Automotive-compliant photorelay for 400V battery-related control systems

Toshiba Electronics Europe GmbH has introduced a high-voltage transistor output photorelay for 400V automotive battery-related control systems. Housed in a compact SO12L-T package, the TLX9150M produces a minimum breakdown voltage (VOFF) of 900V with a maximum reaction (TON/TOFF) time of 1ms. This is crucial for control-sensitive applications such as battery and fuel-cell control and BMS for monitoring voltages and detecting mechanical relay sticking and ground faults.

The device consists of an IR emitting diode optically coupled to a photo-MOSFET, providing electrical isolation between the primary (control) side and the secondary (switch) side, allowing safe switch control across varying ground potentials. The trigger current (IFT) is more than 3mA, which minimises system energy consumption. Also, this device's off-state current (IOFF) is just 100nA (max) at ambient temperature, drawing minimal power while inactive. The IR LED has a forward current (IF) rating of 30mA, while its photodetection element has an on-state current (ION) rating of 50mA at ambient.

Also, the TLM9150M is housed in the new SO12L-T package with a space-saving form factor of 7.76mm × 10mm × 2.45mm, 25% smaller than the company's existing package SO16L-T. This helps to miniaturise the battery unit and allows cost reduction. The two package sizes' pin pitch and layout are the same, allowing a common circuit board pattern design. This normally-open (1-Form-A) device exhibits 8mm (min) creepage and clearance distances and 0.4mm (min) insulation thickness, confirming effective isolation even in operating temperatures ranging from -40C to +125C, and is fully compliant with the AEC-Q101 and IEC 60664-1 standards.