Designed for use in measuring instruments, as MOSFET gate drivers or the replacement of mechanical relays, Toshiba Electronics Europe has announced the TLP3905 and TLP3906 photovoltaic couplers. The devices expand application possibilities by increasing the maximum operating temperature to 125°C and increasing the minimum isolation voltage to 3750Vrms.
Since the structure of a photovoltaic coupler is a photorelay without a MOSFET chip, users can create an isolated relay by combining the coupler with an external MOSFET of their choice. This enables the user to realise larger voltages and currents and exceed the capabilities of existing photorelay products. The TLP3905 and TLP3906 couplers also provide a minimum short circuit current of 12μA and minimum open voltage of 7V.
Integrating a control circuit for releasing the MOSFET gate charge, the TLP3906 ensures a turn-off speed of 0.3ms (approximately one third the turn-off speed of the TLP3905). The TLP3906 also guarantees a minimum LED trigger current IFT (max) of 3mA. This ensures low power dissipation of LED current.