AD sampling device, AD sampling method and electrical appliance

Abstract

The present invention discloses an AD sampling device, an AD sampling method, and an electrical appliance. The AD sampling device includes an AD sampling unit for collecting a signal to be sampled, a power supply unit for supplying power to the AD sampling unit, and a signal generating unit connected to the AD sampling unit. The signal generating unit is configured to output a reference signal to the AD sampling unit, and the AD sampling unit compares the signal to be sampled with the reference signal to obtain an AD value. Compared to the prior art, the present invention provides an AD sampling device and an AD sampling method that improve the resolution of AD sampling without requiring additional external devices and circuits, meeting the requirements for collecting higher-precision analog signals.

Description

Technical Field

[0001] The present invention relates to the field of AD sampling technology, in particular to an AD sampling device, an AD sampling method and an electrical appliance. Background Art

[0002] The AD sampling resolution of traditional embedded processors is determined solely by the chip's design. For example, a 10-bit AD sampling rate can only capture 1024 AD values, which is sufficient for general analog signal acquisition and cannot be used for signals requiring higher resolution. For example, a 10-bit AD sampling rate for a temperature sensor can only capture 0.1°C resolution, and cannot achieve 0.05°C resolution. The conventional method for improving AD sampling is to install a high-precision external ADC sampling chip and transmit it to the main chip via communication. This occupies the main chip's already limited SPI or IIC interfaces, occupies a large circuit area, and is costly.

[0003] Therefore, how to design an AD sampling device, AD sampling method and electrical appliance that can improve AD sampling resolution is a technical problem that needs to be solved urgently in the industry. Summary of the Invention

[0004] Aiming at the problem in the prior art that the AD sampling resolution can only be determined according to the chip design itself and the AD sampling resolution cannot be improved, the present invention proposes an AD sampling device, an AD sampling method and an electrical appliance.

[0005] The technical solution of the present invention is to propose an AD sampling device, which includes: an AD sampling unit for collecting a signal to be sampled, and a power supply unit for supplying power to the AD sampling unit; and also includes a signal generating unit connected to the AD sampling unit, the signal generating unit being used to output a reference signal to the AD sampling unit, and the AD sampling unit comparing the signal to be sampled with the reference signal to obtain an AD value.

[0006] Furthermore, the signal generating unit is connected to the power supply unit and is used to extract the ripple in the power supply unit and output it as the reference signal to the AD sampling unit.

[0007] Furthermore, the amplitude of the ripple satisfies: V 纹波 ≥(V 电源 *j) / 2 p ;

[0008] Among them, V 纹波 is the ripple voltage, V 电源 is the output voltage of the power supply unit, p is the fixed sampling bit number of the AD sampling unit, and j is a constant greater than 3.

[0009] Furthermore, the AD value of the sampled signal is: M= (Vref / V0)*2 p ;

[0010] Wherein, M is the AD value sampled by the AD sampling device, Vref is the voltage value of the reference signal, V0 is the voltage value of the signal to be sampled, and p is the fixed sampling bit number of the AD sampling unit.

[0011] Furthermore, when the sampling bit number of the AD sampling device is increased by i bits, the AD sampling unit collects multiple samples of the signal to be sampled, and the AD value of the signal to be sampled is: M0=(M1+M2+M3+...+M N ) / (N / 2 i );

[0012] Wherein, M0 is the AD value of the signal to be sampled when the number of sampling bits of the AD sampling device is increased by i bits, M N is the AD value of the Nth sampling, and i is the number of bits increased by the AD sampling device compared with the fixed sampling bit number of the AD sampling unit.

[0013] The present invention also proposes an AD sampling method, which includes:

[0014] Output reference signal to AD sampling unit;

[0015] The AD sampling unit collects the signal to be sampled and the reference signal;

[0016] The signal to be sampled is compared with the reference signal to obtain an AD value of the signal to be sampled.

[0017] Furthermore, it also includes:

[0018] Sampling multiple times and obtaining the AD value of the signal to be sampled;

[0019] The AD value of the signal to be sampled after the number of bits to be increased is calculated according to the number of bits that the AD sampling device needs to increase and the AD value of the signal to be sampled after multiple samplings.

[0020] Furthermore, the sampling times of the signal to be sampled is: N=k*2i, where N is the sampling times, k is a constant greater than 3, and i is the number of bits increased by the AD sampling device compared to the fixed sampling bit number of the AD sampling unit.

[0021] Furthermore, before sampling multiple times and obtaining the AD value of the signal to be sampled, it is necessary to determine the type of the reference signal. When the reference signal is a fluctuating signal, the total time of multiple sampling of the signal to be sampled is set to be equal to the period of the reference signal.

