Noise

The noise was measured on a single channel for different capacitances. Threshold was set to 900mV, the injected charge for 16%/50%/84% count rate was measured ... (crude S-curve)

The results are     ENC = 2240+42e-/pF for the negative amplifier

                           ENC = 1880+45e-/pF for the positive amplifier

The corresponding working point thresholds (threshold set to 5x noise) are given in the plot below.

At 0/100/200pF we can use threshold of 1.5/5/9.5fC.