An output programmable airflow detection chip

Abstract

The application discloses an output programmable airflow detection chip, which comprises an airflow detection module (101), a signal processing module (102), a programmable modulation module (103), a driving module (104) and a sampling module (105). The airflow detection module (101) detects the input airflow and outputs to the signal processing module (102). The sampling module (105) samples the output of the driving module (104) and outputs to the signal processing module (102). The signal processing module (102) obtains a digital signal representing the difference between the two through logical operation. The programmable modulation module (103) modulates the digital signal, finally adjusts the duty cycle of the output signal of the driving module (104), realizes airflow detection output in different modes, such as average value mode analog output, root mean square mode analog output, constant average value and constant root mean square, etc. The airflow detection chip has the characteristics of high airflow detection precision, high integration, wide application range, etc. and can be used for electronic cigarettes.

Description

Technical Field

[0001] This invention mainly relates to the field of airflow sensing technology, and more specifically, to a programmable airflow detection chip that can be applied to electronic cigarette driver chips. Background Technology

[0002] Traditional airflow detection solutions often employ a discrete approach consisting of an airflow sensor module, an MCU (microcontroller), and power transistors, such as... Figure 1 As shown, the MCU detects and controls the power transistor's on / off state based on the airflow sensor module's output. Simultaneously, the MCU's AD quantization channel samples the power transistor's output signal in real time, adjusting the power transistor's on / off time to regulate the average amplitude or root mean square (RMS) of the output signal. Since the airflow sensor module can only output digital signals "0" or "1," the MCU directly controls the power transistor's on-time based on this digital signal. This results in the circuit only outputting a single voltage or current signal, leading to a single, unadjustable driving capability that cannot meet the wide-range power output requirements of different markets. Some airflow sensor drive solutions use MCUs with built-in OTP (One-Time Programmable) for simple output adjustment, but the output power levels are limited, and the output power range is narrow, making it difficult to meet the needs of different consumer groups or other application areas. Furthermore, this solution requires an MCU, power transistor, and airflow sensor detection module, resulting in low integration, high failure rate, and increased design costs. Therefore, designing an airflow detection chip with multi-mode, wide-range output characteristics for both input airflow and output electrical signals is a pressing problem that needs to be solved in the ongoing development of the airflow sensor drive field.

[0003] Therefore, it is necessary to provide a programmable airflow detection technology to overcome the above-mentioned shortcomings.

[0004] To solve the above-mentioned technical problems, the present invention proposes a programmable airflow detection chip, which mainly includes an airflow detection module (101), a signal processing module (102), a programmable modulation module (103), a driving module (104), and a sampling module (105). The airflow detection module (101) detects the input airflow and outputs it to the signal processing module (102) to realize the conversion of airflow into an electrical signal, such as a clock signal. The signal processing module (102) performs calculations on the electrical signal to obtain a digital signal representing the input airflow in the target mode. The sampling module (105) samples the output of the driving module (104) and outputs it to the signal processing module (102). The signal processing module (102) performs logical operations on the digital signal representing the flow rate input under the target mode and the sample representing the current output signal to obtain a digital signal representing the difference between the target output value and the actual output value. The programmable modulation module (103) modulates the digital signal and adjusts the duty cycle of the output signal of the drive module (104) to realize different modes of airflow detection output, such as average value mode analog output, root mean square mode analog output, constant average value and constant root mean square mode, thereby solving the problem of limited output power levels and narrow power range. The airflow detection chip proposed in this patent has the characteristics of high airflow detection accuracy, high integration and wide applicability, and can be used in electronic cigarettes. Summary of the Invention

