Power conversion circuit, linear voltage regulator and electronic product

Abstract

The invention provides a power conversion circuit, a linear voltage regulator and an electronic product, and the circuit comprises a high-voltage input level conversion unit which generates a clamping voltage, generates a low-voltage output power supply when a high-voltage input power supply is larger than a set voltage, and is turned off when the high-voltage input power supply is smaller than or equal to the set voltage; the current comparison unit is used for receiving the clamping voltage, comparing the detection current of the high-voltage input power supply with the reference current and generating a comparison result; and the level conversion unit generates a corresponding output signal based on the comparison result, takes the high-voltage input power supply as a low-voltage output power supply when the high-voltage input power supply is smaller than or equal to the set voltage, and is switched off when the high-voltage input power supply is larger than the set voltage. The power conversion circuit, the linear voltage regulator and the electronic product are simple in structure and can adaptively convert the power supply; under different input voltages, the low-voltage output power supply is controlled through the two level conversion circuits, so that a wider input voltage range is obtained.

Description

Technical Field

[0001] The present invention relates to the field of power supply, and in particular to a power supply conversion circuit, a linear voltage regulator and an electronic product. Background Art

[0002] As a signal that provides energy for each functional module, the stability of the power supply is particularly important for the normal operation of subsequent functional modules. The existing power supply module is connected to an external power supply, and performs DC conversion based on the external power supply to obtain the working voltage required by each functional module in the circuit. Once the external power supply drops significantly, it will lead to insufficient power, and the subsequent functional modules cannot work normally, which will have a serious impact on the stability of the circuit.

[0003] Therefore, how to broaden the range of input power and solve the problem of unstable power supply of internal devices has become one of the problems that technical personnel in this field need to solve urgently.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present invention and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the present invention. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a power conversion circuit, a linear voltage regulator and an electronic product, which are used to solve the internal power supply problem caused by the narrow input power range in the prior art.

[0006] To achieve the above-mentioned object and other related objects, the present invention provides a power conversion circuit, which at least includes:

[0007] High voltage input level conversion unit, current comparison unit and level conversion unit;

[0008] The high-voltage input level conversion unit receives a high-voltage input power supply, generates a clamping voltage, and generates a low-voltage output power supply when the high-voltage input power supply is greater than a set voltage, and the high-voltage input level conversion unit is turned off when the high-voltage input power supply is less than or equal to the set voltage;

[0009] The current comparison unit receives the clamping voltage, compares the detection current of the high voltage input power supply with a reference current, and generates a comparison result;

[0010] The level conversion unit is connected to the output end of the current comparison unit, and generates a corresponding output signal based on the comparison result. When the high-voltage input power supply is less than or equal to the set voltage, the high-voltage input power supply is used as the low-voltage output power supply. When the high-voltage input power supply is greater than the set voltage, the level conversion unit is turned off.

[0011] Optionally, the high-voltage input level conversion unit includes a current limiting module, a clamping module, a first power tube and a capacitor;

[0012] One end of the current limiting module is connected to the high voltage input power supply, and the other end is grounded via the clamping module; the connection node between the current limiting module and the clamping module outputs the clamping voltage;

[0013] One end of the first power tube is connected to the high-voltage input power supply, the other end serves as the output end of the high-voltage input level conversion unit and is grounded via the capacitor, and the control end receives the clamping voltage.

[0014] More optionally, the current limiting module includes a first resistor, and the clamping module includes a first diode; one end of the first resistor is connected to the high-voltage input power supply, and the other end serves as the output end of the current limiting module and is connected to the cathode of the first diode; the anode of the first diode is grounded.

[0015] More optionally, the first power tube is an NMOS tube.

[0016] Optionally, the detection current is positively correlated or negatively correlated with the voltage of the high-voltage input power supply.

[0017] More optionally, the current comparison unit includes a PMOS current mirror module, a second diode, a first NMOS transistor, a second NMOS transistor, a first current source and a second current source;

[0018] One end of the first current source is grounded, and the other end is connected to the source of the first NMOS tube; the gate of the first NMOS tube receives the clamping voltage, and the drain is connected to the anode of the second diode; the cathode of the second diode is connected to the first end of the PMOS current mirror module; the power supply end of the PMOS current mirror module is connected to the high-voltage input power supply, and the second end serves as the output end of the current comparison unit and is connected to the drain of the second NMOS tube; the gate of the second NMOS tube receives the clamping voltage, and the drain is grounded via the second current source.

