Voltage output structure with current limiting protection

Abstract

The utility model discloses a voltage output structure with current -limiting protection relates to the field of external output interface. This voltage output structure with current -limiting protection, including input voltage VIN, output voltage VOUT, voltage output structure and microcontroller unit. This voltage output structure with current -limiting protection, utilize discrete component to realize the protection of voltage output interface, switch enable and protection, adopt discrete component technology cost is low, and the abundant resource of microcontroller unit is combined simultaneously, can effectively monitor output state, can realize a variety of control strategy, and this circuit structure can pass through the parameter of sampling resistance R1 and triode Q1, and the flexible adjustment current -limiting current and output capacity, can adapt to a variety of output requirements, and the voltage protection device of interface is stabilized diode DZ1, plays the protection of voltage pulse and the ESD of external interface.

Description

Technical Field

[0001] This utility model relates to the field of external output interface technology, specifically a voltage output structure with current limiting protection. Background Technology

[0002] In the design of automotive electronic equipment, there are high protection requirements for the external output interfaces, especially for the I / O ports of the external output voltage. It is necessary to consider abnormal situations such as external device malfunctions, current overloads, shorting to the external 12V power supply, and shorting to ground. In such cases, it is necessary to protect the internal power supply of the device itself from interference that could cause damage or affect the normal operation of the device, and also to prevent damage to the peripheral devices.

[0003] For example, the external electret microphone interface in the TBOX product design needs to provide a 5V operating power supply to the external microphone. The normal operating current is less than 100mA. Existing technology uses a dedicated power conversion chip, such as an LDO, as the power output, or a fuse for protection. However, LDOs are expensive and inflexible in application, while fuse protection is non-resettable.

[0004] Existing designs primarily use dedicated basic circuit chips as output interface drivers or simple switching circuits, lacking current limiting and ESD protection. This application utilizes discrete components, making it suitable for various operating conditions and scenarios. Parameter adjustments cater to both low-current and high-current applications. It features output current limiting protection, output reverse connection protection, and current backflow protection. With software integration, safety protection can be achieved. The aim is to provide a simple, low-cost, widely applicable interface control circuit with current limiting, ESD protection, and output switch control. Current limiting adjustments are convenient, and it is suitable for various protection scenarios. It can effectively integrate with microcontrollers to design effective interface protection and monitoring strategies. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a voltage output structure with current limiting protection. This solves the problems of using an LDO as the power supply output on the external output voltage I / O port, or using a fuse for protection, to prevent the internal power supply of the device from being disturbed and damaged or affecting the normal operation of the device. However, LDOs are expensive and inflexible in application, and fuse protection is not reversible.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a voltage output structure with current limiting protection, comprising: The input voltage VIN is connected to the internal regulated power supply. The output voltage VOUT is connected to an external load module. The voltage output structure is connected to the input voltage VIN and the output voltage VOUT. The voltage output structure is equipped with a sampling resistor R1, a transistor Q1 and a transistor Q2. The sampling resistor R1 is connected to the transistor Q1, and the transistor Q2 is connected in parallel with the sampling resistor R1. The voltage output structure of the microcontroller unit is fed back to the microcontroller unit, and the microcontroller unit enables the voltage output structure. A diode D1 is connected in series between the input voltage VIN and the output voltage VOUT, and a Zener diode DZ1 is provided between the diode D1 and the output voltage VOUT.

[0007] Preferably, the sampling resistor R1 is connected to the input voltage VIN.

[0008] Preferably, transistors Q1 and Q2 and sampling resistor R1 form a current-limiting protection output circuit.

[0009] Preferably, a transistor Q3, resistor R5, and resistor R6 are connected in series with the sampling resistor R1, forming a feedback control enable circuit.

[0010] Preferably, resistor R4 and transistor Q3 form the enable control circuit for transistor Q1.

[0011] Preferably, the base of transistor Q1 is connected to capacitor C1, and resistors R7 and R8 are connected in parallel on capacitor C1.