[0005] The main problem to be solved by this invention is: In view of the problems existing in the prior art, this invention provides a programmable airflow detection chip. This chip senses the external input airflow through a pressure-sensitive device, obtains the capacitance change caused by the airflow, and uses capacitor charging and discharging technology to convert the airflow change into frequency change, thereby realizing the conversion of airflow into electrical signal. The signal processing module (102) uses timing technology to perform logical operation processing on the electrical signal generated by the airflow sensor to obtain a digital signal representing the input airflow in the target mode. At the same time, the signal processing module (103) performs logical operation on the signal and the output signal of the sampling module (105) to obtain a digital signal of the difference between the target output value and the actual output value. After the programmable modulation module (103) modulates the signal, it is output to the input terminal of the driving module (104), such as pulse swallowing or pulse adding modulation technology. The driving module (104) adjusts the duty cycle of the output of the output driving tube according to the input digital signal, and then outputs a signal that can represent the corresponding airflow in the target mode. Since the signal change in the entire signal path of this invention maintains a corresponding proportional relationship with the input airflow in real time, it exhibits good output response characteristics and can better meet the actual needs of different application fields.

[0006] To solve the above technical problems, the solution proposed by the present invention is: an output programmable airflow detection chip, including an airflow detection module (101), a signal processing module (102), a programmable modulation module (103), a driving module (104), and a sampling module (105).

[0007] The airflow detection module (101) is mainly used to detect the input airflow and realize the conversion of airflow into electrical signals. Its output is connected to the first input terminal of the signal processing module (102). The second input terminal of the signal processing module (102) is connected to the output terminal of the sampling module (105). The output of the signal processing module (102) is connected to the input terminal of the programmable modulation module (103). The output of the programmable modulation module (103) is connected to the input terminal of the driving module (104). The output of the driving module (104) is connected to the input terminal of the sampling module (105).

[0008] The signal processing module (102), programmable modulation module (103), drive module (104), and sampling module (105) form a closed-loop control system, which adjusts the duty cycle of the signal output by the drive module (104) in real time to ensure that the output of the drive module (104) establishes a corresponding proportional relationship with the input air flow rate, and realizes the average value mode analog output, root mean square mode analog output, constant average value and constant root mean square mode, etc. The analog output characteristics include, but are not limited to, a fixed direct proportional relationship in which the larger the air flow input, the larger the output signal amplitude, a fixed inverse proportional relationship in which the larger the air flow input, the smaller the output signal amplitude, and a proportional relationship in which any input air flow corresponds to a certain fixed output signal amplitude, such as constant average value and constant root mean square mode, etc.

[0009] The signal processing module (102) of the airflow detection chip described above mainly performs quantization processing on the output signal of the airflow detection module (101) according to the corresponding mode. For the analog output of the average value mode, the output mode with a fixed proportional relationship obtains a digital signal multiplied by a fixed proportional coefficient and the input airflow rate. The average value output mode with a fixed inverse proportional relationship obtains a digital signal multiplied by a fixed inverse proportional coefficient and the input airflow rate. The constant average value mode obtains a fixed digital signal corresponding to the average value. The quantization processing method is similar for the analog output of the root mean square mode and the constant mean square mode. The signal processing module (102) performs logical operation processing on the digital signal obtained by the above quantization processing and the signal output by the sampling module (105) to obtain a digital signal representing the difference between the target output value and the actual output value, and outputs it to the input terminal of the programmable modulation module (103). The programmable modulation module (103) adjusts the output duty cycle of the driving module (104) through the corresponding modulation method based on the input digital signal and the current output mode, and finally obtains the output of the target mode.

[0010] The aforementioned airflow detection chip, specifically the programmable modulation module (103), primarily adjusts the output duty cycle based on a digital signal representing the difference between the target output value and the actual value, combined with the output mode. The main modulation methods include, but are not limited to, pulse swallowing technology and pulse compensation technology.

[0011] The aforementioned airflow detection chip has high integration and wide-range, multi-mode output characteristics. At the same time, it isolates the external environment from direct contact with the airflow detection module, greatly improving the chip's anti-interference capability.