[0019] Optionally, the level conversion unit includes a second power tube, a third diode and a fourth diode;

[0020] One end of the second power tube is connected to the high-voltage input power supply, the other end serves as the output end of the level conversion unit and is connected to the cathode of the third diode, and the control end is connected to the output end of the current comparison unit; the anode of the third diode is grounded; the cathode of the fourth diode is connected to the high-voltage input power supply, and the anode is connected to the gate of the second power tube.

[0021] More optionally, the second power tube is a PMOS tube.

[0022] More optionally, the power conversion circuit is prepared using a BCD process.

[0023] To achieve the above-mentioned object and other related objects, the present invention further provides a linear voltage regulator, which at least comprises: a voltage stabilization circuit and the above-mentioned power conversion circuit;

[0024] The power conversion circuit is connected to the voltage stabilizing circuit to provide an operating voltage for the voltage stabilizing circuit.

[0025] In order to achieve the above-mentioned object and other related objects, the present invention further provides an electronic product, which at least includes: the above-mentioned power conversion circuit.

[0026] As described above, the power conversion circuit, linear voltage regulator and electronic product of the present invention have the following beneficial effects:

[0027] 1. The power conversion circuit, linear voltage regulator and electronic product circuit of the present invention have simple structures and can adaptively convert power.

[0028] 2. The power conversion circuit, linear voltage regulator and electronic product circuit of the present invention can generate a current related to the high-voltage input power supply through a second diode, and raise the internal low-voltage output power supply when the high-voltage input power supply is low by comparing with the reference current.

[0029] 3. The power conversion circuit, linear voltage regulator and electronic product circuit of the present invention control the low-voltage output power supply through two level conversion circuits under different input voltages to obtain a wider input voltage range, solve the problem of power supply of internal devices when the input power is low, and improve customer experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Shown is a principle block diagram of the power conversion circuit of the present invention.

[0031] Figure 2 Shown is a schematic structural diagram of the power conversion circuit of the present invention.

[0032] Figure 3 Shown is a schematic diagram of waveforms of key nodes of the power conversion circuit of the present invention.

[0033] Figure 4 It is a schematic structural diagram of the linear regulator of the present invention.

[0034] Component number description

[0035] 1 Power conversion circuit

[0036] 11 High voltage input level conversion unit

[0037] 111 Current Limiting Module

[0038] 112 Clamp Module

[0039] 12 Current comparison unit

[0040] 121 PMOS current mirror module

[0041] 122 Hysteresis module

[0042] 13 Level conversion unit

[0043] 2 Voltage stabilization circuit DETAILED DESCRIPTION

[0044] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0045] See also Figure 1 to Figure 4 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0046] like Figure 1 As shown, the present invention provides a power conversion circuit 1, and the power conversion circuit 1 includes:

[0047] The high voltage input level conversion unit 11 , the current comparison unit 12 and the level conversion unit 13 .

[0048] like Figure 1As shown, the high-voltage input level conversion unit 11 receives a high-voltage input power supply VDDH, generates a clamping voltage, and generates a low-voltage output power supply VDDL when the high-voltage input power supply VDDH is greater than a set voltage. When the high-voltage input power supply VDDH is less than or equal to the set voltage, the high-voltage input level conversion unit 11 is turned off.

[0049] Specifically, the set voltage can be set according to actual needs. In the present embodiment, the set voltage is set to 5V, that is, when the high-voltage input power supply VDDH is greater than 5V, the low-voltage output power supply VDDL is obtained by voltage reduction (the voltage value of VDDL is less than the voltage value of the high-voltage input power supply VDDH); when the high-voltage input power supply VDDH drops to less than or equal to 5V, the high-voltage input level conversion unit 11 is turned off and no output power is provided.

