Switch detection circuit compatible with high and low levels

Abstract

The invention discloses a switch detection circuit compatible with high and low levels, which comprises a detection circuit and comparator circuits, the comparator circuits represent level value signals generated by the detection circuit in a binary manner, and the comparator circuits comprise a first comparator circuit, a second comparator circuit and a third comparator circuit, the first comparator circuit and the second comparator circuit are connected in parallel and then connected with the input end of the third comparator circuit, a Vi signal of a level value is generated after the switching value is input into the detection circuit, and a switching true value OH and a switching true value OL are output after the Vi signal of the generated level value passes through the first comparator circuit and the second comparator circuit respectively. And the switch truth value OH or the switch truth value OL is input into the third comparator circuit to generate a switch truth value O. Through the arrangement of the detection circuit and the comparator circuits, the compatibility of high and low levels is realized, the increasingly complicated and diversified use requirements are met with few interface resources, hardware or BOM versions are reduced, and the cost is saved.

Description

technical field [0001] The invention relates to the technical field of circuit detection, in particular to a switch detection circuit compatible with high and low levels. Background technique [0002] Switch detection is usually carried out by ordinary I / O sampling, as a digital quantity processing, there is only one level at a certain time, and the MCU has determined the effective level at the beginning of the design: 1 or 0. In use, the switch has three states of pulling up high level "+", pulling down low level "-" and disconnecting "NC". In use, "+" and "-" indicate signal input, and NC indicates input stop. Currently If the detection and sampling circuit recognizes "+", but cannot distinguish between "-" and "NC", and cannot achieve "+" and "-" level compatibility, in order to achieve high level and low level compatibility, it is necessary to change the internal ECU For hardware, the change cycle is very long. Changing the ECU hardware for the realization of high-level...

AI Technical Summary

Problems solved by technology

In use, the switch has three states of pulling up high level "+", pulling down low level "-" and disconnecting "NC". In use, "+" and "-" indicate signal input, and NC indicates input stop. Currently If the detection and sampling circuit recognizes "+", but cannot distinguish between "-" and "NC", and cannot achieve "+" and "-" level compatibility, the existing high level and low level compatibility needs to be changed inside the ECU Hardware, the change cycle is very long, changing the ECU hardware for the realization of high-level and low-level compatibility will lead to multiple ECU hardware versions, high generation and management costs

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