Voltage feedback control circuit based on DAC high-precision digital-to-analog conversion

Abstract

The utility model relates to the technical field of electronic circuits, and discloses a voltage feedback control circuit based on DAC high-precision digital-to-analog conversion, comprising a DAC module; a voltage sampling module; a voltage feedback control loop; an operational amplifier module; a power supply module; the DAC module adopts a high-precision chip, errors in the digital-to-analog conversion process can be remarkably reduced, it is ensured that a generated analog voltage signal accurately reflects expected voltage, and therefore high-precision voltage feedback control is achieved; the voltage sampling module and the voltage feedback control loop work cooperatively, so that the voltage can be monitored and adjusted accurately in real time; the voltage deviation is quickly and effectively adjusted, so that the output voltage can be quickly stabilized in an expected range, and the problem of inaccurate voltage control of a traditional circuit is solved; precise feedback control of the voltage is realized by combining a plurality of functional modules, and the stability and accuracy of voltage output of the electronic equipment can be effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, specifically a voltage feedback control circuit based on DAC high-precision digital-to-analog conversion. Background Technology

[0002] Electronic circuits refer to circuits composed of electronic devices and related radio components. They include circuits for amplification, oscillation, rectification, detection, modulation, frequency conversion, waveform conversion, and various control circuits. Precise voltage control is crucial for the performance of electronic equipment during operation.

[0003] A search revealed that patent application number CN201811492395.6 discloses a voltage feedback control circuit, belonging to the field of voltage feedback control. This invention achieves rapid sampling of the output voltage through a voltage sampling circuit, sending the sampled output voltage to an automatic gain amplifier circuit. Through automatic gain amplification control, the transmission ratio of the isolation transmission circuit is adjusted, thereby adjusting the duty cycle of the pulse width modulator, achieving high-precision and rapid voltage regulation control of the output power supply. Simultaneously, a bias acceleration control circuit sensitively monitors voltage changes at the output terminal, enabling rapid dynamic adjustment of the output. This invention employs a fast-response voltage sampling circuit, avoiding the problem of insufficient dynamic transient response of voltage; it uses automatic gain feedback control technology to improve output voltage accuracy and effectively eliminate high-frequency oscillations; and it uses a bias acceleration drive circuit to improve output adjustment capability and avoid output overshoot.

[0004] Traditional voltage feedback circuits suffer from deficiencies in digital-to-analog conversion accuracy, stability, and circuit complexity. These shortcomings lead to inaccurate voltage control, affecting the normal operation and performance of equipment. Therefore, we need to propose a voltage feedback control circuit based on high-precision digital-to-analog conversion (DAC) to solve these problems through a high-precision and stable voltage feedback circuit. Utility Model Content

[0005] The purpose of this invention is to provide a voltage feedback control circuit based on high-precision digital-to-analog conversion (DAC) to achieve high-precision voltage feedback control, enhance the stability of voltage output of electronic devices, and overcome the defects of traditional circuits, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a voltage feedback control circuit based on high-precision digital-to-analog conversion (DAC), comprising:

[0007] A DAC module that converts digital signals into analog signals;

[0008] A voltage sampling module responsible for acquiring voltage signals;

[0009] A voltage feedback control loop that provides feedback control over the voltage;

[0010] Operational amplifier module for amplifying and processing signals;

[0011] A power supply module that is electrically connected to the DAC module, voltage sampling module, voltage feedback control loop, and operational amplifier module and provides a stable power supply;

[0012] The voltage sampling module, voltage feedback control loop, and operational amplifier module are all electrically connected to the DAC module, and the voltage feedback control loop is electrically connected to the operational amplifier module.

[0013] Preferably, the power module includes a voltage reference chip D1 and a power chip U1. Pin 2 of the voltage reference chip D1 is connected to pin 1 of the power chip U1. A capacitor C1 and a capacitor C2 are connected in parallel between pins 2 and 4 of the voltage reference chip D1. A grounded capacitor C3 is connected to pin 6 of the voltage reference chip D1. A capacitor C6 is connected between pins 1 and 2 of the power chip U1. A capacitor C4 is connected to pin 7 of the power chip U1. A capacitor C5 is connected to pin 5 of the power chip U1.

[0014] Preferably, the DAC module includes analog-to-digital converter chip D2 and analog-to-digital converter chip D3. Pin 13 of both analog-to-digital converter chip D2 and analog-to-digital converter chip D3 are connected to a 5V power supply. Pins IOUTA and IOUTB of analog-to-digital converter chip D2 and analog-to-digital converter chip D3 output analog current signals.

