Calibration and Noise

Signal and noise resulting from internal calibration measurements with a nominal amplitude of $1\,\rm MIP$ ($22500\,\rm e$) are shown for both peak and deconvolution modes in tab. . No capacitive load was connected to the APV inputs. The noise figures obtained here still include a small contribution of the readout system. On the other hand, the internal calibration is known to produce signals which are larger than their nominal values (see section , p. ), thus resulting in a noise underestimation. Assuming that these effects approximately compensate each other, the numbers given here are compatible with the values obtained for a single APV25S1 (tab. , p. ). Thus, the APVMUX does not contribute significant noise.

Table: Internal calibration signal and noise measurements on an APV25S1 followed by the APVMUX.

Mode	Signal $\rm [ADC]$	Noise $\rm [ADC]$	SNR	Noise $\rm [e]$
Peak	72	1.10	65.5	344
Deconvolution	83	1.58	52.5	428