[0012] Compared with the prior art, the advantages of the present invention are as follows:

[0013] 1. It features multi-mode, wide-range output characteristics. Compared with traditional airflow sensing and driving technology, this invention uses charge-discharge technology to sense the capacitance changes caused by airflow, obtaining frequency characteristics that characterize the input airflow. Through logical processing, it obtains a digital signal corresponding to the input airflow in the target mode, ultimately controlling the drive module to generate the duty cycle of the corresponding output signal. This achieves a target correspondence between the input airflow and the output signal, such as a fixed direct proportional relationship (average or root mean square analog output mode), a fixed inverse proportional relationship (average or root mean square analog output mode), a constant average value output mode, and a constant root mean square output mode. Therefore, it exhibits excellent airflow detection response characteristics.

[0014] 2. It has extremely strong anti-interference capabilities; compared with traditional airflow sensing and driving technology, this invention integrates the airflow detection module into the chip, isolating the external environment from direct contact with the airflow detection module, thus improving the chip's ability to prevent liquid leakage.

[0015] 3. Excellent integration characteristics. Compared with traditional airflow sensing drive technology, this invention integrates the airflow detection module, external drive MOS, and output detection logic into a single chip, reducing the application development component BOM, lowering the failure rate, and exhibiting excellent integration characteristics. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a traditional airflow sensor driver chip.

[0017] Figure 2 This is the single-average output waveform of a traditional airflow detection chip.

[0018] Figure 3 This is a single root mean square output waveform diagram of a traditional airflow detection chip.

[0019] Figure 4 This is a schematic diagram of the airflow detection chip structure of the present invention;

[0020] Figure 5This is a waveform diagram of the fixed proportional analog output of the airflow detection chip of the present invention in root mean square mode.

[0021] Figure 6 This is a waveform diagram of the fixed proportional analog output of the airflow detection chip in the average value mode of the present invention;

[0022] Figure 7 This is a waveform diagram of the fixed inverse ratio analog output of the airflow detection chip in root mean square mode of the present invention;

[0023] Figure 8 This is a waveform diagram of the fixed inverse analog output of the airflow detection chip in the average value mode of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Please see Figure 4 As shown, the present invention provides a programmable airflow detection chip, which mainly includes an airflow detection module (101), a signal processing module (102), a programmable modulation module (103), a driving module (104), and a sampling module (105).

[0026] The airflow detection module (101) is mainly used to detect the input airflow and realize the conversion of airflow into electrical signal. Its output is connected to the first input terminal of the signal processing module (102). The second input terminal of the signal processing module (102) is connected to the output terminal of the sampling module (105). The output of the signal processing module (102) is connected to the input terminal of the programmable modulation module (103). The output of the programmable modulation module (103) is connected to the input terminal of the drive module (104). The output of the drive module (104) is connected to the input terminal of the sampling module (105).

[0027] Combination Figure 4 As shown, the driver chip mainly includes an airflow detection module (101), a signal processing module (102), a programmable modulation module (103), a driver module (104), and a sampling module (105). The specific implementation is as follows:

[0028] When airflow is input into the airflow detection module (101), the pressure-sensitive device inside the detection module will undergo structural deformation due to the pressure change caused by the airflow input. For example, the distance between the two plates of the capacitive pressure-sensitive device will deform due to the pressure, resulting in a change in capacitance. For the change in capacitance, the frequency change before and after the pressure change can be obtained by using an oscillator with charge and discharge technology, thereby realizing the conversion of airflow into electrical signal.

