Self-checking circuit of analog-to-digital conversion circuit

Abstract

The invention relates to a self-checking circuit of an analog-to-digital conversion circuit. The self-checking circuit comprises a main control module, a first switch module and a second switch module, wherein the main control module outputs a PWM signal, generates a first reference voltage in a high level interval of the PWM signal, and generates a second reference voltage in a low level intervalof the PWM signal; the first switch module outputs a first standard voltage to the main control module in response to the high level of the PWM signal; the second switch module is used for outputtinga second standard voltage to the main control module in response to the low level of the PWM signal; the main control module determines the working state of the self-checking circuit according to a first difference value between the first reference voltage and the first standard voltage and a second difference value between the second reference voltage and the second standard voltage. The reference voltage and the standard voltage can be periodically checked, the situation that faults cannot be found in time due to failure of the self-checking function caused by accidental situations is avoided, and the reliability of the self-checking function of the analog-to-digital conversion circuit is improved.

Description

technical field [0001] The invention relates to the technical field of electronic circuits, in particular to a self-checking circuit of an analog-to-digital conversion circuit. Background technique [0002] Analog-to-digital conversion circuits are relatively common in controller design. In some occasions that require high reliability, such as industrial robots, it is required that the system can alarm in time when the analog-to-digital conversion circuit is abnormal, but conventional analog-to-digital conversion circuits cannot achieve this. This type of exception checking function. [0003] At present, the analog-to-digital conversion circuit with self-checking function usually reserves a channel N to scan a fixed external voltage reference value V1. The reference voltage value output by the channel N itself is V2, and the MCU compares V2 with the preset Compared with the set reference value V1, when the errors of V1 and V2 are within the expected range E, it indicates th...

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Problems solved by technology

[0004] In order to solve the fact that the circuit existing in the prior art can no longer work normally, but at this time the reference voltage value output by the verification channel N may be within the error range of the external voltage reference value, causing the system to fail to identify the fault, which in turn leads to the analog-to-digital conversion circuit The technical problem of the reliability of the existing problem, the present invention provides a kind of self-verification circuit of analog-to-digital conversion circuit

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