Starting voltage conversion circuit of power supply control chip

Abstract

The utility model discloses a starting voltage conversion circuit of a power supply control chip. The starting voltage conversion circuit comprises an input voltage sampling circuit, a starting voltage conversion circuit and a power supply control chip U9, the input voltage sampling circuit is composed of a resistor R142, a resistor R128, a resistor R139, a resistor R129, a resistor R140 and a capacitor C29. The starting voltage conversion circuit is composed of a resistor R141, a switch tube, a diode D7, a resistor R136 and a capacitor C71. According to the utility model, the circuit structure is simple and reliable, and the conversion from the input voltage to the starting voltage required by the power supply control chip can be realized with fewer devices.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply technical field, specifically relates to a power control chip starting voltage conversion circuit. BACKGROUND

[0002] In the application environment of DC / DC power supply with medium and high input voltage, the design and implementation of power supply system face a series of unique challenges. In the DC / DC power supply system, the range of input voltage can be very wide, from low voltage to medium and high voltage, but the supply voltage of power supply control circuit or conversion chip usually has a relatively fixed range. When the input voltage is higher than this fixed range, the phenomenon of supply incompatibility will occur, which will lead to the decline of power conversion efficiency, the damage of system stability, and even the damage of chip.

[0003] In order to solve this problem, the traditional method is to add a part of pre-stabilization circuit at the end of chip or control circuit. The function of pre-stabilization circuit is to reduce the input voltage to a voltage range suitable for the work of power supply control circuit or conversion chip. In this way, even if the input voltage is very high, it can also be stabilized at a lower voltage level that the chip can accept through the pre-stabilization circuit. However, this method also has some obvious disadvantages:

[0004] 1. Complex circuit: pre-stabilization circuit usually contains multiple components and complex control circuit, which makes the design and implementation of the whole power supply system more difficult.

[0005] 2. Large volume: due to the need to accommodate multiple components and control circuit, pre-stabilization circuit often occupies a large space. This is a great challenge for small volume power supply, because small volume power supply needs to reduce the number and volume of components as much as possible.

[0006] 3. High cost: the complexity and volume of pre-stabilization circuit increase its manufacturing cost, thus increasing the cost of the whole power supply system. INVENTION CONTENT

[0007] In order to overcome the problems of complex circuit, large volume and high cost in providing starting voltage for power control chip with medium and high input voltage in the prior art, the utility model provides a power control chip starting voltage conversion circuit.

[0008] The technical scheme of the utility model is as follows:

[0009] A power control chip starting voltage conversion circuit, comprising an input voltage sampling circuit, a starting machine voltage conversion circuit and a power control chip U9.

[0010] The input voltage sampling circuit comprises a resistor R142, a resistor R128, a resistor R139, a resistor R129, a resistor R140, and a capacitor C29, one end of the resistor R142 is connected with an input voltage, the other end of the resistor R142 is connected with one end of the resistor R129, one end of the resistor R140, one end of the capacitor C29 and the seventh pin of the power control chip U9 through the resistor R128 and the resistor R139 respectively, the other end of the resistor R129, the other end of the resistor R140 and the other end of the capacitor C29 are grounded.

[0011] The starting voltage conversion circuit comprises a resistor R141, a switch tube, a diode D7, a resistor R136 and a capacitor C71, one end of the resistor R141 is connected with an input voltage, the other end of the resistor R141 is connected with the first end of the switch tube, the second end of the switch tube is connected with one end of the resistor R142, one end of the resistor R128 and the negative electrode of the diode D7 respectively, the third end of the diode D7 is connected with the positive electrode of the diode D7 and one end of the resistor R136 respectively, the other end of the resistor R136 is connected with one end of the capacitor C71 and the first pin of the power control chip U9 respectively, the other end of the capacitor C71 is grounded.