[0015] Preferably, the voltage sampling module includes connector XS1, amplifier AJ1, chip U2, and amplifier AJ2. Pin 7 of amplifier AJ1 and pin 1 of chip U2 are both connected to pin 7 of power chip U1. Pin 4 of amplifier AJ1 is connected to pin 5 of power chip U1. Pin 6 of amplifier AJ2 is connected to pin 7 of analog-to-digital converter chip D3.

[0016] Resistors R14, R15, R16, and R9 are connected in series between pin 1 of connector XS1 and pin 2 of amplifier AJ1, and resistors R1, R2, R3, and R7 are connected in series between pin 4 of connector XS1 and pin 3 of amplifier AJ1.

[0017] A capacitor C15 and a resistor R4 are connected in parallel to pin 3 of amplifier AJ1. A capacitor C24 and a resistor R17 are connected in parallel between pins 2 and 6 of amplifier AJ1. Pin 6 of amplifier AJ1 is connected to pin 2 of chip U2.

[0018] Preferably, a capacitor C18 is connected between pins 1 and 4 of chip U2, a capacitor C19 is connected between pins 5 and 8 of chip U2, a resistor R8 and a resistor R10 are connected in series between pin 7 of chip U2 and pin 3 of amplifier AJ2, a resistor R11 and a resistor R12 are connected in series between pin 6 of chip U2 and pin 2 of amplifier AJ2, a capacitor C16 and a resistor R5 are connected in parallel to pin 3 of amplifier AJ2, and a capacitor C25 and a resistor R18 are connected in parallel between pins 2 and 6 of amplifier AJ2.

[0019] Preferably, the voltage feedback control loop includes amplifier AJ3 and amplifier AJ4. A capacitor C29 is connected between pins 2 and 6 of amplifier AJ3. Resistors R21 and R28 are also connected to pin 2 of amplifier AJ3. Resistor R21 is connected to pin 8 of analog-to-digital converter chip D3. A closed-loop resistor R19, resistor R26, and potentiometer VR1 are connected to pin 6 of amplifier AJ3. A resistor R23 is connected between potentiometer VR1 and pin 2 of amplifier AJ3.

[0020] Preferably, a capacitor C30 and a resistor R25 are connected in parallel between pins 2 and 6 of amplifier AJ4, a resistor R29 is connected between pin 2 of amplifier AJ4 and pin 6 of amplifier AJ3, and a resistor R24 ​​is also connected to pin 2 of amplifier AJ4. The resistor R24 ​​is connected to pin 1 of analog-to-digital converter chip D3.

[0021] Preferably, the operational amplifier module includes amplifier U3A and amplifier U4B. Pin 2 of amplifier U3A is connected to pin 3 of analog-to-digital converter chip D2. Resistor R28 is connected to pin 7 of amplifier U4B. Resistor R27 is connected between pin 1 of amplifier U3A and pin 6 of amplifier U4B. Capacitor C27 is connected between pin 1 and pin 2 of amplifier U3A. Capacitor C28 and resistor R20 are connected in parallel between pin 6 and pin 7 of amplifier U4B. Resistor R22 is also connected to pin 6 of amplifier U4B. Resistor R22 is connected to pin 3 of voltage reference chip D1.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] 1. The DAC module of this utility model adopts a high-precision chip with high resolution and low nonlinearity, which can significantly reduce the error in the digital-to-analog conversion process and ensure that the generated analog voltage signal accurately reflects the desired voltage, thereby realizing high-precision voltage feedback control;

[0024] 2. This utility model effectively reduces the impact of unstable factors such as power supply noise and circuit self-oscillation through the decoupling capacitor design in the power supply module and the reasonable connection between each module. While ensuring high-precision feedback, it greatly improves the stability of the circuit and ensures reliable operation even in complex working environments;

[0025] 3. The coordinated operation of the voltage sampling module and voltage feedback control loop of this utility model enables real-time and accurate monitoring and adjustment of voltage; based on precise comparison and control algorithms, it can quickly and effectively adjust voltage deviation, so that the output voltage can be quickly stabilized within the expected range, thus solving the problem of inaccurate voltage control in traditional circuits.

