Photovoltaic output photocoupler for automotive launched

Toshiba Electronics Europe GmbH offers a new photovoltaic output photocoupler with an enhanced open-circuit voltage. The new device is mainly intended for use within SSR applications in automotive. However, it can also be employed in industrial applications like renewable energy.

In recent years, automotive applications have become more difficult, demanding safer, compact, and maintenance-free solutions with long lifetimes. For this reason, SSRs are increasingly replacing traditional mechanical relays. The lack of physical contacts ensures reliability and silent operation in applications such as electric mobility.

The new TLX9910 photocoupler is ideal for gating high-voltage power MOSFETs commonly employed in solid-state relays. This combination allows high-voltage, high-current switching, which is difficult to achieve with integrated photorelays.

Automotive BMS need considerable power handling capabilities within MOSFETs, and suitable devices tend to need a higher gate-drive voltage. Many existing photovoltaic couplers provide a limited selection of suitable MOSFETs due to their lower output voltage, needing a workaround with two photovoltaic couplers connected in series.

However, the new device offers an open voltage (VOC) of 13.5V – almost double that of existing devices. The choice of compatible MOSFETs (without a workaround) is greatly increased. Using a single device reduces the component count, thereby reducing the solution's size, weight and cost.

As the photovoltaic coupler is based upon PDA, electrical energy is generated as a result of light from the input side LED. The coupler, therefore, serves its own power supply, eradicating the necessity for an external power source.

The device is housed in a small surface-mount four-pin SO6 package measuring 3.7mm × 7mm x 2.1mm. It can operate at temperatures of -40C to +125C and offers 3750Vrms of isolation from input to output.