ETC (electronic toll collection) system awakening circuit applicable to national standards

Abstract

The invention discloses an ETC (electronic toll collection) system awakening circuit applicable to national standards, relating to the integrated circuit technology. The circuit comprises an amplifying circuit, an oscillator, a reference source circuit and a digital processing module, wherein the amplifying circuit is connected with the output of a detector, and used for pre-amplifying input signals of the detector, then outputting the input signals to the digital processing module; the oscillator is used for producing clock signals and then outputting the clock signals to the digital processing module; the reference source circuit is used for producing reference current and reference voltage, then providing the reference current and the reference voltage to a pre-amplifying circuit and the oscillator; and the digital processing module is used for judging whether the input signals of the amplifying circuit are continuous 6-17 signals (10 KHz-25 KHz) according to the clock signals input by the oscillator, if so, outputting an awakening pulse. The circuit disclosed by the invention has the advantages of low power consumption, moderate sensitivity, strong PVT (process, voltage, temperature) change resistance capacity, and the like.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, and is a wake-up circuit for an electronic toll collection system (ETC) applicable to national standards. Background technique [0002] The traditional model of car toll booth charging is that the car stops after passing through the toll booth to pay the toll. This mode consumes the driving time of the car and affects the efficiency of road transportation. [0003] An intelligent wireless electronic toll collection system (Electronic Toll Collection, ETC) can solve this problem. This system needs to install an on-board wireless charging unit (On Board Unit, OBU) with the function of receiving and transmitting radio frequency signals at the corner of the car window, and set up a roadside unit (Roadside Unit, RSU) at the toll booth. When the car passes through the toll booth, the roadside unit communicates with the on-board unit OBU through radio frequency signals, and automatically d...

AI Technical Summary

Problems solved by technology

[0015] At present, most wake-up circuits are built with discrete devices or integrated components. The stability and consistency of the wake-up circuit realized in this way are not enough, and at the same time, the volume is large and the cost is high.

In addition, the current power consumption of most wake-up circuits is on the order of 10 μA. In order to maintain the standby time of the OBU unit for several years, a large-capacity, high-performance battery power supply is required, which increases the cost and volume of the entire ETC system.

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