Opto Devices Extend to Fulfill Automotive, Harsh-Environment Apps

Why It Matters

These components enable more reliable, space‑efficient power switching in electric‑vehicle systems and high‑temperature test equipment, reducing board size and improving durability under extreme conditions.

Key Takeaways

• Toshiba launches TLX9920 photocoupler for automotive solid‑state relays
• TLX9920 operates –40 °C to 125 °C, 5 kV isolation, 0.6 ms turn‑on
• New photorelays rated 135 °C, 500 V isolation, voltage‑driven design
• SO6L package offers 8 mm creepage, meeting IEC 60664‑12 standards
• Devices target battery‑management, chargers, inverters, and high‑temp test equipment

Pulse Analysis

Optoelectronic isolation has become a cornerstone of modern automotive electronics, especially as electric‑vehicle architectures demand higher voltage handling and tighter space constraints. Traditional electromechanical relays add bulk and suffer from wear, prompting designers to adopt solid‑state solutions that eliminate ground loops and improve reliability. Toshiba’s latest offerings arrive at a time when automotive standards such as AEC‑Q101 are tightening temperature and isolation requirements, and manufacturers are seeking components that can survive the –40 °C to 125 °C range typical of vehicle under‑hood environments.

The TLX9920 photocoupler distinguishes itself with a photovoltaic output that directly drives MOSFET gates, removing the need for external discharge resistors and accelerating switching speeds. Its SO6L package provides over 8 mm of creepage distance, satisfying IEC 60664‑12 for 5 kV RMS isolation, while delivering a typical turn‑on time of 0.6 ms and turn‑off time of 0.1 ms. These characteristics make it ideal for battery‑management systems, onboard chargers, and inverter modules where fast, high‑voltage switching is critical. By integrating a control circuit on the receiver side, the device simplifies PCB layouts and reduces component count, a valuable advantage in densely packed EV power modules.

Complementing the photocoupler, Toshiba’s new voltage‑driven photorelays (TLP3407SRB, TLP3412SRB, TLP3412SRHB, TLP3412SRLB) push the temperature envelope to 135 °C, addressing the growing need for high‑temperature reliability in automotive semiconductor testers, probe cards, and burn‑in rigs. Their 500 V RMS isolation and built‑in input resistors free up board space, enabling more compact test fixtures. Together, these products signal a broader industry shift toward rugged, miniaturized optoelectronic switches that can meet the stringent demands of next‑generation electric vehicles and industrial power‑electronics applications.