The C−Series low-light sensors from ON Semiconductor feature an industry-leading low dark-count rate combined with a high PDE. For ultrafast timing applications, C-Series sensors have a fast output that can have a rise time of 300 ps and a pulse width of 600 ps. The C−Series is available in different sensor sizes (1mm, 3mm and 6mm) and packaged in a 4-side tileable surface mount (SMT) package that is compatible with industry standard, lead-free, reflow soldering processes. An SiPM is formed of a large number (hundreds or thousands) of microcells. Each microcell is an avalanche photodiode with its own quench resistor and a capacitively coupled fast output. These microcells are arranged in a close-packed array.