Hardware diagnostic protection circuit

Abstract

The invention discloses a novel hardware diagnosis protection circuit. The novel hardware diagnosis protection circuit comprises an ECU1 communication circuit and an ECU2 power circuit, an audion Q1 of the ECU1 communication circuit is controlled by a drive signal Vin, and a Q1 collector electrode is connected to the ECU2 power circuit. The novel hardware diagnosis protection circuit is characterized in that the Q1 collector electrode is connected to a protection circuit; the protection circuit consists of a main protection circuit and a limiting value protection circuit, the main protection circuit comprises Q2, Q3 and R4, wherein an emitting electrode of the Q2 is connected to the collector electrode of the Q1, a base electrode of the Q2 is connected to a collector electrode of the Q3, a base electrode of the Q3 is connected to the R4, and the other side of the R4 is connected to the input end of the ECU1 communication circuit; the limiting value protection circuit comprises voltage-regulator tubes Z1, R5, R6 and Q4, the voltage-regulator tubes Z1, R5 and R6 are connected in sequence, the input end of the voltage-regulator tube Z1 is connected to the collector electrode of the Q2, and a base electrode of the Q4 is connected to the R5 and the R6, and a collector electrode of the R4 is connected to a base electrode of the Q1. The pure hardware circuit disclosed by the invention has the advantages of low cost, high reliability and quick short-circuit protection actions.

Description

technical field [0001] The invention relates to the technical field of automotive electronic functional circuits, and more specifically relates to a hardware diagnosis and protection circuit. Background technique [0002] In automotive electronics, communication is often required between ECUs (Electronic control unit), such as figure 2 As shown, the driving signal Vin-5V in ECU1 drives the triode Q1, and the triode Q1 is saturated and turned on or off, and the V-diag signal level will be pulled down or maintained at a high level. ECU2 can detect V-diag signal level To determine the level of the driving signal Vin-5V in ECU1. [0003] When the drive signal Vin-5V in ECU1 is output high, it drives the triode Q1, and after the triode Q1 is saturated and turned on, the V-diag signal level will be pulled down, and ECU2 can judge the V-diag signal level by detecting the low V-diag signal level. The drive signal Vin-5V inside ECU1 is at high level. Similarly, when the drive sign...

AI Technical Summary

Problems solved by technology

[0006] 1. The use of single-chip microcomputer control or the use of an I / O port signal V-detect of one more single-chip microcomputer may increase the cost of the project

[0007] 2. There is usually some delay in the detection and protection of the single-chip microcomputer. When an abnormal situation occurs, the hardware circuit may be damaged before the detection or protection action of the single-chip microcomputer is completed.

[0008] When some customers require high safety of automotive electronic functions, the software protection measures are usually considered to be not reliable enough because of problems such as software runaway and abnormal reset of the single-chip microcomputer.

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