In fields such as industrial automation (motor drive/industrial robots), transportation infrastructure (charging piles/on-board electronics), security systems (surveillance cameras/access control systems), and energy storage devices (BMS/off-grid controllers), DC48V power supplies are widely used due to their safety ultra-low voltage (SELV, ≤60V) characteristics.

Based on standards such as IEC 61000-4-2, EN 61000-4-2, GB/T 17626.2, IEC 61000-4-5, EN 61000-4-5, and GB/T 17626.5, Leimao Electronics customizes and develops a differential common mode surge protection scheme with polarity reverse connection protection. Avoid equipment malfunctions caused by static electricity, surges, reverse polarity connections, etc.

Core solution architecture: Three-level protection progresses layer by layer

l The Thunderbolt uses TVS devices with a voltage accuracy of ±5% and a response time of less than 1ns to provide precise overvoltage protection for the back-end circuits. It can clamp the peak value of 8/20μS surge to ≤93.6V (typical value), preventing the breakdown and failure of precision components such as the back-end MCU and sensors due to overvoltage. Supports multiple power level selections ranging from 400W to 15kW, suitable for different risk scenarios both indoors and outdoors.

The rear stage of the TVS diode is connected in series with a PMOS transistor or a low-dropout Schottky diode for polarity reverse connection protection. The power loss of the low internal resistance PMOS transistor is reduced by 60% compared with traditional diodes, making it suitable for high-power systems above 20A. A low VF Schottky diode is connected in parallel near the chip end for negative voltage surge protection.

The l thunderbolt provides an efficient discharge path for inrush current by connecting a ceramic gas discharge tube in parallel between GND and PE. If the product involves insulation withstand voltage testing, the rated voltage of GDT can be increased to simultaneously meet the requirements of withstand voltage and surge protection.

A low VF Schottky diode is connected in parallel at the power input end of the chip to provide a fast discharge path for negative pressure interference.

雷卯针对DC48V电源防护推荐料号表
类别	型号	参数	电流IPP	封装	防护功能
TVS	SMAJ58CA	58V,400W,双向	4.3A	SMA	差模浪涌防护
TVS	SMBJ54CA	54V,600W,双向	6.9A	SMB
TVS	SMCJ58CA	58V,1500W,双向	16.1A	SMC
TVS	SMDJ58CA	58V,3000W,双向	32.1A	SMC
TVS	LM1K58CC	58V,双向,2KV防护	1KA	SMC
TVS	SM8S60CA	60V,6600W,双向	68.2A	DO-218AB
PMOS	LM5D28P10	-100V,RDS(ON) < 55mΩ @ VGS=-10V	-28A	DFN5*6-8	极性反接保护
PMOS	LM5D40P10	-100V,RDS(ON) < 57.5mΩ @ VGS=-10V	-40A	DFN5*6-8
PMOS	LM5D50P10	-100V,RDS(ON) < 28mΩ @ VGS=-10V	-50A	DFN5*6-8
肖特基	SS110	100V,VF=0.85V	1A	SMA	负压浪涌防护
肖特基	SS210LA	100V,VF=0.65V	2A	SMA
肖特基	SS210B	100V,VF=0.85V	2A	SMB
肖特基	DSK310	100V,VF=0.85V	3A	SOD-123FL
肖特基	DSK315	150V,VF=0.95V	3A	SOD-123FL
肖特基	DSK320	200V,VF=0.95V	3A	SOD-123FL
肖特基	SS310A	100V,VF=0.85V	3A	SMA
肖特基	SS315A	150V,VF=0.95V	3A	SMA
肖特基	SS320A	200V,VF=0.95V	3A	SMA
肖特基	SS320B	200V,VF=0.95V	3A	SMB
GDT	2R090-5S	90V,1PF,双向	5KA	SMD 5.5*6	共模浪涌防护
GDT	2R150-5S	150V,1PF,双向	5KA	SMD 5.5*6
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