***Using +3.3V for REF_IN limits the SiPM amplifier bias voltages to a maximum of 165V. If greater variability is needed (up to +200V max), a separate +4V supply can be used for REF_IN, perhaps taken from the +5V rail via a voltage divider. | ***Using +3.3V for REF_IN limits the SiPM amplifier bias voltages to a maximum of 165V. If greater variability is needed (up to +200V max), a separate +4V supply can be used for REF_IN, perhaps taken from the +5V rail via a voltage divider. |