Photovoltaic-output photocoupler for isolated solid state relays

Toshiba Electronic Devices & Storage Corporation has launched TLP3910, a photovoltaic-output photocoupler housed in a thin SO6L package, suitable for driving the gates of high-voltage power MOSFETs used as isolated solid state relay (SSR) function. Volume production shipments start today.

An SSR is a kind of semiconductor relays that has a photo triac, a photo transistor or photo thyristor as its output device. It is suitable for applications for performing ON/OFF control of large currents.

A photovoltaic coupler is a photorelay with its optical devices but without the MOSFET used to perform switching functions. In configuring an isolated SSR, high-voltage, large-current switching, which photorelays handle with difficulty, can be implemented easily by combining a photovoltaic coupler and a MOSFET.

Driving a high-voltage power MOSFET with a gate voltage of 10V or higher, requires connecting two of Toshiba's current product, the TLP3906, in series, as it has a low open voltage. In contrast, the new TLP3910 has a minimum open voltage of 14V, double that of TLP3906, and only one is required to drive the gate of a high-voltage power MOSFET. This contributes to part-count reduction.

Improvement to the built-in discharge circuit has realized a typical turn-off time of 0.1ms, about 1/3 that of TLP3906 and about 1/30 that of TLP191B, and this delivers higher speed operation.

TLP3910 is Toshiba's first photovoltaic coupler to feature a minimum isolation voltage of 5000 Vrms while maintaining the basic performance of the current products, TLP191B and TLP3906. This allows use in industrial equipment driven by AC400V systems. The scope of application has also been extended by its high-temperature operation of 125°C.

Provided by Toshiba Corporation