CN-122026911-A - Analog-to-digital converter and electronic equipment

CN122026911ACN 122026911 ACN122026911 ACN 122026911ACN-122026911-A

Abstract

The invention discloses an analog-to-digital converter and electronic equipment, which comprise a voltage scaling module, a sampling and holding module, a filtering module, a reference voltage module and an analog-to-digital conversion core circuit, wherein the voltage scaling module is used for receiving a first power supply voltage and outputting a second power supply voltage after filtering the first power supply voltage, the reference voltage module is connected with the filtering module and is used for outputting a reference voltage based on the second power supply voltage, and the analog-to-digital conversion core circuit is used for converting an input voltage after being adapted into a digital output signal based on the reference voltage. The voltage scaling module is arranged in front of the sampling and holding module, the input voltage is adapted to the preset input voltage range, and then the input voltage after being adapted is collected and held, so that sampling errors caused by the fact that the input voltage is superimposed with noise and exceeds the effective input voltage range are avoided, the filtering module is connected with the reference voltage module, the power supply voltage is filtered through the filtering module, the power supply quality is guaranteed due to the fact that the external power supply module is not relied on, and cost is reduced.

Inventors

XIANG ZHIHONG

Assignees

珠海格力电器股份有限公司
珠海零边界集成电路有限公司

Dates

Publication Date: 20260512
Application Date: 20251222

Claims (12)

1. An analog-to-digital converter, the analog-to-digital converter comprising: The voltage scaling module is used for receiving input voltage and adapting the input voltage to a preset input voltage range; the sampling and holding module is connected with the voltage scaling module and used for collecting and holding the input voltage after being adapted; The filtering module is used for receiving the first power supply voltage, filtering the first power supply voltage and outputting a second power supply voltage; The reference voltage module is connected with the filtering module and is used for outputting a reference voltage based on the second power supply voltage; and the analog-to-digital conversion core circuit is respectively connected with the sampling and holding module and the reference voltage module and is used for converting the adapted input voltage into a digital output signal based on the reference voltage.
2. The analog-to-digital converter of claim 1, wherein the voltage scaling module comprises a voltage dividing circuit for receiving an input voltage, dividing the input voltage to fit the preset input voltage range.
3. The analog-to-digital converter of claim 2, wherein the voltage divider circuit comprises a first resistor and a second resistor connected in series; The first resistor is connected with the input voltage, the second resistor is grounded, a node between the first resistor and the second resistor is connected with the sample hold module and used for outputting the input voltage after being adapted, and the resistance values of the first resistor and the second resistor are configured to divide the input voltage so as to be adapted to the preset input voltage range.
4. An analog-to-digital converter according to claim 3, wherein the voltage scaling module further comprises a switching circuit; the switching circuit is connected with the voltage dividing circuit and is used for controlling the input voltage to be directly transmitted to the sample and hold module in a first mode, wherein the first mode is a normal working mode without noise interference; And in a second mode, controlling the input voltage to be divided by the voltage dividing circuit to be adapted to the preset input voltage range, wherein the second mode is an anti-interference mode with noise interference.
5. The analog-to-digital converter of claim 4, wherein the switching circuit comprises a first switch and a second switch; one end of the first switch is arranged between the first resistor and the external input voltage, and the other end of the first switch is arranged between the first resistor and the second resistor; the second switch is arranged between the second resistor and the ground; In the first mode, the first switch is closed and the second switch is opened, so that the input voltage is directly transmitted to the sample-and-hold module via the first switch; in the second mode, the first switch is opened, and the second switch is closed, so that the input voltage is transmitted to the sample-hold module after being divided by the first resistor and the second resistor.
6. The analog-to-digital converter of claim 1, wherein the filtering module comprises a first stage buffer circuit and a second stage buffer circuit; The first-stage buffer circuit is used for receiving the first power supply voltage and performing preliminary filtering on the first power supply voltage; the second-stage buffer circuit is connected with the first-stage buffer circuit and is used for filtering the first power supply voltage after preliminary filtering and outputting the second power supply voltage.
7. The analog-to-digital converter of claim 6, wherein the first stage buffer circuit comprises a first input pair of tubes, a first load tube, and a first tail current source; the first input pair of tubes comprises a first NMOS tube and a second NMOS tube, and the first load tube comprises a first PMOS tube and a second PMOS tube; The source electrode of the first NMOS tube and the source electrode of the second NMOS tube are respectively connected with the first tail current source, the drain electrode of the first NMOS tube is connected with the source electrode of the first PMOS tube, and the drain electrode of the second NMOS tube is connected with the source electrode of the first PMOS tube; the drain electrode of the first PMOS tube and the drain electrode of the second PMOS tube are respectively connected with the first power supply voltage, the grid electrode of the first PMOS tube is connected with the grid electrode of the second PMOS tube, and the source electrode of the first PMOS tube is respectively connected with the grid electrode of the first PMOS tube and the grid electrode of the second PMOS tube.
8. The analog-to-digital converter of claim 7, wherein the second stage buffer circuit comprises a second input pair of tubes, a second load tube, a second tail current source, and a capacitor; The second input pair tube comprises a third NMOS tube and a fourth NMOS tube, and the second load tube comprises a third PMOS tube and a fourth PMOS tube; The source electrode of the third NMOS tube and the source electrode of the fourth NMOS tube are respectively connected with the second tail current source, the grid electrode of the third NMOS tube is connected with the grid electrode of the second NMOS tube, the drain electrode of the third NMOS tube is respectively connected with the source electrode of the third PMOS tube, the grid electrode of the third PMOS tube and the grid electrode of the fourth PMOS tube, the grid electrode of the fourth NMOS tube is connected with the capacitor, and the drain electrode of the fourth NMOS tube is respectively connected with the grid electrode of the fourth NMOS tube and the source electrode of the fourth PMOS tube; The drain electrode of the third PMOS tube is respectively connected with the gate electrode of the third NMOS tube, the gate electrode of the second NMOS tube, the drain electrode of the second NMOS tube and the source electrode of the second PMOS tube, and the drain electrode of the fourth PMOS tube is connected with the drain electrode of the third PMOS tube.
9. The analog-to-digital converter of claim 1, wherein the analog-to-digital conversion core circuit comprises an internal digital-to-analog converter, a comparator, and an output module; the internal digital-to-analog converter is used for generating an analog feedback voltage based on the reference voltage; The comparator is used for comparing the analog feedback voltage with the adapted voltage and outputting a comparison signal; The output module is configured to output a digital output signal determined based on the comparison signal.
10. The analog-to-digital converter of claim 9, wherein the analog-to-digital conversion core circuit further comprises a successive approximation switch control module; The successive approximation switch control module is configured to determine each bit of the digital output signal from a most significant bit to a least significant bit according to the comparison signal, so as to determine a complete digital output signal representing the adapted voltage signal.
11. The analog-to-digital converter of claim 10, wherein the analog-to-digital converter comprises, The successive approximation switch control module is further configured to generate a control signal based on a currently determined digital bit in a bitwise determination process, and send the control signal to the internal digital-to-analog converter, so that the internal digital-to-analog converter adjusts the analog feedback voltage based on the control signal; after the successive approximation of all bits is completed, the digital output signal is sent to the output module.
12. An electronic device comprising an analog-to-digital converter as claimed in any one of claims 1-11.

