1、 Overview

Industrial power systems often face transient surge threats such as lightning strikes and inductive load switching, and traditional protection schemes have response delays or power bottlenecks. This article is based on the working principle of TVS (Transient Voltage Suppressor), analyzing the performance advantages of Huaxuanyang Electronics‘ SMDJ series (packaged as SMC) at a peak pulse power of 3kW, and comparing it with competitors based on measured data to provide engineers with a low clamping voltage and high reliability surge protection design strategy.   

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2、 Main text

1. The core challenge of industrial power surge protection

-Instantaneous energy threat: Lightning strikes (IEC 61000-4-5 standard) can generate 10/700 μ s waveforms and 6kV voltage, requiring TVS to have a μ s level response speed.   

-Power dissipation requirement: When an inductive load is disconnected (such as motor control), surge energy can reach the joule level and needs to be absorbed by the TVS without damage.   

-Space and cost constraints: Industrial equipment requires small packaging (such as SMC) and maintenance free design.   

2. Engineering analysis of key parameters

Taking the Huaxuanyang Electronics SMDJ series as an example (with parameter range covering 5.0V-220V applications):

-VBR (breakdown voltage): 6.4-272V, must meet:

VBR_min>1.2 × V_operating (maximum operating voltage of the system)

-VC (clamp voltage): 9.2-356V, determines the peak voltage that the protected device can withstand.   

-IPP (peak pulse current): 8.4-326A, should be greater than the expected surge current value.   

-Peak pulse power: 3kW (10/1000 μ s waveform), verified according to the energy formula:

E=VC IPP t_pulse (t_pulse is the pulse width)

Example: When 100A surge, 20 μ s pulse width, and VC=50V, E=0.1J<<3kW × 1ms=3J (sufficient safety margin)

-TJ (junction temperature): -55-150 ° C, covering industrial grade temperature requirements.   

3. Objective parameter comparison with brand A

Difference explanation:

-Under the same IPP, Huaxuanyang VC is 11.6% lower, reducing the stress on the subsequent circuit;   

-Peak pulse power is increased by 20%, enhancing the ability to withstand single surges;   

-TJ has an upper limit of 25 ° C and is suitable for high-temperature environments (such as motor control cabinets).   

4. Application scenario performance verification

Scenario 1: AC/DC power input protection (220VAC system)

-Surge condition: 6kV/3kA combined wave (IEC 61000-4-5).   

-Selection: SMDJ220A (VBR=242-267V, VC)= 356V@326A ）.   

-Actual test results:

-Hua Xuanyang: Clamping voltage ≤ 350V, parameter drift<5% after 3 impacts;   

-Brand A: The clamping voltage reaches 395V, and after 3 impacts, the VBR deviates by 8%.   

Scenario 2: 24V PLC power bus protection

-Challenge: Multi node parallel connection leads to an increase in accumulated capacitance, and TVS requires low leakage current (IR).   

-Hua Xuanyang Plan: SMDJ26A (VBR=28.9-31.9V, IR=1 μ A @ 25 ° C)

-Power consumption comparison:

System standby power consumption=number of IR V_operating nodes

At 50 nodes, the standby power consumption of Huaxuanyang is 1 μ A × 24V × 50=1.2mW, which is 76% lower than brand A (IR=5 μ A).   

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3、 Conclusion

The Huaxuanyang Electronics SMDJ series achieves surge protection in industrial power supplies with a peak pulse power capacity of 3kW, low-temperature drift VC characteristics (more than 10% lower than competitors), and a 150 ° C junction temperature capability

1. The clamping voltage is reduced to improve the lifespan of the subsequent devices;   

2. Enhanced high-temperature stability to adapt to harsh environments;   

3. Optimize leakage current to save system standby energy consumption.   

Applicable scenarios: High frequency surge risk systems such as frequency converters, servo drives, and communication power supplies.   

>Note: The specific selection needs to be verified with the measured surge waveform. The data in this article is based on IEC standard testing conditions.