[0050] Specifically, in this embodiment, the high-voltage input level conversion unit 11 includes a current limiting module 111, a clamping module 112, a first power tube M1 and a capacitor C1. One end of the current limiting module 111 is connected to the high-voltage input power supply VDDH, and the other end is grounded GND via the clamping module 112, and the connection node between the current limiting module and the clamping module outputs the clamping voltage V_clamp; as an example, the current limiting module 111 includes a first resistor R1, and the clamping module 112 includes a first diode D1, one end of the first resistor R1 is connected to the high-voltage input power supply VDDH, the other end of the first resistor R1 is connected to the cathode of the first diode D1, and the anode of the first diode D1 is grounded GND. One end of the first power tube M1 is connected to the high-voltage input power supply VDDH, and the other end serves as the output end of the high-voltage input level conversion unit 11 and is grounded GND via the capacitor C1, and the control end receives the clamping voltage V_clamp; as an example, the first power tube M1 is an NMOS tube, the drain is connected to the high-voltage input power supply VDDH, the gate is connected to the clamping voltage V_clamp, and the source is connected to the upper plate of the capacitor C1. When the high-voltage input power supply VDDH is greater than the set voltage, the clamping voltage V_clamp drives the first power tube M1 to turn on and generate a corresponding current to charge the capacitor C1, thereby obtaining a low-voltage output power supply VDDL; when the high-voltage input power supply VDDH is less than or equal to the set voltage, the clamping voltage V_clamp turns off the first power tube M1 and does not provide a charging current.

[0051] It should be noted that in actual use, the specific circuit structure of the high voltage input level conversion unit 11 and the switch relationship between the clamping voltage V_clamp and the first power tube M1 can be set as needed, as long as the logical relationship of the present invention can be realized.

[0052] like Figure 1 As shown, the current comparison unit 12 receives the clamping voltage V_clamp, compares the detection current of the high voltage input power source VDDH with a reference current, and generates a comparison result VDDH_L.

[0053] Specifically, the current comparison unit 12 generates a corresponding detection current I3 based on the high-voltage input power supply VDDH, and compares the detection current I3 with the reference current, wherein the detection current I3 is positively correlated or negatively correlated with the voltage of the high-voltage input power supply VDDH, and is set as needed. As an example, the detection current I3 is proportional to the voltage of the high-voltage input power supply VDDH. In this embodiment, the current comparison unit 12 includes a PMOS current mirror module 121, a second diode D2, a first NMOS tube MN1, a second NMOS tube MN2, a first current source I1, and a second current source I2.

[0054] More specifically, one end of the first current source I1 is grounded GND, and the other end is connected to the source of the first NMOS transistor MN1. The gate of the first NMOS transistor MN1 receives the clamping voltage V_clamp, and the drain is connected to the anode of the second diode D2. The cathode of the second diode D2 is connected to the first end of the PMOS current mirror module 121. In this example, the second diode D2 is a low-voltage Zener diode. In actual use, the second diode D2 can use other devices with a turn-on voltage or a breakdown voltage, including but not limited to a diode-connected MOS device. The power supply end of the PMOS current mirror module 121 is connected to the high-voltage input power supply VDDH, and the second end is used as the output end of the current comparison unit 12 and is connected to the drain of the second NMOS tube MN2; in this embodiment, the PMOS current mirror module 121 includes a third PMOS tube MP3 and a fourth PMOS tube MP4, the sources of the third PMOS tube MP3 and the fourth PMOS tube MP4 are connected to the high-voltage input power supply VDDH, the drain and the gate of the third PMOS tube MP3 are connected together as the first end of the PMOS current mirror module 121, the gate of the fourth PMOS tube MP4 is connected to the gate of the third PMOS tube MP3, and the drain of the fourth PMOS tube MP4 is used as the second end of the PMOS current mirror module 121. The gate of the second NMOS tube receives the clamping voltage V_clamp, and the drain is grounded GND via the second current source I2. The high-voltage input power source VDDH generates a corresponding current in the path where the second diode D2 is located and obtains the detection current I3 through the mirror image of the PMOS current mirror module 121. The detection current I3 is compared with the reference current provided by the second current source I2 to generate the comparison result VDDH_L. When VDDH is less than or equal to VGS(MP3)+VZ(D2), the third PMOS tube MP3 is turned off, the detection current I3 is less than or equal to the reference current I2, and the comparison result VDDH_L is pulled low. When VDDH is greater than VGS(MP3)+VZ(D2), the third PMOS tube MP3 is turned on, the detection current I3 is greater than the reference current I2, and the comparison result VDDH_L is pulled high. Wherein, VGS(MP3) is the gate-source voltage of the third PMOS tube MP3, and VZ(D2) is the breakdown voltage of the second diode D2.

