Double-isolation output DC-DC voltage stabilizing circuit

Abstract

The utility model belongs to the technical field of medical equipment, and particularly relates to a double-isolation output DC-DC voltage stabilizing circuit, in the circuit, a PWM (Pulse Width Modulation) signal passes through a grid isolation driver to output a pulse signal with extremely narrow rising edge and falling edge, after a pulsating waveform is isolated by an isolation transformer, a pulsating level is changed into a direct-current voltage through a rectifier module, and the direct-current voltage is converted into a direct-current voltage. And then a direct-current voltage-stabilized power supply isolated from the input signal is output through the voltage-stabilizing module. Through double isolation of the grid isolation driver and the isolation transformer, the power supply system of the input module and the power supply system of the output module are mutually isolated and do not interfere with each other, and power supply is more stable compared with a traditional power supply module isolated by only one isolation transformer.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to a dual-isolation output DC-DC voltage stabilizing circuit. Background Art

[0002] In modern electronic devices, power management modules play a crucial role. DC-DC converters, as highly efficient power conversion devices, are widely used in various applications requiring a stable and efficient power supply. A DC-DC converter, or direct current-to-direct current converter, is an electronic device that converts one DC voltage to another. It operates by chopping the input DC voltage into a pulse waveform through the high-speed switching action of switching transistors (such as MOSFETs and IGBTs), and then filtering it to obtain the required stable DC output voltage. As a power conversion solution, DC-DC power modules have the following advantages and disadvantages:

[0003] The advantages include: (1) High efficiency: The efficiency of DC-DC power modules is usually very high, reaching over 90%, which helps reduce energy loss and heat generation. (2) Small size and light weight: Compared with traditional transformers and linear regulators, DC-DC power modules are small in size and light in weight, making them very suitable for integration into small devices. (3) Accurate voltage regulation: DC-DC power modules can accurately control the output voltage to meet the voltage requirements of different devices. (4) Fast response speed: Due to the use of switching regulation, DC-DC power modules have a fast response speed and are suitable for applications with high requirements for power supply stability. (5) Adjustable output: Some DC-DC power modules can provide adjustable output voltage through adjustment circuits, which increases flexibility. (6) Wide adaptability: Able to handle a variety of input voltage and output voltage combinations, suitable for various application scenarios. (7) Low cost: Compared with linear regulators and transformers, the manufacturing cost of DC-DC power modules is relatively low.

[0004] The disadvantages include: (1) EMI interference: Since high-frequency switching can cause electromagnetic interference (EMI), effective EMI filtering design is required. (2) Output ripple: The output voltage of the DC-DC power module may have a certain amount of ripple, which needs to be reduced through design and filtering. (3) High design sensitivity: For certain specific applications, such as high-precision analog circuits, the DC-DC power module may require a more complex design to ensure stability and accuracy.

[0005] To address the shortcomings of DC-DC power modules, existing solutions include using power modules with isolation capabilities. These modules can isolate the input and output terminals, achieving electrical isolation between the input and output. This power supply solution is particularly suitable for electronic devices because it provides a stable output voltage, unaffected by input power fluctuations, and effectively isolates electrical noise from the input and output terminals, reducing electrical interference. Designing isolation modules to address shortcomings such as electromagnetic interference and ripple in DC-DC modules is crucial. DC-DC isolated power supply solutions are widely used, particularly in industrial automation, where they are commonly used in industrial computers, PLCs, and other industrial equipment. These devices may encounter various electrical noise and interference in industrial environments. Isolated power supplies can effectively isolate these interferences, ensuring normal operation of the equipment. Furthermore, DC-DC isolated power supply modules offer compact size, excellent performance, and ease of use.

[0006] Chinese patent document CN207968330U (201820149321.1) discloses an isolated power supply circuit that uses an auxiliary transformer to generate a PWM waveform to control the switching of a MOS switch. At the same time, it fully utilizes the energy contained in the PWM waveform, converting the energy into a DC power supply through diodes and capacitors, and then supplies power to the secondary side devices of the transformer. When PWM is generated, the signal is isolated by the transformer and an isolated power supply is generated at the same time. However, the above circuit drives the transformer by turning on and off a transistor or MOS tube. The PWM wave passing through the MOS tube or transistor is prone to forming a high rising edge, which can easily increase the leakage inductance of the transformer and cause large electromagnetic interference, thus affecting the front-end power supply circuit. Utility Model Content

[0007] The purpose of the utility model is to provide a dual-isolated output DC-DC voltage regulator circuit. The utility model discloses a circuit that outputs an isolated regulated power supply with strong anti-interference and small ripple by a gate isolation driver plus a transformer through a DCDC voltage regulator. The circuit is suitable for various circuits requiring a DC regulated power supply, such as high-frequency circuits, power supply circuits, power amplifier circuits, digital circuits, etc., which have high requirements for power supply stability and anti-interference.

