ADC_numeratore_PGA

#define ADC_numeratore_PGA   1

Coefficients for reading nodes. Ri is in series to the source noise to measure and to RA, that is in series to the buffer and connected to RB from buffer to GND. We now use the LMP7702 as input buffer. It is a MOS input OA and does not show inpt current. Its input offset is quite negligible, but we measure it since the ADC contribution sums to it. Let's call it Vof. The voltage Vi to mesure is therefore: Vi= (Ri +RA+RB)/RB (Vm - Vof), where Vm is the voltage read from the ADC when the input is connected. Vi= Vm - Vof + (Ri +RA)/RB (Vm - Vof). So the numerator to consider is Ri+RA while the denominator RB. A special case is when the detector bias is read since a further attenuator is put before RA: RAp in series to the source node to read and connected to RBp, from Rap to GND. If we call Ri'=RAp||RBp, then: Vb= (RAp+RBp)/RBp (Vm-Vof + (Ri'+RA)/RB(Vm-Vof)) Partizione 8.2k con 82k all'ingresso del buffer: 8.2 /82 =1 /10

Definition at line 50 of file Adc.h.