Filtering protection circuit based on CAN bus driving chip

Abstract

The invention relates to a filtering protection circuit based on a CAN bus driving chip, and belongs to the technical field of aviation electrics. On the basis of the CAN bus isolation driving circuit, two stages of protection circuits are added, the first-stage protection circuit is surge protection, the second-stage protection circuit is electrostatic protection, and on the basis, a chip common mode inductor and a common mode capacitor are added for protection, so that the anti-interference capability of the circuit can be greatly improved. Wherein a transient suppression diode and a bidirectional electrostatic protection diode are adopted as CAN bus interface protection devices, the reliability of the circuit is improved through series-parallel resistor current limiting, a CAN bus is filtered through a winding chip inductor and a common-mode capacitor, and a two-stage protection circuit is formed; the circuit is small in number of components, high in reliability, simple in parameter selection, wide in application range and high in environment applicability, and has typical popularization value.

Description

technical field [0001] The invention belongs to the field of aviation electrical technology, and in particular relates to a filter protection circuit based on a CAN bus driver chip. Background technique [0002] The CAN bus was first used in the automotive industry, using differential signal transmission to avoid signal reflection and interference. As the high performance and reliability of the CAN bus are gradually recognized, it has been widely used in medical equipment, ships, aviation and other industries. Changes in the application environment have brought about harsher working conditions, especially when used in the aviation field. Due to the influence of complex airborne conditions, strong surge interference voltage may be introduced on the bus, causing damage to the internal chip of the CAN bus module. At the same time, it may affect the function of the entire CAN communication link and affect the completion of system tasks. In order to improve system reliability, a...

AI Technical Summary

Problems solved by technology

Changes in the application environment have brought about harsher working conditions, especially when used in the aviation field, affected by complex airborne conditions, strong surge interference voltage may be introduced on the bus, causing damage to the internal chip of the CAN bus module At the same time, it may affect the function of the entire CAN communication link and affect the completion of system tasks. In order to improve system reliability, it is necessary to add a filter protection circuit to the CAN bus communication interface

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