[0026] 4. The circuit structure of this utility model is reasonably designed, and the functions of each module are clearly defined, making it easy to integrate into existing electronic systems. At the same time, the modular design facilitates circuit maintenance and upgrades. By adjusting the parameters of key module components, the voltage feedback control requirements of different application scenarios can be easily met. Attached Figure Description

[0027] Figure 1 This is a circuit diagram of the power supply module of this utility model;

[0028] Figure 2 This is the circuit diagram of the DAC module of this utility model;

[0029] Figure 3 This is a circuit diagram of the voltage sampling module of this utility model;

[0030] Figure 4 This is the circuit diagram of the voltage feedback control loop of this utility model;

[0031] Figure 5 This is the circuit diagram of the operational amplifier module of this utility model. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Please see Figures 1-5 This utility model provides a technical solution: a voltage feedback control circuit based on DAC high-precision digital-to-analog conversion, comprising:

[0034] A DAC module that converts digital signals into analog signals;

[0035] The DAC module includes analog-to-digital converter chip D2 and analog-to-digital converter chip D3. Pin 13 of both analog-to-digital converter chip D2 and analog-to-digital converter chip D3 are connected to a 5V power supply. Pins IOUTA and IOUTB of analog-to-digital converter chip D2 and analog-to-digital converter chip D3 output analog current signals.

[0036] Both analog-to-digital converter (ADC) chips D2 and D3 use the AD5545BRU as the core component of the DAC module. The pins of ADC chips D2 and D3 are connected to a microcontroller or other related circuits to receive digital signals and perform digital-to-analog conversion. ADC chips D2 and D3 are based on an R-2R architecture; their internal resistor network outputs analog current signals based on the input digital signal, such as the IOUTA and IOUTB pins.

[0037] The analog-to-digital converter chips D2 and D3 are equipped with serial data input (SDI), clock (CLK), and chip select (CS) pins. These pins are used for accurate data communication with the microcontroller to receive and convert digital signals.

[0038] A voltage sampling module responsible for acquiring voltage signals;

[0039] The voltage sampling module includes connector XS1, amplifier AJ1, chip U2, and amplifier AJ2. Pin 7 of amplifier AJ1 and pin 1 of chip U2 are both connected to pin 7 of power chip U1. Pin 4 of amplifier AJ1 is connected to pin 5 of power chip U1. Pin 6 of amplifier AJ2 is connected to pin 7 of analog-to-digital converter chip D3.

[0040] Resistors R14, R15, R16, and R9 are connected in series between pin 1 of connector XS1 and pin 2 of amplifier AJ1, and resistors R1, R2, R3, and R7 are connected in series between pin 4 of connector XS1 and pin 3 of amplifier AJ1.

[0041] A capacitor C15 and a resistor R4 are connected in parallel to pin 3 of amplifier AJ1. A capacitor C24 and a resistor R17 are connected in parallel between pins 2 and 6 of amplifier AJ1. Pin 6 of amplifier AJ1 is connected to pin 2 of chip U2.

[0042] A capacitor C18 is connected between pins 1 and 4 of chip U2; a capacitor C19 is connected between pins 5 and 8 of chip U2; a resistor R8 and a resistor R10 are connected in series between pin 7 of chip U2 and pin 3 of amplifier AJ2; a resistor R11 and a resistor R12 are connected in series between pin 6 of chip U2 and pin 2 of amplifier AJ2; a capacitor C16 and a resistor R5 are connected in parallel to pin 3 of amplifier AJ2; and a capacitor C25 and a resistor R18 are connected in parallel between pins 2 and 6 of amplifier AJ2.

[0043] The voltage sampling module consists of multiple resistors, capacitors, and related connection circuits. For example, it uses resistors of specific resistance values ​​to perform voltage division sampling, and capacitors to filter the sampled signal, ensuring that the acquired voltage signal is accurate and stable.

[0044] A voltage feedback control loop that provides feedback control over the voltage;

[0045] The voltage feedback control loop includes amplifiers AJ3 and AJ4. A capacitor C29 is connected between pins 2 and 6 of amplifier AJ3. Resistors R21 and R28 are also connected to pin 2 of amplifier AJ3. Resistor R21 is connected to pin 8 of analog-to-digital converter chip D3. Closed-loop resistors R19 and R26 and potentiometer VR1 are connected to pin 6 of amplifier AJ3. Resistor R23 is connected between potentiometer VR1 and pin 2 of amplifier AJ3.

[0046] A capacitor C30 and a resistor R25 are connected in parallel between pins 2 and 6 of amplifier AJ4. A resistor R29 is connected between pin 2 of amplifier AJ4 and pin 6 of amplifier AJ3. A resistor R24 ​​is also connected to pin 2 of amplifier AJ4. The resistor R24 ​​is connected to pin 1 of analog-to-digital converter chip D3.

[0047] The voltage feedback control loop consists of a comparator, an operational amplifier, and related control circuitry. The voltage signal acquired by the voltage sampling module is compared with a preset reference voltage in the comparator. The resulting deviation signal is processed by the operational amplifier and related control circuitry, and an adjusted digital signal is generated according to a preset control algorithm and fed back to the DAC module.

