Surge protection circuit

• Main Authors: LUO XUCHENG, HU JIANWEI, CHENG JIANTAO
• Format: Patent
• Language: Chinese; English
• Published: 01.02.2019
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention discloses a surge protection circuit, and the circuit comprises a surge detection circuit, an N-type switching tube M0, P-type switching tube S1, S2, ..., Sm and a control circuit, whichare all connected between a charging voltage input end VIN and the ground. The surge protection circuit is formed by the series connection of n diodes and one resistor R0, wherein there are y Zener diodes in reverse series connection and n-y diodes in forwarding series connection. A second pin of M0 is grounded, and the first pin is connected with the VIN. R0 is connected between the second pin of M0 and a drive pin. Zj is connectd with the second and first pins of Sj, wherein j=1, 2, ...,m, and n>m>=1. The control circuit detects the size of a surge current IIN flowing through M0, and sets different threshold values which meet the condition: IN1<IIN2<...<IINm. If IIN>IINj, the control circuit controls the connection of the P-type switching tube S1, S2, ..., Sj. The circuit achieves the surge protection of a char