High-Density Packaging Enabled by Automotive Chip Varistors as TVS Diode Replacements
Among these, protection against electrostatic discharge (ESD) is a critical factor that directly impacts the stability of in-vehicle communication systems.
To address these needs, TDK offers the AVRH Series of chip varistors as ESD protection components for automotive communication applications, providing a smaller and higher-performance alternative to conventional TVS diodes.
Differences Between TVS Diodes and Chip Varistors
Both chip varistors and TVS diodes are used for overcurrent and overvoltage protection, as well as for ESD and surge protection against various transient phenomena.
Chip varistors feature a polycrystalline ceramic structure primarily composed of zinc oxide, offering excellent resistance to high-energy surges. They are often designed with a multilayer structure, making them suitable for compact form factors in ESD protection applications.
In contrast, TVS diodes utilize a silicon PN junction structure, delivering ultra-fast response at the nanosecond level, which makes them ideal for ESD protection.
For more details, please refer to our previous article:
What is the difference between Zener/TVS diodes and varistors? Four comparison aspects to consider with regard to usage
Chip Varistors Prevent Damage of Electronics from Electrostatic Discharge
Features and Benefits of the AVRH Series Chip Varistors
The AVRH Series offers a lineup centered on compact 1005-size components and complies with the automotive standard AEC-Q200. These products deliver reliability equivalent to 1608-size automotive components and can safely replace conventional products. Development of the smallest model in the series, the 0603-size AVRH06C270KT200NA7, has also been completed.
Datasheets for pre-mass-production models are available for download at the bottom of this page.
- Ultra-compact 0603 size: Up to 80% PCB area reduction compared to conventional TVS diodes
- High-performance ESD protection: ±25 kV withstand capability ensures communication reliability
- Low capacitance: Suitable for high-speed communication lines
- High heat resistance: Maximum operating temperature of 125°C for automotive environments
- Cost benefits: Reduced component and assembly costs through miniaturization
Focused on ESD protection for automotive communication, the AVRH Series entered mass production in 2019 and is expected to ship over 300 million pieces per month by 2025. Previously, 1608-size chip varistors dominated automotive ESD protection applications, but the AVRH Series has achieved miniaturization to 1005 size without compromising performance.
The advantages of reduced PCB area and cost savings through miniaturization have led to increasing adoption by many customers.
Comparison between the AVRH-1005 mm type and the new 0603 mm type
The newly developed 0603-size product is designed to further reduce mounting area while maintaining the same performance level as the existing 1005-size product, offering a more compact solution.
ESD Robustness Evaluation
- IEC61000-4-2: Human Body Model (150pF / 330Ω) Test
Technical Details and Comparisons with Conventional and Competing Products
Varistor materials are generally classified into two categories: Bi-based (Bismuth) and Pr-based (Praseodymium).
Bi-based materials were developed and commercialized by Panasonic in the 1960s. Initially, large disk-type components were introduced for surge protection. Over time, miniaturization and SMD packaging were pursued to address electrostatic discharge (ESD) protection requirements.
Pr-based materials were developed and commercialized in the 1990s. These materials offer superior reliability and have been widely adopted in industrial and automotive applications where high reliability is essential.
1. Comparative Data: Chip Varistors
1-1. Comparison: Bi-based Varistors vs. AVRH Series
As shown in the figure, SMD varistors using Bi-based materials tend to degrade under ESD stress. Bi-based varistors exhibit relatively high resistance after varistor characteristics appear, making them prone to heat generation during ESD events.
Consequently, a single ESD application can cause significant degradation, making it difficult to maintain initial characteristics.
In contrast, the AVRH series maintains stable characteristics even under ESD stress.
The graph demonstrates that no degradation occurs up to 30kV under IEC61000-4-2 / HBM conditions.
ESD Robustness Evaluation
- ESD Conditions: 150pF / 330Ω
- Applied Voltage: ±2kV to 30kV
- Number of Discharges: 10 discharges per voltage level (contact discharge)
- Criteria: ΔV1mA / V1mA ≤ 10%
Varistor voltage before and after ESD application was measured to determine whether degradation occurred.
- ＜Company A＞
- Degradation occurred when the applied voltage exceeded 2 kV
- ＜AVRH10C220YT201MA8＞
- No degradation was observed up to 30kV
| Varistor Manufacturer | Automotive Application | Part Number | Varistor Voltage (V1mA) | Capacitance @C1kHz | Rating |
|---|---|---|---|---|---|
| Company A | LIN | - | 6.8 - 10.2V | 175pF | DC 5.6V max. |
| TDK | LIN | AVRH10C220YT201MA8 | 19 - 26V | 160 - 240pF | DC 16V |
Results
ESD Robustness
- Competitor A’s varistor exhibited characteristic degradation at 2kV, and the varistor voltage change rate showed up to approximately 50% degradation before and after 30kV application.
- TDK’s varistor showed no degradation even after application up to 30kV.
- This demonstrates that TDK’s varistors have superior ESD robustness, capable of withstanding higher voltages and greater electrical stress.
