TLP3341 Photorelay Photocoupler Toshiba TLP3341 Photorelay Photocoupler is a photo MOSFET optically coupled with an infrared light-emitting diode, in a USOP 4-pin package. TLP3341 Photorelay Photocoupler features a low output capacitance (COFF) of 0.7pF (typ.), 1.3pF (max). This gives the TLP3341 a fast on/off switching of a high-frequency signal, making it excellent for switching applications in high-speed testers.