The PDM9107-CP-TTL is a sophisticated photon counting module that integrates a high-sensitivity, low-noise 29mm diameter photomultiplier, a fast amplifier-discriminator, and a low-power high-voltage supply. This combination of high-speed electronics and a fast photomultiplier with low dark counts allows for the achievement of a wide dynamic range. The module utilizes a positive polarity high-voltage supply to ensure maximum count rate stability even at very low light levels. Additionally, it features a mumetal cylindrical housing that offers a high level of immunity to external magnetic fields.

With a spectral range of 280-630nm, the PDM9107-CP-TTL is designed for optimal performance in various applications. Other versions, such as the PDM9107Q-CP-TTL, are available for those requiring extended UV sensitivity down to 160nm. The module's effective photosensitive diameter of 25mm facilitates efficient light collection, and its typical dark count of only 100 cps at 20°C provides an exceptional detection capability.

The photomultiplier high-voltage and discriminator threshold level are pre-set for optimal performance, allowing for straightforward photon counting operation by simply connecting to a +5V supply. The fixed pulse-width TTL output is fully compatible with the ET Enterprises MCS-CT3 multi-channel scaler/counter-timer. When used together, these units can be conveniently controlled and powered from a PC USB port, subject to the USB port's current limitations.