuit on a device that utilizes an op amp (TI LM2902) as a buffer. There is a reference voltage of 9V and the Op Amp is powered by 5V. The input signal to be read by the ADC originates at an off-board sensor.
I am wanting to make a new device with more inputs and re-use the existing circuit. The new device I am making does not have any need for 5V, so I am wondering if it is possible to raise the Op Amp supply voltage to 9V without affecting the ADC values? I want the A to D readings to be consistent between the two device.
My understanding is that the supply voltage just dictates the ceiling of the output voltage. Is this correct and the ADC values will be the same whether I power the op amp with 5 or 9 volts?