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

The new TLX9910 photocoupler is suitable for blocking the high-voltage power MOSFETs commonly used in solid-state relays. This combination enables the switching of high voltages and currents, which is difficult to achieve with integrated photorelays.

Automotive battery management systems (BMS) require MOSFETs with high power handling capabilities, and suitable devices often require a higher gate drive voltage. Many existing photocouplers offer a limited selection of suitable MOSFETs due to their lower output voltage, necessitating the use of two photocouplers connected in series.

However, the new TLX9910 offers an open-circuit voltage (VOC) of 13.5 V, almost double that of existing devices. This significantly increases the choice of compatible MOSFETs (without a workaround). Using a single device reduces the number of components and, therefore, the size, weight, and cost of the solution.

Because the photovoltaic coupler is based on photodiode arrays (PDAs), electrical power is generated by the light from the input-side LED. Therefore, the coupler is self-powered, eliminating the need for an external power supply.

The TLX9910 is housed in a small, 4-pin SO6 surface-mount package measuring only 3.7 mm × 7.0 mm × 2.1 mm. It can operate at temperatures from -40°C to +125°C and offers 3750 Vrms input-to-output isolation.

The new device is being mass-produced.

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