[0012] As a preferred scheme of the utility model, the switch tube is a triode Q3, the collector of the triode Q3 is connected with the other end of the resistor R141, the base of the triode Q3 is connected with one end of the resistor R142, one end of the resistor R128 and the negative electrode of the diode D7 respectively, the emitter of the triode Q3 is connected with the positive electrode of the diode D7 and one end of the resistor R136 respectively.

[0013] As a preferred scheme of the utility model, the triode Q3 is an NPN type triode.

[0014] As a preferred scheme of the utility model, the switch tube is a MOS tube Q13, the drain of the MOS tube Q13 is connected with the other end of the resistor R141, the gate of the MOS tube Q13 is connected with one end of the resistor R142, one end of the resistor R128 and the negative electrode of the diode D7 respectively, the source of the MOS tube Q13 is connected with the positive electrode of the diode D7 and one end of the resistor R136 respectively.

[0015] As a preferred scheme of the utility model, the MOS tube Q13 is an NMOS tube with a bidirectional breakdown diode and a damping diode.

[0016] As a preferred scheme of the utility model, still include resistance R8, one end of resistance R8 is connected with one end of resistance R129, one end of resistance R140, one end of capacitor C29 respectively, the other end of resistance R8 is connected with the 7th pin of power control chip U9.

[0017] As a preferred scheme of the utility model, still include capacitor C6, one end of capacitor C6 is connected with the 4th pin of power control chip U9 and power supply voltage respectively, the other end of capacitor C6 is grounded.

[0018] As a preferred scheme of the utility model, still include capacitor C4, one end of capacitor C4 is connected with the 8th pin of power control chip U9, the other end of capacitor C4 is grounded.

[0019] As a preferred scheme of the utility model, still include resistance R18, resistance R17, one end of resistance R18 is connected with power supply voltage, the other end of one end of resistance R18 is connected with the 2nd pin of power control chip U9 and one end of resistance R17 respectively, the other end of resistance R17 is connected with the 6th pin of power control chip U9 and ground respectively.

[0020] As a preferred scheme of the utility model, still include capacitor C3, resistance R10, resistance R9, capacitor C2, one end of capacitor C3 is connected with the 3rd pin of power control chip U9, the other end of capacitor C3 is connected with one end of resistance R9, one end of capacitor C2 and ground respectively after passing through resistance R10, the other end of resistance R9 is connected with the 9th pin of power control chip U9, the other end of capacitor C2 is connected with the 10th pin of power control chip U9.

[0021] Compared with the prior art, the utility model has the advantages of:

[0022] 1, the circuit is composed of simple resistance, capacitor, switch tube and diode etc. device, has realized the conversion of input voltage to the required starting voltage of power control chip, has simplified the complex device layout and connection mode in traditional circuit design significantly, and stability and reliability are high;

[0023] 2, the circuit adopts less device, and these devices are common, small, easy to purchase and relatively low price electronic device, effectively reduces the volume and production cost of whole circuit, has greater practical significance to high density power supply;

[0024] 3, the circuit structure is simple, and the device quantity is few, therefore, when the fault appears, is easier to locate the problem and carries out the repair, reduces the maintenance cost, improves the maintainability of equipment. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 Circuit diagram of the power control chip starting voltage conversion circuit in an embodiment of the present application;

[0027] Figure 2 Circuit diagram of the power control chip starting voltage conversion circuit in another embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects of the present application more clearly understood, the present application will be further described in detail below with reference to the drawings and embodiments. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, it is declared that the following described embodiments are only used to explain the present application, and do not limit the present application.

[0029] It should be noted that the terms "mounting", "setting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two devices or the interaction relationship between two devices, unless otherwise explicitly limited. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the product of the application is used, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship commonly placed when the product of the application is used, which is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or component must have a particular orientation, structure and operation, so it cannot be understood as a limitation on the present application. The terms "first", "second" are only used for the purpose of convenience, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "multiple" is two or more, unless otherwise explicitly limited. The meaning of "several" is one or more, unless otherwise explicitly limited.

