The TOSHIBA TLP558 consisits of a GaAAs light emitting diode and integrated high gain, high speed photodetector. This unit is 8-lead DIP package. The detector has a three state output stage that provides source drive and sink drive, and built-in schmitt trigger. The detector IC has an internal shield that provides a guaranteed common mode transient immunity of 1000V / s. TLP558 is inverter logic type. For buffer logic type, TLP555 is in line-up.