[0012] Preferably, resistors R7 and R8 form a voltage divider acquisition circuit for the output voltage.

[0013] Its beneficial effects are as follows: This voltage output structure with current limiting protection utilizes discrete components to protect the voltage output interface, enable and protect the switch. The use of discrete component technology results in low cost, and combined with the abundant resources of the microcontroller unit, it can effectively monitor the output status and implement various control strategies. This circuit structure can flexibly adjust the current limiting current and output capability by adjusting the parameters of the sampling resistor R1 and the transistor Q1, and can adapt to various output requirements. The Zener diode DZ1 is an interface voltage protection device, which protects against voltage pulses and ESD of the external interface. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the overall structure of this embodiment; Figure 2 This is a schematic diagram of the voltage output structure in this embodiment. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model are described clearly and completely. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0018] This utility model discloses a voltage output structure with current limiting protection, according to the attached... Figure 1 As shown, it includes: The input voltage VIN is connected to the internal regulated power supply. The voltage varies depending on the output application and can be set to 12V, 5V, etc., as required.

[0019] The output voltage VOUT is connected to an external load module, such as an external electret microphone which requires a 5V power supply.

[0020] The voltage output structure is connected to the input voltage VIN and the output voltage VOUT. The voltage output structure includes a sampling resistor R1, a transistor Q1, and a transistor Q2. The sampling resistor R1 is connected to the transistor Q1, and the transistor Q2 is connected in parallel with the sampling resistor R1. Furthermore, a current-limiting protection output circuit is formed using transistors Q1 and Q2 and sampling resistor R1.

[0021] The microcontroller unit has a voltage output structure. The voltage is fed back to the microcontroller unit, and the microcontroller unit enables the voltage output structure.

[0022] It is particularly important to note that the protection, switch enablement, and protection of the voltage output interface are achieved using discrete components. The use of discrete component technology results in low cost, and combined with the abundant resources of the microcontroller unit, the output status can be effectively monitored, and various control strategies can be implemented. This circuit structure can flexibly adjust the current limiting current and output capability by adjusting the parameters of the sampling resistor R1 and the transistor Q1, and can adapt to various output requirements.

[0023] A diode D1 is connected in series between the input voltage VIN and the output voltage VOUT, and a Zener diode DZ1 is provided between the diode D1 and the output voltage VOUT.

[0024] Furthermore, diode D1 is used to implement reverse connection protection of the output, preventing reverse voltage from damaging the circuit. Zener diode DZ1, in conjunction with diode D1, provides comprehensive protection, defending against both forward and reverse overvoltage.

[0025] Zener diode DZ1 is an interface voltage protection device that protects against voltage pulses and ESD damage to external interfaces.

[0026] According to the appendix Figure 2 As shown, a transistor Q2 is connected in parallel with the sampling resistor R1, and a resistor R2 is connected between the transistor Q2 and the sampling resistor R1.

[0027] Furthermore, the current flows from VIN through the sampling resistor R1 to generate a voltage drop, which serves as a control feedback signal. The voltage drop across the sampling resistor R1 controls the voltage of the transistor Q2. Specifically disclosed, the on-state voltage drop and on-state current of transistor Q1 are controlled by the circuit composed of sampling resistor R1 and transistor Q2. When the current exceeds the limit value, the voltage drop across sampling resistor R1 is at its maximum, the conduction of transistor Q2 increases, the conduction of transistor Q2 decreases, the gate voltage of transistor Q1 increases, the voltage difference Vgs of transistor Q1 decreases, the on-resistance of transistor Q1 increases, and the on-state voltage drop of transistor Q1 increases, thereby limiting the output current.

[0028] A transistor Q3, resistor R5, and resistor R6 are connected in series with the sampling resistor R1. The series transistor Q3, resistor R5, and resistor R6 form a feedback control enable circuit. The controller enables and disables the voltage output through the transistor Q3 circuit.