[0030] Please refer to Figure 1The embodiment provides a power control chip starting voltage conversion circuit, which comprises an input voltage sampling circuit 1, a starting machine voltage conversion circuit 2 and a power control chip U9.

[0031] The input voltage sampling circuit 1 comprises resistors R142, R128, R139, R129, R140 and a capacitor C29, one end of the resistor R142 is connected with an input voltage VIN+, the other end of the resistor R142 is connected with one end of the resistor R129, one end of the resistor R140 and one end of the capacitor C29 and the seventh pin of the power control chip U9 through the resistors R128 and R139, respectively, and the other end of the resistor R129, the other end of the resistor R140 and the other end of the capacitor C29 are grounded.

[0032] The starting machine voltage conversion circuit 2 comprises a resistor R141, a switch tube, a diode D7, a resistor R136 and a capacitor C71, one end of the resistor R141 is connected with the input voltage VIN+, the other end of the resistor R141 is connected with the first end of the switch tube, the second end of the switch tube is connected with one end of the resistor R142, one end of the resistor R128 and the negative electrode of the diode D7, respectively, the third end of the diode D7 is connected with the positive electrode of the diode D7 and one end of the resistor R136, respectively, the other end of the resistor R136 is connected with one end of the capacitor C71 and the first pin of the power control chip U9, and the other end of the capacitor C71 is grounded.

[0033] Working principle: the input voltage sampling circuit 1 divides the input voltage into a lower voltage through sampling resistance division, and supplies the control end of the switch tube of the starting machine voltage conversion circuit 2, and then the input voltage VIN+ supplied to the power control chip U9 is reduced in proportion through the voltage drop of the switch tube, so that the power supply requirement of the power control chip is met.

[0034] The power control chip starting voltage conversion circuit of the embodiment is composed of simple resistors, capacitors, switch tubes and diodes, realizes conversion of the input voltage into the required starting voltage of the power control chip, significantly simplifies the complex device layout and connection mode in the traditional circuit design, and is high in stability and reliability; since fewer devices are adopted, and these devices are common, small in size, easy to purchase and relatively low in price, the volume and production cost of the whole circuit are effectively reduced, and the power control chip starting voltage conversion circuit has great practical significance for high-density power supply; in addition, since the circuit structure is simple and the number of devices is small, it is easier to locate problems and repair when faults occur, maintenance cost is reduced, and the maintainability of the equipment is improved.

[0035] Please refer to Figure 1In one embodiment, the switch tube is a triode Q3. Specifically, the collector of the triode Q3 is connected to the other end of the resistor R141, the base of the triode Q3 is connected to one end of the resistor R142, one end of the resistor R128 and the negative electrode of the diode D7 respectively, and the emitter of the triode Q3 is connected to the positive electrode of the diode D7 and one end of the resistor R136 respectively. In operation, the input voltage sampling circuit 1 divides the input voltage into a lower voltage through the sampling resistor to supply power to the base of the triode Q3. When the base receives sufficient voltage, the triode Q3 is turned on to allow current to flow from the collector to the emitter. In this process, the triode Q3 acts as a voltage regulator to reduce the input voltage VIN+ by a certain proportion to meet the power supply requirements of the power control chip U9.

[0036] In one specific embodiment, the triode Q3 is an NPN triode. The NPN triode can work in a wide voltage range, which makes it suitable for various input voltage situations. In this circuit, it can handle high-voltage input and convert it into the required starting voltage for the power control chip.

[0037] Please refer to Figure 2 In another embodiment, the switch tube is a MOS tube Q13. Specifically, the drain of the MOS tube Q13 is connected to the other end of the resistor R141, the gate of the MOS tube Q13 is connected to one end of the resistor R142, one end of the resistor R128 and the negative electrode of the diode D7 respectively, and the source of the MOS tube Q13 is connected to the positive electrode of the diode D7 and one end of the resistor R136 respectively. In operation, the input voltage sampling circuit 1 divides the input voltage into a lower voltage through the sampling resistor to supply power to the gate of the MOS tube Q13. When the gate receives sufficient voltage, the MOS tube Q13 is turned on to allow current to flow from the drain to the source. In this process, the MOS tube Q13 acts as a voltage regulator to reduce the input voltage VIN+ by a certain proportion to meet the power supply requirements of the power control chip U9.

