An ultrasonic sensor and a chip thereof

Abstract

The utility model discloses an ultrasonic sensor, including ultrasonic signal generation and emission module and ultrasonic signal reception and quantization module, the ultrasonic signal generation and emission module includes the crystal oscillator, direct digital frequency synthesizer, programmable pulse generator and amplifier that connect in proper order, the crystal oscillator still is connected with frequency doubler / frequency divider, and the frequency doubler / frequency divider is connected with ultrasonic signal reception and quantization module, the amplifier is two way analog amplifier, and is connected with emission channel TX0 and emission channel TX1 respectively, the utility model discloses a kind of chip, and the chip is made by the ultrasonic sensor.The utility model can produce multiple linear frequency modulation patterns, and also can realize amplitude modulation and phase modulation function, while the signal jitter introduced is extremely small, so the difficulty of receiving end signal processing can be significantly reduced, and the detection precision and anti-interference ability are improved by optimizing signal characteristics.

Description

Technical Field

[0001] This utility model relates to the field of ultrasonic sensor chip technology, and in particular to an ultrasonic sensor and its chip based on a crystal oscillator clock generator and a direct digital frequency synthesizer. Background Technology

[0002] Ultrasonic sensor technology is based on the piezoelectric effect, which converts electrical energy into sound energy. It utilizes the propagation and reflection characteristics of ultrasound waves in a medium to achieve distance measurement or object detection by accurately measuring the time of flight. Its structural design (such as matching layers and damping blocks) and signal processing circuits are designed to optimize transmission efficiency, receiving sensitivity, and measurement accuracy. Although some physical limitations exist (such as sound speed dependence and dead zone), its non-contact, cost-effective, and environmentally adaptable characteristics have led to its widespread application in numerous fields.

[0003] With the development of power electronics technology and semiconductor processes, more intelligent ultrasonic sensor chips have emerged. These chips not only integrate the transmission and reception of ultrasonic control signals, but also integrate microcontrollers and advanced digital signal processing algorithms. Thanks to the increased integration of ultrasonic sensor chips, multi-channel transmission and reception, and even the addition of receiving channels to monitor environmental interference, as well as signal processing capabilities, are now possible.

[0004] Traditional intelligent ultrasonic sensors used in fluid measurement have two channels each for transmitting and receiving, used to drive a pair of transducers. The transmitting channel TX0 emits a series of pulse signals to drive transducer TD0. Under the drive of the pulse signals, TD0 converts the received electrical energy into acoustic energy and emits it. The other transducer, TD1, receives the acoustic waves emitted by TD0, converts the acoustic energy into electrical energy, and transmits it to the receiving channel RX1. RX1 receives the signal and performs amplification, quantization, interpolation, and other processing. Conversely, the transmitting channel TX1 emits pulse signals to drive transducer TD1. TD1 converts electrical energy into acoustic energy and emits it. TD0 receives the acoustic wave signal, converts it into electrical energy, and transmits it to the receiving channel RX0. After transducers TD0 and TD1 each complete one transmission and reception cycle, the ultrasonic wave has propagated once in the fluid, both upstream and downstream. By calculating the time difference between the upstream and downstream propagation of the ultrasonic wave in the fluid, the current flow rate of the fluid can be calculated.

[0005] In the field of fluid measurement, the requirements for the accuracy and power consumption of measuring instruments are becoming increasingly stringent. That is, it is desirable for measuring instruments to have higher and higher accuracy and lower and lower power consumption, which brings considerable challenges to the design of front-end measuring sensor chips. Utility Model Content

[0006] The purpose of this invention is to provide an ultrasonic sensor and its chip, which can generate various linear frequency modulation patterns and can also realize amplitude modulation and phase modulation functions.

[0007] This utility model is achieved through the following technical solution:

[0008] An ultrasonic sensor, based on a crystal oscillator clock generator and a direct digital frequency synthesizer, is used in conjunction with a transducer and includes an ultrasonic signal generation and transmission module and an ultrasonic signal receiving and quantization module.

[0009] The ultrasonic signal generation and transmission module includes a crystal oscillator, a direct digital frequency synthesizer, a programmable pulse generator, and an amplifier connected in sequence; the crystal oscillator is also connected to a frequency multiplier / divider; the frequency multiplier / divider is connected to the ultrasonic signal receiving and quantization module.

[0010] The amplifier is a two-channel analog amplifier, which is connected to the transmit channel TX0 and the transmit channel TX1 respectively.

[0011] A chip, said chip being made from the aforementioned ultrasonic sensor.

[0012] Compared with previous technologies, the beneficial effects of this utility model are as follows:

[0013] 1. This utility model can generate various linear frequency modulation patterns (such as triangular waves, sawtooth waves, etc.), and can also realize amplitude modulation and phase modulation functions. At the same time, the introduced signal jitter is minimal, thus significantly reducing the difficulty of signal processing at the receiving end. By optimizing signal characteristics, it can improve detection accuracy and anti-interference capability.

[0014] 2. Compared with traditional PLL-based clock generators, the clock generation circuit of this invention can significantly reduce clock jitter, improve clock quality, and significantly reduce the complexity of clock generation and chip power consumption.