[0008] The technical problem to be solved by the present utility model is achieved by adopting the following technical solution: a dual-isolated output DC-DC voltage stabilizing circuit, located between an input module and an output module, comprising a gate isolation driver, an isolation transformer, a rectifier module and a voltage stabilizing module;

[0009] The gate isolation driver is used to process the PWM signal and output a pulse signal;

[0010] The pulse signal is isolated by an isolation transformer and then converted into a DC voltage by a rectifier module;

[0011] The DC voltage is output through a voltage stabilizing module.

[0012] Preferably, the isolation transformer of the present invention is an isolation step-up transformer.

[0013] Preferably, the rectifier module of the present invention is a rectifier diode, and 1N4148 or 1N4007 can be selected.

[0014] Preferably, the voltage stabilizing module is a three-terminal voltage stabilizing circuit module. 78L05, 78L06, and other series three-terminal voltage stabilizing circuit modules have low noise, high ripple rejection ratio, overcurrent, overheating, and short-circuit protection, and are suitable for various application scenarios requiring a stable power supply.

[0015] In the present invention, the gate isolation driver is preferably a MIC4451. The MIC4451 selected as the gate isolation driver has a characteristic of large output current.

[0016] In the preferred embodiment of the present invention, a PWM signal drives multiple gate isolation drivers. A PWM wave circuit is connected to multiple gate isolation drivers, that is, multiple dual-isolated output DC-DC voltage regulator circuits, and can control multiple gate isolation drivers to output different regulated power supplies.

[0017] The inventive concept of the utility model: This design addresses the shortcomings of the existing technology. On the basis of the existing technology, a PWM wave of the driving current is added through a gate isolation driver to replace the generator to control the on and off of the triode or MOS tube through the PWM wave to drive the transformer. After rectification, the voltage is stabilized by a voltage regulator, so that the input and output power supplies are isolated and do not interfere with each other, the ripple is reduced, and the stability of the ground is increased.

[0018] The double isolation of the utility model is to isolate the PWM wave through the isolation gate and the driver and then through the transformer, and has no specific requirements on the PWM frequency.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: in the circuit of the present invention, the PWM signal outputs a pulse signal with extremely narrow rising and falling edges through the gate isolation driver, the pulsating waveform is isolated by the isolation transformer, the pulsating level is converted into a DC voltage through the rectifier module, and then the DC regulated power supply isolated from the input signal is output through the voltage stabilizing module.

[0020] Through double isolation by the gate isolation driver and the isolation transformer, the power supply system of the input module and the power supply system of the output module are isolated from each other and do not interfere with each other. The power supply is more stable than the traditional power supply module isolated by only one isolation transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a structural diagram of the dual-isolated output DC-DC voltage stabilizing circuit module of the present invention;

[0022] Figure 2 This is a circuit diagram of the dual-isolated output DC-DC voltage stabilizing circuit module of the utility model;

[0023] In the figure, 1 is the gate isolation driver, 2 is the isolation transformer, 3 is the rectifier module, and 4 is the voltage regulator module. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, a dual-isolated output DC-DC voltage stabilizing circuit is located between an input module and an output module, and includes a gate isolation driver 1, an isolation transformer 2, a rectifier module 3 and a voltage stabilizing module 4.

[0026] The gate isolation driver 1 is used to process a PWM signal and output a pulse signal. The PWM signal is generated by a PWM controller or a PWM generator. Any PWM signal is acceptable, and it can also be a PWM signal used to drive other circuits. There is no need to select a dedicated pin to output a PWM signal, and there are no specific requirements for the PWM signal frequency.

[0027] The pulse signal is isolated by the isolation transformer 2 and then converted into a DC voltage by the rectifier module 3 .

[0028] The DC voltage is output through the voltage stabilizing module 4 .