[0038] In one specific embodiment, MOS tube Q13 is an NMOS tube with a bidirectional breakdown diode and a damping diode. The bidirectional breakdown diode can be turned on when the reverse voltage exceeds its breakdown voltage, thereby protecting the MOS tube from reverse voltage damage. The damping diode is used to eliminate the oscillation signal of the MOS tube gate. During the switching process of the MOS tube, due to the existence of parasitic inductance and parasitic capacitance, oscillation signals may be generated, and the damping diode can absorb these oscillation signals, thereby ensuring the stable operation of the circuit. The NMOS tube can work in a wide voltage range, adapting to different input voltage requirements. Therefore, using an NMOS tube with a bidirectional breakdown diode and a damping diode as a switching tube not only improves the reliability and stability of the circuit, but also provides more efficient voltage conversion and a wider voltage range; at the same time, due to the characteristics of low on-resistance and high input impedance of the MOS tube, this also helps to reduce the power consumption of the circuit and improve the power supply efficiency of the power control chip.

[0039] Please refer to Figure 1 In one embodiment, the power control chip startup voltage conversion circuit further includes a resistor R8, one end of the resistor R8 is connected to one end of the resistor R129, one end of the resistor R140, and one end of the capacitor C29, respectively, and the other end of the resistor R8 is connected to the 7th pin of the power control chip U9. The resistor R8 plays a role of current limiting and voltage dividing in the circuit, which limits the current from the input voltage sampling circuit 1 to the 7th pin of the power control chip U9, thereby protecting the power control chip from excessive current damage.

[0040] Please refer to Figure 1 In one embodiment, the power control chip startup voltage conversion circuit further includes a capacitor C6 and a capacitor C4, one end of the capacitor C6 is connected to the 4th pin of the power control chip U9 and the supply voltage VCC, respectively, one end of the capacitor C4 is connected to the 8th pin of the power control chip U9, and the other end of the capacitor C6 and the other end of the capacitor C4 are grounded. The capacitor C6 acts as a filter capacitor, which can smooth the fluctuations in the supply voltage VCC, reduce voltage ripple, and provide a stable and clean power supply environment for the power control chip U9. The capacitor C4 acts as a bypass capacitor, which can stabilize the voltage on the 8th pin of the power control chip U9, preventing unstable operation of the chip due to voltage fluctuations.

[0041] Please refer to Figure 1In one embodiment, the power supply control chip starting voltage conversion circuit further comprises a resistor R18, a resistor R17, a capacitor C3, a resistor R10, a resistor R9, a capacitor C2, one end of the resistor R18 is connected with the power supply voltage VCC, the other end of the one end of the resistor R18 is connected with the second pin of the power supply control chip U9 and one end of the resistor R17 respectively, the other end of the resistor R17 is connected with the sixth pin of the power supply control chip U9 and the ground respectively, one end of the capacitor C3 is connected with the third pin of the power supply control chip U9, the other end of the capacitor C3 is connected with one end of the resistor R9, one end of the capacitor C2 and the ground through the resistor R10 respectively, the other end of the resistor R9 is connected with the ninth pin of the power supply control chip U9, the other end of the capacitor C2 is connected with the tenth pin of the power supply control chip U9. The resistor R18, the resistor R17, the capacitor C3, the resistor R10, the resistor R9 and the capacitor C2 constitute the peripheral circuit of the power supply control chip U9. Among them, R18 and R17 constitute a voltage dividing circuit to reduce the power supply voltage VCC to the acceptable range of the second pin of the power supply control chip U9 to ensure the normal work of the chip; C3 is used as a decoupling capacitor to help reduce the power supply noise on the third pin of the power supply control chip U9; and the resistor R10, the resistor R9 and the capacitor C2 constitute an RC filter network to smooth the feedback signal on the ninth pin of the power supply control chip U9 and stabilize the voltage on the tenth pin of the power supply control chip U9.