[0015] 2. The clock signal generated by the crystal oscillator is multiplied / divided by the frequency multiplier module to provide a high-quality sampling clock for the ADC and digital module in the receiving path, which helps to improve the effective bits and signal-to-noise ratio of the ADC. Attached Figure Description

[0016] Figure 1 This is a block diagram of the modules of this utility model;

[0017] Figure 2 The simulation waveform diagram is shown for the direct digital frequency synthesizer that integrates frequency modulation, amplitude modulation, and phase modulation functions according to this utility model. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description:

[0019] like Figure 1 As shown, an ultrasonic sensor is used in conjunction with a transducer, characterized in that it includes an ultrasonic signal generation and transmission module and an ultrasonic signal receiving and quantization module.

[0020] The ultrasonic signal generation and transmission module includes a crystal oscillator, a direct digital frequency synthesizer, a programmable pulse generator, and an amplifier connected in sequence; the crystal oscillator is also connected to a frequency multiplier / divider; the frequency multiplier / divider is connected to the ultrasonic signal receiving and quantization module.

[0021] The amplifier is a two-channel analog amplifier, which is connected to the transmit channel TX0 and the transmit channel TX1 respectively.

[0022] The crystal oscillator is connected to a passive crystal forming clock generation circuit. Compared with traditional PLL-based clock generators, the chip manufactured by this invention can significantly reduce clock jitter, improve clock quality, and significantly reduce the complexity of clock generation and chip power consumption.

[0023] Meanwhile, the clock signal generated by the crystal oscillator is fed into the ADC and digital module of the receiving path by the frequency multiplier / divider module, which provides a high-quality sampling clock and helps to improve the effective bits and signal-to-noise ratio of the ADC.

[0024] This invention optimizes the circuit structure from a system configuration perspective. It employs a fast-start crystal oscillator clock (clock generation circuit) as the clock signal source for the sensor system, significantly shortening the clock settling time and achieving better jitter performance than traditional phase-locked loop (PLL) based clocks. A direct digital frequency synthesizer is used, enabling simultaneous frequency modulation, amplitude modulation, and phase modulation, providing greater optimization space for signal processing at the receiving end and contributing to improved sensor detection accuracy and anti-interference capabilities. The programmable pulse generator processes the linearly frequency-modulated clock signal, primarily enabling programmable configuration of the pulse width and the number of pulses per cycle. The final stage of the transmitting channel is an amplifier, specifically two analog amplifiers, used to generate pulse signals capable of driving two transducers.

[0025] Furthermore, the ultrasonic signal receiving and quantization module includes a selector, a programmable amplifier, an analog-to-digital converter, a digital filter, and a data buffer connected in sequence.

[0026] The selector is connected to a first receiving terminal RX0 and a second receiving terminal RX1; the frequency multiplier / divider is connected to the analog-to-digital converter and the digital filter, respectively.

[0027] The main function of the analog selector is to select which transducer receives the signal and send that signal to the programmable amplifier for amplification. The amplified signal is then quantized into a digital signal by the analog-to-digital converter, and after passing through a digital filter, it is stored in a data buffer for subsequent digital signal processing.

[0028] This invention also provides a chip, which is fabricated from the ultrasonic sensor. The ultrasonic sensor of this invention can generate various linear frequency modulation patterns (such as triangular waves, sawtooth waves, etc.), and can also achieve amplitude modulation and phase modulation functions. Simultaneously, it introduces minimal signal jitter, thus significantly reducing the difficulty of signal processing at the receiving end, and improving detection accuracy and anti-interference capability by optimizing signal characteristics. Figure 2 As shown, Figure 2 This is a simulation waveform diagram of a direct digital frequency synthesizer that integrates frequency modulation, amplitude modulation, and phase modulation functions. It can generate full-scale sine waves, frequency-modulated and amplitude-modulated sine waves, and can also reduce the amplitude to zero at any time when power is turned off.

[0029] Although this utility model has been illustrated and described using specific embodiments and alternative methods, it should be understood that various changes and modifications are permitted as long as they do not depart from the spirit and scope of this utility model. Therefore, it should be understood that this utility model is not limited in any sense except by the appended claims and their equivalents.

Claims

1. An ultrasonic sensor for use with a transducer, characterized in that, It includes an ultrasonic signal generation and transmission module and an ultrasonic signal receiving and quantization module; The ultrasonic signal generation and transmission module includes a crystal oscillator, a direct digital frequency synthesizer, a programmable pulse generator, and an amplifier connected in sequence; the crystal oscillator is also connected to a frequency multiplier / divider; the frequency multiplier / divider is connected to the ultrasonic signal receiving and quantization module. The amplifier is a two-channel analog amplifier, which is connected to the transmit channel TX0 and the transmit channel TX1 respectively.

2. An ultrasonic sensor according to claim 1, characterized in that, The ultrasonic signal receiving and quantization module includes a selector, a programmable amplifier, an analog-to-digital converter, a digital filter, and a data buffer connected in sequence. The selector is connected to a first receiver RX0 and a second receiver RX1; the frequency multiplier / divider is connected to an analog-to-digital converter and a digital filter, respectively.

3. An ultrasonic sensor according to claim 1, characterized in that: The crystal oscillator is connected to a passive crystal forming clock generation circuit.

4. A chip, characterized in that: The chip is made from the ultrasonic sensor described in any one of claims 1-3.

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