Description

Analog-to-digital converter and electronic equipment Technical Field The invention belongs to the technical field of analog integrated circuits, and particularly relates to an analog-to-digital converter and electronic equipment. Background In modern industrial control and intelligent motor drive systems, high-precision Analog-to-Digital Converter (ADC) is widely used to collect key Analog signals such as current and voltage, so as to realize accurate closed-loop control. However, during the operation of the motor, due to frequent actions of the high-power switch device, electromagnetic interference (Electromagnetic Interference, EMI) and other factors, strong noise coupling is commonly existed in the system, and particularly the noise coupling is easy to invade the analog-to-digital converter through a power supply, a ground wire and a signal path, so that the sampling precision and the stability of the analog-to-digital converter are seriously affected. At present, an external high-performance power management chip is generally adopted to carry out filtering and voltage stabilization processing on the reference voltage and the power supply voltage of the analog-to-digital converter, a complex digital calibration algorithm is introduced to carry out post-processing on the ADC output code value so as to correct nonlinear errors caused by noise, in addition, the ground reference plane of the analog-to-digital converter is also generally completely isolated from the ground of a motor driving part, and an independent analog ground system is constructed so as to reduce common mode interference. However, if the conventional analog-to-digital converter without the filter circuit is used, in a strong noise environment, the input signal of the analog-to-digital converter is easy to exceed the effective input voltage range due to high frequency or impulse noise, error sampling points are continuously generated during the operation of the motor, the power supply quality of the ADC is ensured by excessively relying on an external power supply module, the coupling dependence of the system on other modules is increased, and the whole hardware cost is increased by an additional power supply management chip. Disclosure of Invention In view of the foregoing, embodiments of the present invention have been developed to provide an analog-to-digital converter and an electronic device that overcome, or at least partially solve, the foregoing problems. In a first aspect, an embodiment of the present invention provides an analog-to-digital converter, including a voltage scaling module, configured to receive an input voltage and adapt the input voltage to a preset input voltage range; the sampling and holding module is connected with the voltage scaling module and used for collecting and holding the input voltage after being adapted; The filtering module is used for receiving the first power supply voltage, filtering the first power supply voltage and outputting a second power supply voltage; The reference voltage module is connected with the filtering module and is used for outputting a reference voltage based on the second power supply voltage; And the analog-to-digital conversion core circuit is respectively connected with the sampling and holding module and the reference voltage module and is used for converting the adapted input voltage into a digital output signal based on the reference voltage. . Optionally, the voltage scaling module includes a voltage dividing circuit, where the voltage dividing circuit is configured to receive an input voltage and divide the input voltage to adapt to the preset input voltage range. Optionally, the voltage dividing circuit includes a first resistor and a second resistor connected in series; The first resistor is connected with the input voltage, the second resistor is grounded, a node between the first resistor and the second resistor is connected with the sample hold module and used for outputting the input voltage after being adapted, and the resistance values of the first resistor and the second resistor are configured to divide the input voltage so as to be adapted to the preset input voltage range. Optionally, the voltage scaling module further comprises a switching circuit; the switching circuit is connected with the voltage dividing circuit and is used for controlling the input voltage to be directly transmitted to the sample and hold module in a first mode, wherein the first mode is a normal working mode without noise interference; And in a second mode, controlling the input voltage to be divided by the voltage dividing circuit to be adapted to the preset input voltage range, wherein the second mode is an anti-interference mode with noise interference. Optionally, the switching circuit includes a first switch and a second switch; one end of the first switch is arranged between the first resistor and the external input voltage, and the other end of the first switch is arranged betw