Small-Package, High-Power, Low-Clamping Snap-Back TVS: A New Benchmark for Industrial Automation and Robotics Protection

In critical scenarios such as energy storage systems, lithium battery management systems (BMS), and new energy vehicle electronics, equipment operates continuously under high voltage, high frequency, and long-term uninterrupted conditions. Transient overvoltage events such as lightning surges, load dump, and inductive load switching can easily cause breakdown and failure of core components such as the BMS main MCU, AFE sampling chips, and MOSFETs, directly leading to system shutdown, equipment damage, and even safety risks.

TVS devices with Snap-back characteristics are the optimal protection solution for such issues. Focusing on the core requirements of circuit protection, Shanghai Leiditech has independently developed and mass-produced Snap-back TVS devices featuring small packages, high power, and ultra-low clamping voltage. Their technical performance fully matches that of leading international brands such as Littelfuse, Vishay, and Semtech, providing highly reliable and cost-effective domestic alternative protection solutions for energy storage and BMS systems.

As the first line of defense in circuit protection, the low clamping voltage of a TVS is the core metric for evaluating its protection capability, directly determining the safety limit of downstream chips. Leiditech's Snap-back TVS, with its extremely low Vc value, ensures that core chips remain within their safe operating area during surge events, building a robust circuit protection network. The figure below shows the VI characteristic curve of Leiditech's Snap-back TVS.

I.Snap-Back TVS: Core of Precision Protection for Energy Storage and BMS

Under surge impact, the clamping voltage of a standard TVS continues to rise as the current increases, often exceeding the withstand voltage range of downstream sensitive chips, failing to provide truly effective safety protection.

Leiditech's Snap-back TVS features a unique negative resistance snap-back characteristic: after the device is triggered and breaks down, the voltage quickly drops to a lower holding voltage, discharging the surge current at nanosecond speed and clamping the voltage to an extremely low level, fundamentally preventing high-voltage stress from damaging core components.

Core protection advantages

1. Ultra-fast response: Nanosecond-level turn-on, quickly discharging high-energy transient currents such as lightning strikes and load dump.

2. Ultra-low clamping: After snap-back, the voltage is significantly lower than that of a standard TVS, greatly increasing the safety margin for chips.

3. No latch-up risk: Fast recovery after surge events, suitable for 7×24 hour continuous operation scenarios.

4. High reliability: Withstands repeated surges without failure, meeting automotive and energy storage grade long-term usage requirements.

II.Leiditech 13LM Series Snap-back TVS Product Introduction

To address the three core requirements of energy storage / BMS applications — high-density layout, high-power protection, and low residual voltage protection — Shanghai Leiditech has launched a 13kW Snap-back TVS in an SMC package. The three main models are the 13LM78CA, 13LM87CA, and 13LM102CA, achieving a unified combination of small size, high power, and low clamping voltage.

Analysis of Core Technical Advantages of the Product

1、  Ultra-low clamping voltage

Compared to the standard SMC package 8.0SMDJ78CA (clamping voltage 126V), the new 13LM78CA increases power by more than 60% while significantly reducing the clamping voltage to 100V. This means that under the same surge conditions, the voltage stress on downstream chips is reduced by more than 20%, with a notable improvement in safety margin.

2、Better power density

If the 13kW power rating is taken as the standard, traditional solutions would require the larger DO-218AB package (e.g., SM15S78CA, dimensions 15.5mm x 10mm). In contrast, the 13LM78CA, while maintaining the compact SMC package (8.0mm x 6.0mm), not only achieves the high power of 13kW but also has a much lower clamping voltage (100V) compared to the DO-218AB package solution (126V), truly achieving "small size, high power, and low residual voltage."

III.Three Major Application Values of Leiditech Snap-back TVS

1. Improve system reliability and extend equipment life

Effectively suppresses transient voltage peaks, reduces high-voltage impact damage to MCUs, AFEs, and MOSFETs, significantly lowers system failure rates, meets the 7×24h continuous operation requirements of energy storage / BMS systems, and extends the overall equipment lifespan.

2. Reduce design redundancy and optimize BOM cost

In traditional designs, to cope with the higher clamping voltage of TVS devices, engineers are often forced to select downstream MOSFETs or ICs with higher withstand voltage ratings and higher costs. A TVS with low VC provides a better solution, allowing engineers to select components with lower withstand voltage ratings, better performance, and lower cost, thereby effectively optimizing the overall BOM cost.

3.Meet more stringent standards and functional safety requirements

As functional safety requirements (such as ISO 26262) become increasingly stringent in the automotive and energy storage industries, circuit protection solutions must also meet higher standards. A TVS with low VC, with its excellent protection performance, helps system designs easily pass various stringent surge and transient tests, clearing obstacles for product certification and market access.

IV.Typical application scenarios

•Energy storage systems: Power conversion system (PCS), battery packs, BMS main control board, high-voltage sampling circuits

•New energy vehicles: Onboard BMS, OBC (onboard charger), DC-DC converter, 48V/800V high-voltage systems

• Industrial control: Photovoltaic inverters, industrial power supplies, high-voltage sensors, communication power supplies

• High-end electronics: Medical equipment, industrial robots, security monitoring equipment, smart grid devices

V.Leiditech Brand and Service Advantages

Shanghai Leiditech is a national high-tech enterprise specializing in ESD/EMC/overvoltage protection components, with its core technology benchmarked against Littelfuse, Vishay, and Semtech:

1. In-house technology: Core Snap-back TVS process independently developed, with performance comparable to international brands

2. Quality assurance: Passed AEC-Q101 automotive-grade certification and ISO 9001 and ISO 14001 system certifications

3. Service advantage: Full support from FAE team, providing one-stop services for selection, solution design, and testing verification

4. Delivery and cost: Domestic stock availability, more stable delivery lead times, higher cost-effectiveness, and clear advantages for replacement

5. Lab support: In-house EMC laboratory, providing customers with free testing for surge, ESD, and load dump

  As energy storage and BMS systems evolve toward higher safety, miniaturization, higher reliability, and lower cost, Snap-back TVS has become the standard solution for overvoltage protection.

With its core technology of small package, high power, and low clamping voltage, Shanghai Leiditech has developed industry-leading Snap-back TVS products, providing safer, more stable, and more competitive circuit protection solutions for new energy storage, automotive electronics, and industrial control, and has become the preferred partner for domestic replacement of international brands.

The parameters from one of the datasheets are attached as follows: