Low-capacitance large-surge protective circuit

Abstract

The invention relates to a low-capacitance large-surge protective circuit. The low-capacitance large-surge protective circuit is composed of 2n (n is an integer larger than or equal to 2 and smaller than or equal to 16) capacitance-reducing diodes, two low-voltage transient voltage suppressors (TVS) and two bothway discharge tubes. Negative poles of the capacitance-reducing diodes from the first to the nth are connected with one end of a first bothway discharge tube and are connected with a positive pole of a first low-voltage TVS and a negative pole of a second low-voltage TVS. Positive poles of the capacitance-reducing diodes from the first to the nth are respectively connected with lines from a line 1 and a line n. Positive poles of the capacitance-reducing diodes from the (n+1) th to 2nth are connected with one end of a second bothway discharge tube and are connected with a negative pole of a first low-voltage TVS and a positive pole of a second low-voltage TVS. Negative poles of the capacitance-reducing diodes from the (n+1)th to 2nth are respectively connected with the lines from the line 1 and the line n in sequence. The low-capacitance large-surge protective circuit overcomes the shortcomings that needed electronic components are large in amount, various in kind and complex in wiring, and occupied space in a printed circuit board (PCB) is large. Meanwhile, the low-capacitance large-surge protective circuit is simple in wiring, and has a low capacitance, low clamping and large surge protection ability, and has the advantage that a differential mode and a common mode are highly integrated.

Description

technical field [0001] The invention relates to the field of semiconductor overvoltage protection devices, in particular to a low-capacity large surge protection circuit, which is an emergency protection circuit used to limit overvoltage without cutting off the circuit. Background technique [0002] With the increase of the communication rate, the protection requirements of the data communication interface are getting higher and higher. The protection schemes that can meet the reliability test standards such as K20 and K21 often involve more protection components and larger PCB space. The situation that the main control IC chip of the circuit is burned due to the matching difference between the protection components occurs frequently. [0003] There are many components that can be used for surge protection, such as Thyristor, GDT, MOV, transient voltage suppressor (Transient Voltage Suppressor, TVS) and so on. For example, the patent application CN 201210172902.4 uses elect...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the defects in the prior art that there are a large number of required electronic components, various types, complicated wiring, and large PCB space occupation, and provide an integrated low-capacitance surge protection circuit for the protected system. Not only can it avoid damage to the protected system by transient voltages such as surges and ESD, but it also has the advantages of simple wiring, low capacitance, low clamping, large surge protection capabilities, and highly integrated differential common mode

Images