[0022] Furthermore, when the total time of the AD sampling is not equal to the period of the reference signal, the operating frequency of the power supply unit is adjusted until the total time of multiple samplings of the signal to be sampled is equal to the period of the reference signal.

[0023] The present invention further provides an electrical appliance, which comprises the above-mentioned AD sampling device and performs AD sampling on an analog signal of the electrical appliance through the AD sampling device.

[0024] Furthermore, the electrical appliance is an air conditioner or a refrigerator, and the analog signal sampled by the AD sampling device is temperature.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The present invention proposes an AD sampling device and an AD sampling method, which do not require any other external devices and circuits, can directly provide a reference signal to the AD sampling unit through its own power supply unit, and perform AD sampling based on the reference signal. At the same time, the present invention can also perform multiple sampling through the AD sampling unit to improve the resolution of AD sampling and meet the sampling requirements of higher sampling accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 Schematic diagram of the hardware connection of the AD sampling device of the present invention. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Thus, a feature indicated in this specification is intended to illustrate one of the features of one embodiment of the present invention, rather than to imply that every embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other, not explicitly described, combinations. Thus, unless otherwise noted, the described combinations are not intended to be limiting.

[0031] The principle and structure of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0032] The resolution of traditional AD sampling devices is determined solely by their design, making them incapable of high-precision AD sampling. This often requires an external high-precision ADC sampling chip, which increases the cost of AD sampling. The present invention proposes an AD sampling device and method that extracts ripple from its own power supply unit through a signal generating unit and transmits it as a reference signal to the AD sampling unit for AD sampling of the signal to be sampled. Furthermore, multiple sampling by the AD sampling unit can achieve high-precision sampling, meeting even higher-precision sampling requirements.

[0033] See Figure 1 The AD sampling device proposed in the present invention comprises:

[0034] An AD sampling unit having an AD port for receiving a signal to be sampled and a Vref port for receiving a reference signal, which can be used to compare the voltage of the signal to be sampled with the reference signal to obtain an AD value of the signal to be sampled. In the present invention, the AD sampling unit adopts an embedded IC;

[0035] A power supply unit, which serves as a power source of the AD sampling device and is used to supply power to the AD sampling unit to maintain its sampling operation. In the present invention, the power supply unit adopts a conventional VCC power supply;

[0036] The signal generating unit is connected to the power supply unit and the AD sampling unit respectively, and can be used to extract the ripple generated by the power supply unit and give it to the AD sampling unit. The ripple is connected to the Vref port of the AD sampling unit and used as the reference signal of the AD sampling unit. In the present invention, the signal generating unit adopts a noise generating device.

[0037] Furthermore, the AD sampling unit is used to compare the voltage value of the reference signal with the voltage value of the signal to be sampled to obtain the AD value of the signal to be sampled. The number of bits of AD sampling of the AD sampling unit is generally 10 bits or 12 bits. The sampling number of the embedded IC used in the AD sampling unit of the present invention is 10 bits. The AD sampling unit makes the AD value corresponding to the reference signal 2 10 , and then compare the voltage value of the signal to be sampled with the voltage value of the reference signal to obtain the AD value of the signal to be sampled. The AD value of the signal to be sampled is: M=(Vref / V0)*2 p ;

[0038] Where M is the AD value of the signal to be sampled, Vref is the voltage value of the reference signal, V0 is the voltage value of the signal to be sampled, and p is the fixed number of sampling bits of the AD sampling unit. Since the ratio of the voltage value of the reference signal to the voltage value of the signal to be sampled corresponds to the ratio of the AD value of the reference signal to the AD value of the signal to be sampled, the present invention can obtain the AD value of the signal to be sampled using the above formula.

[0039] For example, if the voltage value of the reference signal is 5V and the voltage value of the signal to be sampled is 2.5V, the fixed sampling bit of the AD sampling device in the present invention is 10 bits, and the AD sampling device makes the AD value corresponding to the reference signal 2 10 , the ratio of the voltage value of the reference signal to the voltage value of the signal to be sampled is (5 / 2.5) = 2, and the ratio of the corresponding AD values ​​is also 2, so it can be concluded that the AD value of the signal to be sampled is 2 10 / 2=2 9 =512.

