S1223 Series PIN Photodiodes. The S1223 series, from Hamamatsu Photonics, are a group of silicon PIN photodiodes. They are for visible and IR applications, offering precision photometry. The S1223 series have high sensitivity and a high speed response. They offer low capacitance with high reliability. Suitable applications include optical measurement equipment and analytical equipment.. Features of the S1223 PIN photodiodes: TO-5 package Through-hole mounting Operating temperature: -40 to +100 °C High sensitivity High reliability