- Suitable for 800V automotive battery systems -

July 17, 2025

KAWASAKI, Japan–Toshiba Electronic Devices & Storage Corporation ("Toshiba") has launched an automotive photorelay[1], “TLX9165T,” in a 10pin SO16L-T package, that supports high voltage automotive batteries with an output withstand voltage of 1800V (min). Volume shipments start today.

Improved charge times and longer cruising ranges are essential for wider adoption of electric vehicles, and both require more efficient operation of battery systems. Battery management systems (BMS) realize efficient system operation by monitoring the battery charge status, and the insulation between the battery and the vehicle body that is essential for the safe use of high-voltage batteries. BMS that must handle high voltages use electrically isolated photorelays.

Energy storage systems (ESS), used to secure efficient operation of renewable energy, have also adopted a configuration similar to BMS; they handle the same high voltage as electric vehicles, and use electrically isolated photorelays.

While 400V battery systems are the mainstream in electric vehicles, growing demand for longer cruising ranges and faster charging will hasten the shift to 800V systems. Photorelays used in those battery systems must have a withstand voltage approximately twice the system voltage, which is 1600V or more for an 800V system. Toshiba’s new photorelay incorporates a newly developed high-voltage MOSFET with an output withstand voltage of 1800V (min), suitable for 800V systems.

The 10-pin SO16L-T package adopts a resin with a Comparative Tracking Index (CTI)[2] of 600 or more, putting it in material group I[3] of the IEC 60664-1[4] international standard, and the  pin configuration ensures a creepage distance of 7.5mm or more[5] on the light receiver side (Figure 1). These features are compliant with IEC 60664-1, and deliver an operating voltage of 1500V.

The pin pitch and pin configuration are the same as SO16L-T[6], allowing the common use of PCB pattern design.

Toshiba will continue to develop photorelay products suitable for battery systems in automotive applications and energy storage systems in industrial equipment, contributing to the safe operation of equipment.

Notes:

[1] Photorelay: The primary (control) side and the secondary (switch) side are electrically isolated. Switches connected directly to the AC line and switches between equipment that differ in ground potential can be controlled through insulating barriers.

[2] Comparative Tracking Index (CTI): IEC 60112[7] defines CTI as the maximum possible voltage before droplets of ammonium chloride solution on the surface of the insulating material cause tracking, under the given test conditions.

[3] Material group I: One of the classifications of molded materials in IEC 60664-1[4] refers to materials with a Comparative Tracking Index (CTI)[2] of 600 and more.

[4] IEC 60664-1: This standard specifies principles, requirements, and test methods for insulation coordination for systems up to AC 1000V or DC 1500V.

[5] A creepage distance of 7.5mm or more: The required creepage distance for an operating voltage 1500V, material group I, pollution degree 2 (the degree of pollution of the operating environment where electrical equipment is used: pollutants are entirely non-conductive, but could potentially be rendered conductive by condensation.)

[6] SO16L-T: The package used for Toshiba’s TLX9160T and TLX9152M.

[7] IEC 60112: An international standard that specifies testing methods for measuring the Comparative Tracking Index (CTI) of insulating materials. This standard is used to evaluate electrical breakdown (tracking) characteristics at the surface of solid insulating materials.

Applications

・Automotive equipment: BMS (battery voltage monitoring, mechanical relay sticking detections, ground fault detections, etc.)

・Industrial equipment: ESS

・Replacement of mechanical relays

Features

・Output withstand voltage: VOFF=1800V (min)

・Normally opened (1-Form-A) device

・Avalanche current rating: IAV=0.6mA

・High isolation voltage: 5000Vrms (min)

・AEC-Q101 qualified

・Compliant with IEC 60664-1 International Standard

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