[0042] It should be understood that the above description can be improved or changed by those skilled in the art, and all these improvements and changes shall fall within the protection scope of the appended claims of the present application.

[0043] The above describes the present application with reference to the drawings, obviously, the implementation of the present application is not limited to the above manner, as long as various improvements or direct applications of the present application are made, or the concept and technical scheme of the present application are applied to other occasions without improvement, all of which are within the protection scope of the present application.

Claims

1. A power control chip start-up voltage conversion circuit, characterized by, The input voltage sampling circuit comprises a resistor R142, a resistor R128, a resistor R139, a resistor R129, a resistor R140 and a capacitor C29. The input voltage sampling circuit comprises a resistor R142, a resistor R128, a resistor R139, a resistor R129, a resistor R140 and a capacitor C29. The switch tube is a MOS tube Q13, the drain of the MOS tube Q13 is connected with the other end of the resistor R141, the gate of the MOS tube Q13 is connected with the one end of the resistor R142, the one end of the resistor R128 and the negative electrode of the diode D7 respectively, and the source of the MOS tube Q13 is connected with the positive electrode of the diode D7 and the one end of the resistor R136 respectively.

2. The power control chip start-up voltage conversion circuit of claim 1, wherein, The switch tube is a MOS tube Q13, the drain of the MOS tube Q13 is connected with the other end of the resistor R141, the gate of the MOS tube Q13 is connected with the one end of the resistor R142, the one end of the resistor R128 and the negative electrode of the diode D7 respectively, and the source of the MOS tube Q13 is connected with the positive electrode of the diode D7 and the one end of the resistor R136 respectively.

3. The power control chip start-up voltage conversion circuit of claim 2, wherein, The MOS tube Q13 is an NMOS tube with a bidirectional breakdown diode and a damping diode.

4. The power control chip start-up voltage conversion circuit of claim 1, wherein, The resistor R8 is connected with the one end of the resistor R129, the one end of the resistor R140 and the one end of the capacitor C29 respectively, and the other end of the resistor R8 is connected with the seventh pin of the power supply control chip U9.

5. The power control chip start-up voltage conversion circuit of claim 4, wherein, The capacitor C6 is connected with the fourth pin of the power supply control chip U9 and the power supply voltage respectively, and the other end of the capacitor C6 is grounded.

6. The power control chip start-up voltage conversion circuit of claim 1, wherein, The capacitor C4 is connected with the eighth pin of the power supply control chip U9, and the other end of the capacitor C4 is grounded.

7. The power control chip start-up voltage conversion circuit of claim 1, wherein, ​ 8. The power control chip start-up voltage conversion circuit of claim 1, wherein, ​ 9. The power control chip start-up voltage conversion circuit of claim 1, wherein, Also include resistance R18, resistance R17, one end of the resistance R18 is connected with the power supply voltage, the other end of one end of the resistance R18 is connected with the 2nd pin of the power supply control chip U9 and one end of the resistance R17 respectively, the other end of the resistance R17 is connected with the 6th pin of the power supply control chip U9 and ground respectively.

10. The power control chip start-up voltage conversion circuit of claim 1, wherein, Also include capacitor C3, resistance R10, resistance R9, capacitor C2, one end of the capacitor C3 is connected with the 3rd pin of the power supply control chip U9, the other end of the capacitor C3 is connected with one end of the resistance R9, one end of the capacitor C2 and ground through the resistance R10 respectively, the other end of the resistance R9 is connected with the 9th pin of the power supply control chip U9, the other end of the capacitor C2 is connected with the 10th pin of the power supply control chip U9.

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