[0029] The isolation transformer 2 is an isolation step-up transformer. The isolation transformer 2 can be made into an isolation step-up transformer, and the turns ratio is designed according to the required voltage. The isolation step-up transformer 2 can also be collectively referred to as an isolation transformer, and the turns ratio is 1:1.

[0030] The rectifier module 3 is a rectifier diode.

[0031] The voltage stabilizing module 4 is a three-terminal voltage stabilizing circuit module.

[0032] The gate isolation driver is MIC4451.

[0033] Preferably, the present invention can drive multiple gate isolation drivers 1 with one PWM signal.

[0034] In this circuit, the gate isolation driver 1 isolates interference and increases the drive current and voltage, preventing the leakage inductance voltage of the circuit's isolation transformer 2 from interfering with the control board controlling the module through ground. This circuit directly rectifies the output DC voltage through the gate isolation driver 1 and isolation transformer 2, which then passes through the voltage regulator module 4 to output the required DC regulated power supply.

[0035] The isolation transformer 2 can prevent the power supply or ripple of the control board input module from interfering with the output voltage, thereby enhancing the anti-interference ability of the output voltage and making the power supply more stable.

[0036] The double isolation of the gate isolation driver 1 and the isolation transformer 2 allows the power supply system of the input module and the power supply system of the output module to be isolated from each other without interfering with each other, which is more stable than the traditional power supply module isolated by only one isolation transformer.

[0037] Traditional isolation transformers require PWM signals to be input through MOS transistors or transistors to complete switching, resulting in complex circuits and high power consumption. The isolation transformer's leakage inductance can be connected in series with the input module, generating high-frequency interference. Furthermore, a single controller must generate a PWM signal to drive each isolation module; otherwise, the power consumption is insufficient and the switching transistor cannot be driven. This circuit directly uses an isolated gate driver 1 instead of a MOS transistor to complete the switching circuit. This reduces circuit complexity. By connecting a single PWM signal circuit to multiple drivers, a single PWM signal can control multiple drivers, achieving different regulated power outputs.

[0038] Moreover, compared with the traditional isolation transformer, in the voltage stabilizing circuit of the present invention, the PWM signal passes through the gate isolation driver 1 to avoid the output signal interfering with the control module, i.e., the PWM controller. Moreover, the circuit is simple, and the PWM waveform of the gate isolation driver can drive multiple gate isolation drivers 1, such as Figure 2 As shown, the MIC4451 used for gate isolation driver 1 (U1) boasts high output current. A wide variety of voltage regulator circuit modules can be used as voltage regulator modules to produce different DC regulated power supplies. For example, three-terminal voltage regulator circuit modules such as the 78L05 and 78L06 series offer low noise, high ripple rejection, and overcurrent, overheating, and short-circuit protection, making them suitable for a variety of applications requiring a stable power supply.

[0039] Working principle:

[0040] like Figure 2As shown, the PWM signal outputs a pulse signal with extremely narrow rising and falling edges through the gate isolation driver 1 (U1). The pulsating waveform is isolated by the isolation step-up transformer 2 (T1), rectified by the rectifier tubes (D1, D2, D3, D4), and then outputs a regulated DC power supply isolated from the input signal through the voltage regulator module 4 (U2).

Claims

1. A dual-isolated output DC-DC voltage regulator circuit, located between an input module and an output module, characterized in that: It includes a gate isolation driver (1), an isolation transformer (2), a rectifier module (3) and a voltage stabilization module (4); The gate isolation driver (1) is used to process the PWM signal and output a pulse signal; The pulse signal is isolated by an isolation transformer (2) and then converted into a direct current voltage by a rectifier module (3); The DC voltage is output through a voltage stabilizing module (4).

2. The dual-isolated output DC-DC voltage stabilizing circuit according to claim 1, characterized in that: The isolation transformer (2) is an isolation step-up transformer.

3. The dual-isolated output DC-DC voltage stabilizing circuit according to claim 1, wherein: The rectifier module (3) is a rectifier diode.

4. The dual-isolated output DC-DC voltage stabilizing circuit according to claim 1, wherein: The voltage stabilizing module (4) is a three-terminal voltage stabilizing circuit module.

5. The dual-isolated output DC-DC voltage stabilizing circuit according to claim 1, characterized in that: The gate isolation driver is MIC4451.

6. The dual-isolated output DC-DC voltage stabilizing circuit according to claim 1, characterized in that: One PWM signal drives multiple gate isolation drivers (1).

Images