A wide common-mode input range receiving circuit and method with fail-safe

Abstract

The invention relates to a wide common mode input range receiving circuit and method with failure protection. The present invention includes a pull-up and pull-down network, an input stage, an amplitude adjustment unit, and a duty ratio adjustment unit. The pull-up and pull-down network is sequentially connected through the input stage, the amplitude adjustment unit and the duty ratio adjustment unit, wherein the pull-up and pull-down network generates an input offset voltage, and the input The stage receives the input signal, the amplitude adjustment unit completes the signal amplitude adjustment, and the duty ratio adjustment unit completes the input signal duty ratio correction. The invention has input open-state and ground-state failure protection functions, an input stage circuit capable of receiving rail-to-rail common mode range signals and signal processing for this type of input stage circuit.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a wide common-mode input range receiving circuit and method with failure protection. Background technique [0002] Fail-safe circuitry is used to avoid erroneous output states caused by noise on the input or incorrect connections. When the input port signal is invalid, the output of the driver is set as required by the fail-safe circuit; when the input signal is normal, the fail-safe circuit does not affect the function of the core circuit. According to the requirements of the clock and data-driven product manuals of core key manufacturers, when there is no input driver or an open circuit occurs, the front-end terminal resistor fails or is short-circuited, the fail-safe circuit in the device must set the output terminal. [0003] Traditional fail-safe circuits are mainly implemented in two ways: signal detection or pull-up and pull-down network methods. Signal detection is to...

AI Technical Summary

Problems solved by technology

Signal detection is to generate control signals through input signal detection, which requires additional design of detection circuits, increasing design difficulty and chip area, and will bring unnecessary load to normal signal links and affect signal quality; in addition, detection module judgment errors will directly affect normal Signal transmission, seriously affecting system functions

The pull-up and pull-down network method is to generate bias voltage through the pull-up and pull-down network. The structure of the pull-up and pull-down network method is simple and easy to implement. However, the traditional pull-up and pull-down network method mostly focuses on the failure protection of the input open state, and cannot protect the input ground state; the bias voltage method will generate DC offset, although the mismatch is a weak driver compared to the normal input signal, the offset will be significantly amplified during high-frequency signal transmission, affecting the signal quality, and the signal needs to be conditioned

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