[0040] The present invention can be used to increase the number of AD sampling bits, that is, to increase the resolution of AD sampling. The solution is to perform multiple sampling on the signal to be sampled based on the fixed number of sampling bits of the AD sampling unit, and then obtain the AD value of the signal to be sampled after the number of sampling bits is increased according to the results of the multiple sampling of the signal to be sampled and the number of sampling bits to be increased. The AD value of the signal to be sampled after the number of sampling bits is increased is: M0=(M1+M2+M3+...+M N ) / (N / 2 i ); wherein M0 is the AD value of the signal to be sampled after the number of bits is increased, M1 is the AD value of the first sampling of the AD sampling unit based on the fixed sampling number, M2 is the AD value of the second sampling of the AD sampling unit based on the fixed sampling number, M3 is the AD value of the third sampling of the AD sampling unit based on the fixed sampling number, M N is the AD value sampled by the AD sampling unit based on the fixed sampling bit number, N is the number of times the signal to be sampled is sampled, and i is the number of bits increased by the AD sampling device compared to the fixed sampling bit number of the AD sampling unit.

[0041] The sampling principle is similar to that of single sampling. Here, the increased bit number i is set to 2, and the fixed sampling bit number of the AD sampling unit is 10. In this case, the AD value corresponding to the voltage value of the reference signal becomes 2 12 Since the sampling bit number of the AD sampling unit itself cannot be increased, it still samples the signal to be sampled based on the fixed sampling bit number 10. The AD value obtained is still the AD value under the fixed sampling bit number 10, and the corresponding relationship between the voltage value of the reference signal and the AD value becomes Vref: 2 12 , that is (Vref / 2 2 ):2 10In this case, the corresponding relationship between the voltage value of the signal to be sampled and its AD value should also be: (V0 / 2 2 ): Mn, where Mn is the AD value of the signal to be sampled at the nth sampling (based on a fixed sampling bit number of 10 bits), and V0 is the voltage value of the signal to be sampled. Since the voltage value of the reference signal in the current case matches the AD value after the number of bits is increased, the AD value corresponding to the voltage value of the current signal to be sampled is also the AD value after the number of bits is increased. By transforming the above formula, the corresponding relationship between the voltage value and AD value of the signal to be sampled is: V0: Mn / (1 / 2 2 ), the present invention performs multiple sampling, and uses its average as the AD value after increasing the number of bits to improve the accuracy of AD sampling. Therefore, the AD value obtained after the number of bits of the sampled signal is increased is M0=(M1+M2+M3+...+M N ) / (N / 2 i ).

[0042] In order to achieve better sampling effect and obtain more accurate AD value, the sampling times of the signal to be sampled are set as follows: N=k*2i, where N is the sampling times, k is a constant greater than 3, and i is the number of bits increased by the AD sampling device compared with the fixed sampling bit number of the AD sampling unit.

[0043] The present invention also proposes an AD sampling method, which includes:

[0044] Output reference signal to AD sampling unit;

[0045] The AD sampling unit collects the signal to be sampled and the reference signal;

[0046] The AD value of the signal to be sampled is obtained by comparing the signal to be sampled with the reference signal.

[0047] In order to obtain the AD value after the number of bits is increased, the sampling method of the present invention further includes:

[0048] Sampling multiple times and obtaining the AD value of the signal to be sampled;

[0049] The AD value of the signal to be sampled after the number of bits to be increased is calculated according to the number of bits that the AD sampling device needs to increase and the AD value of the signal to be sampled after multiple samplings.

[0050] The present invention performs multiple sampling of the signal to be sampled. For a periodic fluctuating signal, if the AD value corresponding to the voltage value within its full period can be sampled, its voltage conversion can be more accurately reflected. Therefore, the present invention makes the total time used for multiple AD sampling equal to the AD sampling period, so that the AD value of the signal to be sampled within the full period can be collected to obtain a better sampling effect.

[0051] When the power supply unit uses a switching power supply circuit, its ripple is a periodic, fluctuating signal. When the power supply unit is a linear regulator or LDO, its ripple is a linear signal. Linear signals generally do not have periodic properties. Therefore, before considering the total sampling time of the signal to be sampled, it is necessary to determine the reference signal, that is, the type of ripple. Only when the reference signal is a periodic, fluctuating signal will the total time of multiple AD sampling equal its period. If the ripple is a linear signal, since it inherently changes linearly, the impact of voltage fluctuations within its period does not need to be considered, meaning there is no need to set a specific sampling time.

[0052] In the present invention, to obtain more accurate AD sampling values, the number of sampling times is set to N = k * 2i. However, due to the sampling time interval of the AD sampling unit or the period of the ripple, it may be impossible to meet the requirement that the total time of N AD sampling times equals the reference signal period. In this case, it is necessary to increase the period of the reference signal, that is, the period of the ripple. In the present invention, the operating frequency of the power supply unit is adjusted to increase the period of the reference signal until it meets the requirement that the total time of N AD sampling times equals the reference signal period. The relationship between frequency and period is: T = 1 / f. Therefore, in the present invention, the period requirement can be met by reducing the operating frequency of the power supply unit.