[0029] Resistor R4 and transistor Q3 form the enable control circuit for transistor Q1. This circuit controls the output voltage VOUT of the microcontroller unit and enables or disables it.

[0030] The base of transistor Q1 is connected to capacitor C1, and resistors R7 and R8 are connected in parallel across capacitor C1.

[0031] The output feedback circuit, composed of capacitor C1, resistor R7, and resistor R8, feeds back to the ADC (analog-to-digital converter) port of the microcontroller unit to effectively monitor the operating status of the output circuit and enable real-time control strategies. Combined with software logic, this allows for flexible and effective interface control and protection strategies.

[0032] Resistors R7 and R8 form a voltage divider acquisition circuit for the output voltage. The acquired output voltage is fed back to the microcontroller unit for software processing and judgment. The software can achieve effective control and protection for various states through algorithms.

[0033] Working principle: The input voltage VIN is connected to the internal regulated power supply.

[0034] The output voltage VOUT is connected to an external load module.

[0035] Current flows from the input voltage VIN through the sampling resistor R1 to generate a voltage drop, which serves as a control feedback signal. The voltage drop across the sampling resistor R1 controls the voltage of the transistor Q2.

[0036] The on-state voltage drop and on-state current of transistor Q1 are controlled by the circuit composed of sampling resistor R1 and transistor Q2. When the current exceeds the limit, the voltage drop across sampling resistor R1 is at its maximum, the conduction of transistor Q2 increases, the conduction of transistor Q2 decreases, the gate voltage of transistor Q1 increases, the VGS voltage difference of transistor Q1 decreases, the on-resistance of transistor Q1 increases, and the on-state voltage drop of transistor Q1 increases, thereby limiting the output current.

[0037] Meanwhile, resistor R4 and transistor Q3 form the enable control circuit for transistor Q1, which controls the output voltage VOUT of the microcontroller unit and turns it off.

[0038] Zener diode DZ1 is an interface voltage protection device that protects against voltage pulses and ESD damage to external interfaces.

[0039] Resistors R7 and R8 form a voltage divider acquisition circuit for the output voltage. The acquired output voltage is fed back to the microcontroller unit for software processing and judgment. The software can achieve effective control and protection for various states through algorithms.

[0040] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A voltage output structure with current limiting protection, characterized in that, include: The input voltage VIN is connected to the internal regulated power supply. The output voltage VOUT is connected to an external load module. The voltage output structure is connected to the input voltage VIN and the output voltage VOUT. The voltage output structure is equipped with a sampling resistor R1, a transistor Q1 and a transistor Q2. The sampling resistor R1 is connected to the transistor Q1, and the transistor Q2 is connected in parallel with the sampling resistor R1. The voltage output structure of the microcontroller unit is fed back to the microcontroller unit, and the microcontroller unit enables the voltage output structure. A diode D1 is connected in series between the input voltage VIN and the output voltage VOUT, and a Zener diode DZ1 is provided between the diode D1 and the output voltage VOUT.

2. The voltage output structure with current limiting protection according to claim 1, characterized in that, The sampling resistor R1 is connected to the input voltage VIN.

3. The voltage output structure with current limiting protection according to claim 1, characterized in that, Transistor Q1, transistor Q2, and sampling resistor R1 form a current-limiting protection output circuit.

4. A voltage output structure with current limiting protection according to claim 1, characterized in that, A transistor Q3, resistor R5, and resistor R6 are connected in series with the sampling resistor R1, forming a feedback control enable circuit.

5. A voltage output structure with current limiting protection according to claim 1, characterized in that, Resistor R4 and transistor Q3 form the enable control circuit for transistor Q1.

6. A voltage output structure with current limiting protection according to claim 1, characterized in that, The base of transistor Q1 is connected to capacitor C1, and resistors R7 and R8 are connected in parallel across capacitor C1.

7. A voltage output structure with current limiting protection according to claim 1, characterized in that, Resistors R7 and R8 form a voltage divider acquisition circuit for the output voltage.

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