1-2. Comparison Between Competitor Varistors Using Pr-Based Materials and the AVRH Series
The following evaluation compares competitor B’s varistors, which use Praseodymium-based (Pr-based) materials, with the AVRH series.
Pr-based materials are generally stable under ESD stress and exhibit more consistent characteristics compared to Bi-based materials. However, some of competitor B’s varistors were observed to fail by short-circuit at 30kV.
In contrast, the AVRH series maintains its characteristics up to 30kV, with only minor variations observed.
ESD Robustness Evaluation (Varistor Voltage)
- ESD Conditions: 150pF / 330Ω
- Applied Voltage: ±2kV to 30kV
- Number of Discharges: 10 discharges per voltage level (contact discharge)
Varistor voltage before and after ESD application was measured to determine whether degradation occurred.
- ＜Company B＞
Some samples shorted at 30 kV
- ＜AVRH10C270KT150NA8＞
No degradation was observed up to 30kV
- <AVRH10C270KT350NA8>
No degradation was observed up to 30kV
| Varistor Manufacturer | Part Number | Varistor Voltage (V1mA) | Capacitance @C1kHz | Rating (DC max.) |
|---|---|---|---|---|
| Company B | - | 21.6 - 32.4V | 16.5 typ. | 18V |
| TDK | AVRH10C270KT150NA8 | 24 - 30V | 10.5 - 19.5 | 19V |
| TDK | AVRH10C270KT350NA8 | 24 - 30V | 24.5 - 45.5 | 19V |
Results:
- Some units of competitor B’s 15pF product experienced short-circuit failure under ±30kV application.
- TDK’s 15pF product (AVRH10C270KT150N) and 35pF product (AVRH10C270KT350N) showed no degradation under ±30kV application, demonstrating stable durability.
-------------------------------
2. Comparison Between Competitor TVS Diodes and the AVRH Series
TVS diodes used in automotive communication applications can withstand ESD up to 30kV in some cases; however, there are instances where short-circuit failures occur before reaching 30kV.
Unlike varistors, TVS diodes rarely exhibit gradual characteristic shifts—in most cases, they fail abruptly at a certain voltage level.
As shown in the evaluation graph below, the AVRH series demonstrates comparable ESD durability to TVS diodes (Competitor C), with only minor variations in characteristics.
ESD Robustness Evaluation (Varistor Voltage and Zener Voltage)
- ESD Conditions: 150pF / 330Ω
- Applied Voltage: ±2kV to 30kV
- Number of Discharges: 10 discharges per voltage level (contact discharge)
Varistor voltage before and after ESD application was measured to determine whether degradation occurred.
Acceptance Criteria: ΔV1mA / V1mA ≤ ±10%
-------------------------------
- ＜Company C＞
Confirmed that the diode shorted at around 28kV.
- <AVRH10C270KT350NA8＞
No degradation was observed up to 30kV.
- <AVRH10C270KT150NA8＞
No degradation was observed up to 30kV.
-------------------------------
| Manufacturer / Product | Part Number | Varistor Voltage / Zener Voltage | Capacitance @C1kHz | Rating (DC max.) |
|---|---|---|---|---|
| Company C / Diode | - | 26.2 - 32.0 V | 30 pF typ. | 24 V |
| TDK / Chip Varistor | AVRH10C270KT350NA8 | 24 - 30 V | 24.5 - 45.5 pF | 19 V |
| TDK / Chip Varistor | AVRH10C270KT150NA8 | 24 - 30 V | 10.5 - 19.5 pF | 19 V |
Results:
- According to AEC-Q200, 25kV is defined as the maximum level, indicating that the product demonstrates durability at the highest level.
-------------------------------
3. PCB Area Reduction Rate (0603/1005 Sizes)
Since the AVRH series is available in 1005 size, it offers a significant reduction in mounting area compared to TVS diodes—approximately 70–80% reduction is achievable.
Additionally, the 0603 size enables approximately 15% reduction in mounting area compared to the conventional 1005 size. When compared to TVS diodes, up to 85% reduction in mounting area can be achieved.
Applications
The “AVRH06C270KT200NA7” model is already being adopted in the following applications:
🚗 Automotive Microphones: Noise suppression for voice recognition and hands-free communication
📡 Telematics ECU: ESD protection for communication modules, ensuring stable data transmission
In addition to these, adoption is increasing for noise suppression and ESD protection in devices with strict space constraints.
The compact 0603 footprint minimizes PCB area, enhancing design flexibility and contributing to multifunctionality and miniaturization.
Future applications are expected to include ADAS-related modules, infotainment systems, in-vehicle sensor networks, and high-density control boards for electric vehicles
Web Exclusive:
Pre-Production 0603mm Size Automotive Chip Varistor Datasheet & Communication Line Design-in-Guide
[FILE NAME]tdk-apn-automotive-0603-chip-varistor.zip
[CAMPAIGN NAME]sample_campaign
For inquiries related to our products or sales, please contact us by filling the following Contact Form.
Request a free sample book by filling the following form. (until 27 February 2026）
Due to delivery policies and regulatory restrictions, delivery may not be available to businesses selling similar products or to certain regions. Thank you for your understanding.
Please click here for information on the list of distributors.
Related Links
