900V 100mA photo-relay for 400V automotive batteries

Toshiba is aiming at 400V automotive systems with a 400V photo-relay that can handle 900V and ~30mA. Recommended maximum operating voltage is 720V.

900V 100mA photo-relay for 400V automotive batteries

Called TLX9150M, it measures around 10 x 8 x 2.5mm and can carry 50mA at 25ºC, 20mA at 105ºC and 10mA at 125ºC, or 1ms pulses of 150, 60 and 30mA respectively.

The package, SO12L-T has 8mm creepage and clearance. Insulation is at least 0.4mm thick and it has a CTI (comparative tracking index) above 600.


On the input side, 3mA is sufficient to turn on the output mosfets, although recommended forward current is between 5 and 20mA (30mA abs max). Recommended maximum output current is 50mA, and this can be alternating because the output switch is a back-to-back mosfet pair. On-resistance is a maximum of 400[ohm] at 125°C.


Off-state leakage is 1µA max from -40 to +105°C with 900V across the output, or up to 5[micro]A if the temperature is increased to 125°C.

On and off switching are both 1ms or less across the full -40 to +125°C with 10mA of drive if the output is loaded with 20k[ohm] to a 40V supply. It can also be much quicker, depending on device and drive current.

Compliance is to AEC-Q101 and IEC 60664-1.

Applications are foreseen in battery management systems: monitoring voltages, detecting mechanical relay sticking and detecting ground faults.

Find the TLX9150M photo-relay on this product page.

Steve Bush

Steve Bush is the long-standing technology editor for Electronics Weekly, covering electronics developments for more than 25 years. He has a particular interest in the Power and Embedded areas of the industry. He also writes for the Engineer In Wonderland blog, covering 3D printing, CNC machines and miscellaneous other engineering matters.

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