[0029] The frequency-representing electrical signal output by the airflow detection module (101) is directly input to the signal processing module (102). This module uses appropriate sampling techniques to convert the signal into a digital signal characterizing frequency changes. Specifically, this can be achieved, but is not limited to, counting the signal before and after frequency changes using timing techniques, thus converting the airflow into a quantifiable digital signal. After obtaining the digital signal that characterizes the input airflow, the signal processing module will perform the following signal processing for different output modes:

[0030] 1) The analog output of the fixed proportional relationship average value mode multiplies the fixed proportional coefficient with the digital signal representing the input air flow rate to obtain the digital signal corresponding to the target average value; at the same time, the sampling module (105) samples the drive module (104) to obtain the real-time output signal; the signal processing module subtracts the above two digital signals to obtain the digital signal representing the difference between them and inputs it to the programmable modulation module (103). The programmable modulation module (103) uses pulse addition and subtraction technology to modulate the difference signal and outputs it to the input terminal of the drive module (104) to realize the duty cycle adjustment of the output signal, so as to achieve a one-to-one proportional relationship between the input air flow rate and the average value of the output signal, such as Figure 6 As shown.

[0031] 2) The analog output of the fixed inverse proportional relationship average value mode multiplies the fixed inverse proportional coefficient with the digital signal representing the input air flow rate to obtain the digital signal corresponding to the target average value; at the same time, the sampling module (105) samples the drive module (104) to obtain the real-time output signal; the signal processing module subtracts the above two digital signals to obtain the digital signal representing the difference between them and inputs it to the programmable modulation module (103). The programmable modulation module (103) uses pulse addition and subtraction technology to modulate the difference signal and outputs it to the input terminal of the drive module (104) to realize the duty cycle adjustment of the output signal, so as to achieve the inverse proportional relationship of one-to-one mapping between the input air flow rate and the average value of the output signal, such as Figure 8 As shown.

[0032] 3) The analog output of the root mean square mode with a fixed proportional relationship is processed by multiplying the fixed proportional coefficient with the digital signal representing the input air flow rate to obtain the digital signal corresponding to the target root mean square; at the same time, the sampling module (105) samples the drive module (104) to obtain the real-time output signal; the signal processing module performs a subtraction operation on the above two digital signals to obtain a digital signal representing the difference between the two and inputs it to the programmable modulation module (103). The programmable modulation module (103) uses pulse addition and subtraction technology to modulate the difference signal and outputs it to the input terminal of the drive module (104) to realize the duty cycle adjustment of the output signal, so as to achieve a one-to-one proportional relationship between the input air flow rate and the root mean square of the output signal, such as Figure 5 As shown.

[0033] 4) The analog output of the root mean square mode with a fixed inverse proportional relationship is processed by multiplying the fixed inverse proportional coefficient with the digital signal representing the input air flow rate to obtain the digital signal corresponding to the target root mean square; at the same time, the sampling module (105) samples the drive module (104) to obtain the real-time output signal; the signal processing module subtracts the above two digital signals to obtain the digital signal representing the difference between them and inputs it to the programmable modulation module (103). The programmable modulation module (103) uses pulse addition and subtraction technology to modulate the difference signal and outputs it to the input terminal of the drive module (104) to realize the duty cycle adjustment of the output signal, so as to achieve an inverse proportional relationship between the input air flow rate and the root mean square of the output signal, such as Figure 7 As shown.

[0034] 5) Constant average value mode output: When the signal processing module (102) detects that the input air flow rate reaches the output threshold, the signal processing module (102) will obtain the digital signal representing the target average value through a lookup table, and at the same time, the sampling module (105) will sample the drive module (104) to obtain the real-time output signal; the signal processing module will subtract the above two digital signals to obtain the digital signal representing the difference between them and input it to the programmable modulation module (103). The programmable modulation module (103) will use pulse addition and subtraction technology to modulate the difference signal and output it to the input terminal of the drive module (104) to realize the duty cycle adjustment of the output signal, so that a fixed average value is output when any input air flow rate greater than the output threshold is input. Figure 2 As shown.