[0048] The voltage feedback control loop is a crucial component for achieving precise voltage control. It receives the voltage signal from the voltage sampling module and compares it with a preset reference voltage. Based on the deviation generated by the comparison, a specific control algorithm adjusts the digital signal, and the adjusted digital signal is fed back to the DAC module, thus achieving precise voltage control. In addition, the voltage feedback control loop circuit uses a potentiometer to arbitrarily adjust the gain of the voltage loop.

[0049] Operational amplifier module for amplifying and processing signals;

[0050] The operational amplifier module includes amplifier U3A and amplifier U4B. Pin 2 of amplifier U3A is connected to pin 3 of analog-to-digital converter chip D2. Resistor R28 is connected to pin 7 of amplifier U4B. Resistor R27 is connected between pin 1 of amplifier U3A and pin 6 of amplifier U4B. Capacitor C27 is connected between pin 1 and pin 2 of amplifier U3A. Capacitor C28 and resistor R20 are connected in parallel between pin 6 and pin 7 of amplifier U4B. Resistor R22 is also connected to pin 6 of amplifier U4B. Resistor R22 is connected to pin 3 of voltage reference chip D1.

[0051] Amplifiers U3A and U4B both use the model OPA2277UAM / TR. The analog current signal output by the DAC module is connected to the input pins of amplifiers U3A and U4B through an external resistor. Amplifiers U3A and U4B convert the current signal into a voltage signal, such as DA_OUTA and DA_OUTB, based on their virtual short and virtual open characteristics.

[0052] The operational amplifier (op-amp) module converts the analog current signal output from the DAC module into a voltage signal. By properly designing the op-amp module's peripheral circuitry, the accuracy and stability of the signal conversion are ensured.

[0053] A power supply module that is electrically connected to the DAC module, voltage sampling module, voltage feedback control loop, and operational amplifier module and provides a stable power supply;

[0054] The power module includes a voltage reference chip D1 and a power chip U1. Pin 2 of the voltage reference chip D1 is connected to pin 1 of the power chip U1. Capacitors C1 and C2 are connected in parallel between pins 2 and 4 of the voltage reference chip D1. A grounded capacitor C3 is connected to pin 6 of the voltage reference chip D1. A capacitor C6 is connected between pins 1 and 2 of the power chip U1. A capacitor C4 is connected to pin 7 of the power chip U1. A capacitor C5 is connected to pin 5 of the power chip U1.

[0055] In the power module, you can see multiple power input and output points, such as ±15V and +5V markings. There are also decoupling capacitors connected near key components. For example, capacitors with specific capacitance values ​​are connected near the power pins of certain chips. These decoupling capacitors play a role in filtering out power supply noise and ensuring the stability of the power supply.

[0056] The voltage sampling module, voltage feedback control loop, and operational amplifier module are all electrically connected to the DAC module, and the voltage feedback control loop is electrically connected to the operational amplifier module.

[0057] The operation of the voltage feedback control circuit in this application is as follows:

[0058] First, the microcontroller generates the corresponding digital signal according to the set voltage control strategy, and transmits the digital signal to the internal register of the AD5545BRU chip through the SDI, CLK and CS pins of the DAC module.

[0059] Next, the AD5545BRU chip performs digital-to-analog conversion based on its internal R-2R architecture, and its IOUTA and IOUTB pins output analog current signals.

[0060] Then, the operational amplifier module converts the analog current signal into a voltage signal. Simultaneously, the voltage sampling module acquires this voltage signal and transmits it to the voltage feedback control loop.

[0061] Finally, the voltage feedback control loop compares the acquired voltage signal with a preset reference voltage to generate a deviation signal. This deviation signal is processed, and the digital signal is adjusted according to a preset control algorithm. It is then converted from digital to analog and further processed by the DAC module. This process is repeated until the voltage reaches a stable state, achieving precise voltage feedback control.

[0062] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A voltage feedback control circuit based on high-precision digital-to-analog conversion of DAC, characterized in that, Include: The DAC module converts digital signal to analog signal; The voltage sampling module is responsible for collecting voltage signal; The voltage feedback control loop controls the voltage feedback; The operational amplifier module amplifies the signal; The power module is electrically connected with the DAC module, the voltage sampling module, the voltage feedback control loop and the operational amplifier module, and provides stable power supply; The voltage sampling module, the voltage feedback control loop and the operational amplifier module are electrically connected with the DAC module, and the voltage feedback control loop is electrically connected with the operational amplifier module.

2. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 1, characterized in that: The power module includes voltage reference chip D1 and power chip U1, the 2th pin of the voltage reference chip D1 is connected with the 1st pin of the power chip U1, the 2th pin and the 4th pin of the voltage reference chip D1 are connected with the parallelly arranged capacitor C1 and capacitor C2, the 6th pin of the voltage reference chip D1 is connected with the ground capacitor C3, the 1st pin and the 2nd pin of the power chip U1 are connected with the capacitor C6, the 7th pin of the power chip U1 is connected with the capacitor C4, and the 5th pin of the power chip U1 is connected with the capacitor C5.

3. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 2, characterized in that: The DAC module includes analog-to-digital conversion chip D2 and analog-to-digital conversion chip D3, the 13th pin of the analog-to-digital conversion chip D2 and the 13th pin of the analog-to-digital conversion chip D3 are connected with 5V power supply, and the IOUTA pin and the IOUTB pin of the analog-to-digital conversion chip D2 and the analog-to-digital conversion chip D3 output analog current signal.

4. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 3, characterized in that: The voltage sampling module includes connector XS1, amplifier AJ1, chip U2 and amplifier AJ2, the 7th pin of the amplifier AJ1 and the 1st pin of the chip U2 are connected with the 7th pin of the power chip U1, the 4th pin of the amplifier AJ1 is connected with the 5th pin of the power chip U1, and the 6th pin of the amplifier AJ2 is connected with the 7th pin of the analog-to-digital conversion chip D3. The 1st pin of the connector XS1 and the 2nd pin of the amplifier AJ1 are connected in series with the resistor R14, the resistor R15, the resistor R16 and the resistor R9, and the 4th pin of the connector XS1 and the 3rd pin of the amplifier AJ1 are connected in series with the resistor R1, the resistor R2, the resistor R3 and the resistor R7. The 3rd pin of the amplifier AJ1 is further connected with the parallelly arranged capacitor C15 and resistor R4, the 2nd pin and the 6th pin of the amplifier AJ1 are connected with the parallelly arranged capacitor C24 and resistor R17, and the 6th pin of the amplifier AJ1 is connected with the 2nd pin of the chip U2.

5. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 4, characterized in that: The 1st pin and the 4th pin of the chip U2 are connected with the capacitor C18, the 5th pin and the 8th pin of the chip U2 are connected with the capacitor C19, the 7th pin of the chip U2 and the 3rd pin of the amplifier AJ2 are connected in series with the resistor R8 and the resistor R10, the 6th pin of the chip U2 and the 2nd pin of the amplifier AJ2 are connected in series with the resistor R11 and the resistor R12, the 3rd pin of the amplifier AJ2 is connected with the parallelly arranged capacitor C16 and resistor R5, and the 2nd pin and the 6th pin of the amplifier AJ2 are connected with the parallelly arranged capacitor C25 and resistor R18.

6. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 5, characterized in that: The voltage feedback control loop comprises an amplifier AJ3 and an amplifier AJ4, a capacitor C29 is connected between the 2nd pin and the 6th pin of the amplifier AJ3, a resistor R21 and a resistor R28 are further connected to the 2nd pin of the amplifier AJ3, the resistor R21 is connected to the 8th pin of an analog-digital conversion chip D3, a closed loop resistor R19, a resistor R26 and a potentiometer VR1 are connected to the 6th pin of the amplifier AJ3, and a resistor R23 is connected between the potentiometer VR1 and the 2nd pin of the amplifier AJ3.

7. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 6, characterized in that: A capacitor C30 and a resistor R25 are connected in parallel between the 2nd pin and the 6th pin of the amplifier AJ4, a resistor R29 is connected between the 2nd pin of the amplifier AJ4 and the 6th pin of the amplifier AJ3, a resistor R24 is further connected to the 2nd pin of the amplifier AJ4, and the resistor R24 is connected to the 1st pin of the analog-digital conversion chip D3.

8. The voltage feedback control circuit based on DAC high-precision digital-to-analog conversion according to claim 7, characterized in that: The operational amplifier module comprises an amplifier U3A and an amplifier U4B, the 2nd pin of the amplifier U3A is connected to the 3rd pin of an analog-digital conversion chip D2, the resistor R28 is connected to the 7th pin of the amplifier U4B, a resistor R27 is connected between the 1st pin of the amplifier U3A and the 6th pin of the amplifier U4B, a capacitor C27 is connected between the 1st pin and the 2nd pin of the amplifier U3A, a capacitor C28 and a resistor R20 are connected in parallel between the 6th pin and the 7th pin of the amplifier U4B, a resistor R22 is further connected to the 6th pin of the amplifier U4B, and the resistor R22 is connected to the 3rd pin of a voltage reference chip D1.

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