[0053] Furthermore, since the ripple is extracted from the output signal of the power supply, in order to extract the ripple, the ripple value needs to meet the following requirements: V 纹波 ≥(V 电源 *j) / 2 p ; Among them, V 纹波 is the ripple voltage (value), V 电源 is the output voltage of the power supply unit, p is the fixed sampling bit number of the AD sampling unit, and j is a constant greater than 3.

[0054] The present invention also provides an electrical appliance, which has the above-mentioned AD sampling device and performs AD sampling on an analog signal of the electrical appliance through the AD sampling device.

[0055] Furthermore, the aforementioned electrical appliance is an air conditioner or a refrigerator, and the analog signal sampled by the AD sampling device is temperature. It should be noted that the present invention is applicable not only to air conditioners or refrigerators, but is also applicable to other electrical appliances that require analog signal acquisition.

[0056] Compared with the prior art, the present invention does not require any other external devices and circuits, and can directly provide a reference signal to the AD sampling unit through its own power supply unit, and perform AD sampling based on the reference signal. At the same time, the present invention can also perform multiple sampling through the AD sampling unit to improve the resolution of AD sampling and meet the sampling requirements of higher sampling accuracy.

[0057] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An AD sampling device, comprising an AD sampling unit for collecting a signal to be sampled, and a power supply unit for supplying power to the AD sampling unit, characterized in that: The AD sampling unit further comprises a signal generating unit connected to the AD sampling unit, the signal generating unit being configured to output a reference signal to the AD sampling unit, and the AD sampling unit comparing the signal to be sampled with the reference signal to obtain an AD value; The signal generating unit is connected to the power supply unit and is used to extract the ripple in the power supply unit as the reference signal and output it to the AD sampling unit; The amplitude of the ripple satisfies: V 纹波 ≥(V 电源 *j) / 2 p ; Among them, V 纹波 is the ripple voltage, V 电源 is the output voltage of the power supply unit, p is the fixed sampling bit number of the AD sampling unit, and j is a constant greater than 3.

2. The AD sampling device according to claim 1, characterized in that: The AD value sampled by the AD sampling device is: M= (Vref / V0)*2 p ; Wherein, M is the AD value sampled by the signal to be sampled, Vref is the voltage value of the reference signal, V0 is the voltage value of the signal to be sampled, and p is the fixed sampling bit number of the AD sampling unit.

3. The AD sampling device according to claim 2, characterized in that: When the sampling bit number of the AD sampling device is increased by i bits, the AD sampling unit collects the signal to be sampled multiple times, and the AD value of the signal to be sampled is: M0=(M1+M2+M3+...+M N ) / (N / 2 i ); Wherein, M0 is the AD value of the signal to be sampled when the number of sampling bits of the AD sampling device is increased by i bits, M N is the AD value of the Nth sampling, and i is the number of bits increased by the AD sampling device compared with the fixed sampling bit number of the AD sampling unit.

4. An AD sampling method using the AD sampling device according to any one of claims 1 to 3, characterized in that: include: Output reference signal to AD sampling unit; The AD sampling unit collects the signal to be sampled and the reference signal; The signal to be sampled is compared with the reference signal to obtain an AD value of the signal to be sampled.

5. The AD sampling method according to claim 4, characterized in that: Also includes: Sampling multiple times and obtaining the AD value of the signal to be sampled; The AD value of the signal to be sampled after the number of bits to be increased is calculated according to the number of bits that the AD sampling device needs to increase and the AD value of the signal to be sampled after multiple samplings.

6. The AD sampling method according to claim 5, characterized in that: The sampling times of the signal to be sampled is: N=k*2i, where N is the sampling times, k is a constant greater than 3, and i is the number of bits increased by the AD sampling device compared to the fixed sampling bit number of the AD sampling unit.

7. The AD sampling method according to claim 6, characterized in that: Before sampling multiple times and obtaining the AD value of the signal to be sampled, it is also necessary to determine the type of the reference signal. When the reference signal is a fluctuating signal, the total time of multiple sampling of the signal to be sampled is set to be equal to the period of the reference signal.

8. The AD sampling method according to claim 7, characterized in that: When the total time of the AD sampling is not equal to the period of the reference signal, the operating frequency of the power supply unit is adjusted until the total time of multiple samplings of the signal to be sampled is equal to the period of the reference signal.

9. An electrical appliance, characterized in that The electrical appliance comprises the AD sampling device according to any one of claims 1 to 3, and performs AD sampling on an analog signal of the electrical appliance through the AD sampling device.

10. The electrical appliance according to claim 9, characterized in that The electrical appliance is an air conditioner or a refrigerator, and the analog signal sampled by the AD sampling device is temperature.

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