# High Voltage Isolation Measurement in EVs Using the VORA1150

**URL:** <https://forum.digikey.com/t/high-voltage-isolation-measurement-in-evs-using-the-vora1150/68778>\
**Category:** Relays\
**Tags:** vishay-semiconductor-opto-division, solid-state-relays-ssr\
**Created:** [May 13, 2026, 7:25am UTC](https://forum.digikey.com/t/high-voltage-isolation-measurement-in-evs-using-the-vora1150/68778 "2026-05-13T07:25:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Dimitrij](https://avatars.discourse-cdn.com/v4/letter/d/b3f665/32.png) [@Dimitrij](https://forum.digikey.com/u/Dimitrij)\
**Post date:** [May 13, 2026, 7:25am UTC](https://forum.digikey.com/t/high-voltage-isolation-measurement-in-evs-using-the-vora1150/68778/1 "2026-05-13T07:25:01Z")

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**INTRODUCTION**

Electric vehicles (EVs) rely on accurate **isolation measurement** to ensure driver safety and comply with functional safety standards (e.g., ISO 6469-1, ISO 26262). As EV battery voltages rise - often exceeding 800 V - the need for **high voltage switching solutions** in isolation monitoring circuits is growing.  
To meet this need, we are introducing our new **[VORA1150](https://www.digikey.com/en/products/detail/vishay-semiconductor-opto-division/VORA1150/26859915) 1500 V solid-state relay (SSR)**, which is specifically optimized for **isolation resistance measurement** in high voltage EV systems.

  

**ISOLATION MEASUREMENT IN EVs**

During normal operation or charging, an isolation monitoring device (IMD) checks the resistance between the high voltage battery system and chassis ground. If this isolation degrades or there is a short, the IMD must detect and report it to the battery management system (BMS) to trigger protective measures.  
A switching element - typically a **solid-state relay** - is required to connect the IMD to the HV+ or HV- rails during testing and isolate it afterwards.

  

**WHY USE A SOLID-STATE RELAY?**

Compared to electromechanical relays, SSRs are ideal for high voltage, high reliability automotive applications:

- **Fast switching** for real-time diagnostics
- **No mechanical wear** , enabling long life even with frequent test cycles
- **Silent and arc-free operation** , suitable for enclosed environments
- **Compact footprint** , allowing easy integration into power distribution units (PDUs) or BMS boards

  

**INTRODUCTION OF A NEW 1500 V SSR**

Our newly developed **VORA1150 solid-state relay** is designed specifically for EV isolation measurement applications. Key features include:

- **Rated voltage:** up to 1500 VDC
- **2.4 kV high pot pulse width:** 5 s
- **Current handling:** up to 50 mA
- **Avalanche current:** 0.9 mA
- **Leakage current:** \< 100 nA at 1500 V
- **Working voltage:** up to 1000 VDC
- **Fast switching time:** \< 250 μs
- **AEC-Q102 qualified** for automotive applications
- **Ambient temperature:** up to 125 °C

  

**CONCLUSION**

The VORA1150 solid-state relay offers the high voltage rating, low leakage, and fast switching needed for **safe and reliable isolation monitoring** in modern EVs.  
Its robust design and Automotive Grade qualification make it a dependable choice for designers looking to meet strict safety standards in high voltage applications.  
For more information or design support, contact our applications engineering team at [optocoupleranswers@vishay.com](mailto:optocoupleranswers@vishay.com), download the full VORA1150 datasheet or Vishay’s whitepaper: [80616HIGHVOLTAGEISOLATIOHNMEASUREMENTINEVSVORA1150.fm](https://www.vishay.com/docs/80616/highvoltageisolatiohnmeasurementinevsvora1150.pdf)