[0035] 6) Constant root mean square (RMS) mode output: When the signal processing module (102) detects that the input airflow rate reaches the output threshold, the signal processing module (102) will obtain the digital signal representing the target RMS value through a lookup table, and at the same time, the sampling module (105) will sample the drive module (104) to obtain the real-time output signal; the signal processing module will subtract the above two digital signals to obtain a digital signal representing the difference between them and input it to the programmable modulation module (103). The programmable modulation module (103) will use pulse addition and subtraction technology to modulate the difference signal and output it to the input terminal of the drive module (104) to realize the duty cycle adjustment of the output signal, so that a fixed RMS value is output when any input airflow rate is greater than the output threshold, such as Figure 3 As shown.

[0036] When the entire airflow detection chip experiences abnormal phenomena such as low power supply, high operating temperature, high output current, or open / short circuit of the load, the sampling module (105) can promptly acquire abnormal information and output it to the signal processing module (102), and process it in a timely manner through the programmable modulation module (103). The module generates a corresponding control signal to promptly shut down the drive module (104) to achieve the purpose of protecting the drive chip.

[0037] The schematic diagrams and implementations of the above modules refer to all implementation schemes with this function. The circuits shown in the above figures are merely examples; changes in the circuit caused by simply replacing the components also fall within the scope of protection of this invention. The scope of protection of this invention should be determined by the claims.

Claims

1. A programmable airflow detection chip, characterized in that: It includes an airflow detection module (101), a signal processing module (102), a programmable modulation module (103), a driving module (104), and a sampling module (105). The airflow detection module (101) is mainly used to detect the input airflow and obtain the frequency change before and after the air pressure change to realize the conversion of airflow into electrical signal. Its output is connected to the first input terminal of the signal processing module (102). The second input terminal of the signal processing module (102) is connected to the output terminal of the sampling module (105). The output of the signal processing module (102) is connected to the input terminal of the programmable modulation module (103). The output of the programmable modulation module (103) is connected to the input terminal of the driving module (104). The output of the driving module (104) is connected to the input terminal of the sampling module (105). The signal processing module (102) is used to perform corresponding mode quantization processing on the frequency-represented signal output by the airflow detection module (101); The sampling module (105) is used to sample the drive module (104) to obtain the real-time output signal; The signal processing module (102) performs logical operations on the digital signal obtained by the above quantization process and the signal output by the sampling module (105) to obtain a digital signal representing the difference between the target output value and the actual output value, and outputs it to the input terminal of the programmable modulation module (103). Based on the input digital signal and the current output mode, the programmable modulation module (103) adjusts the output duty cycle of the drive module (104) through the corresponding modulation method to finally obtain the output of the target mode; The signal processing module (102), programmable modulation module (103), drive module (104), and sampling module (105) form a closed-loop control system, which adjusts the duty cycle of the signal output by the drive module (104) in real time to ensure that the output of the drive module (104) establishes a corresponding proportional relationship with the input air flow rate, realizing the analog output in average mode, the analog output in root mean square mode, the constant average mode, and the constant root mean square mode. The analog output characteristics include, but are not limited to, a fixed direct proportional relationship in which the larger the air flow input, the larger the output signal amplitude, a fixed inverse proportional relationship in which the larger the air flow input, the smaller the output signal amplitude, and a proportional relationship in which any input air flow corresponds to a certain fixed output signal amplitude.

2. The airflow detection chip as described in claim 1, characterized in that: For analog output in average value mode, the output mode with a fixed direct proportionality yields a digital signal resulting from the product of a fixed direct proportionality coefficient and the input air flow rate; the average value output mode with a fixed inverse proportionality yields a digital signal resulting from the product of a fixed inverse proportionality coefficient and the input air flow rate; the constant average value mode yields a fixed digital signal corresponding to the average value; the quantization process is similar for analog output in root mean square mode and constant mean square mode.

3. The airflow detection chip as described in claim 1, characterized in that: The programmable modulation module (103) is mainly based on the digital signal representing the difference between the target output value and the actual value, and adjusts the output duty cycle in combination with the output mode. The main modulation methods include, but are not limited to, pulse swallowing technology and pulse compensation technology.

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