[0055] It should be noted that the specific relationship between the reference current and the preset voltage can be configured according to the specific circuit structure and device parameters, and it is sufficient to determine the magnitude relationship between the high-voltage input power supply VDDH and the preset voltage, which will not be elaborated here.

[0056] Specifically, as another implementation of the present invention, the current comparison unit 12 further includes a hysteresis module 122, and the hysteresis module 122 includes a first PMOS tube MP1 and a second PMOS tube MP2. The source of the first PMOS tube MP1 is connected to the high-voltage input power supply VDDH, the gate is connected to the output end of the current comparison unit 12 (i.e., receiving the comparison result VDDH_L), and the drain is connected to the source of the second PMOS tube MP2; the gate and drain of the second PMOS tube MP2 are connected to the cathode of the second diode D2. In actual use, any circuit structure that can realize the hysteresis function is applicable to the present invention, and is not limited to this embodiment.

[0057] like Figure 1 As shown, the level conversion unit 13 is connected to the output end of the current comparison unit 12, and generates a corresponding output signal based on the comparison result VDDH_L. When the high-voltage input power supply VDDH is less than or equal to the set voltage, the high-voltage input power supply VDDH is output as the output power supply VDDL; when the high-voltage input power supply VDDH is greater than the set voltage, the level conversion unit 13 is turned off.

[0058] Specifically, in this embodiment, the level conversion unit 13 includes a second power tube M2, a third diode D3 and a fourth diode D4. One end of the second power tube M2 is connected to the high-voltage input power supply VDDH, the other end is used as the output end of the level conversion unit 13 and connected to the cathode of the third diode D2, and the control end is connected to the output end of the current comparison unit 12 (obtaining the comparison result VDDH_L); the anode of the third diode D2 is grounded GND; the cathode of the fourth diode D4 is connected to the high-voltage input power supply VDDH, and the anode is connected to the gate of the second power tube M2. As an example, the second power tube M2 is a PMOS tube, a source is connected to the high-voltage input power supply VDDH, a gate is connected to the output end of the current comparison unit 12, and a drain is connected to the cathode of the third diode D3. When the high-voltage input power supply VDDH is less than or equal to the set voltage, the comparison result VDDH_L (low level) controls the second power tube M2 to turn on and drives the second power tube M2 to generate a corresponding output current, thereby obtaining a low-voltage output power supply VDDL (at this time, VDDL≈VDDH, and the difference between the two is the voltage drop across the source and drain of the second power tube M2); when the high-voltage input power supply VDDH is greater than the set voltage, the comparison result VDDH_L (high level) controls the second power tube M2 to turn off and does not provide output current.

[0059] It should be noted that any circuit structure that can raise the output power voltage based on the high voltage input power when the high voltage input power is less than or equal to the preset voltage is applicable to the level conversion unit of the present invention, and is not limited to this embodiment.

[0060] As an implementation method of the present invention, the power conversion circuit 1 is prepared using a BCD (Bipolar-CMOS-DMOS) process; the BCD process refers to a manufacturing process that integrates analog, digital and power functions on the same chip, which can achieve highly integrated, small size, low power consumption and high performance circuit design.

[0061] like Figure 3 As shown, when the high-voltage input power supply VDDH is less than or equal to the set voltage, I4 is less than or equal to I2, the comparison result VDDH_L is a low level, and the level conversion unit 13 raises the low-voltage output power supply VDDL to VDDH. At this time, the first power tube M1 is turned off, and the low-voltage output power supply VDDL is provided by the level conversion unit 13; when the high-voltage input power supply VDDH is greater than the set voltage, a low-voltage output power supply VDDL is generated after conversion by the high-voltage input level conversion unit 11 to power subsequent low-voltage devices (as an example, the typical operating voltage of the internal low-voltage devices is set to 5V). At this time, I4 is greater than I2, the second power tube M2 is turned off, and the low-voltage output power supply VDDL is provided by the high-voltage input level conversion unit 11; thereby ensuring that the low-voltage output power supply VDDL is always sufficient to power subsequent circuits, avoiding the problem of low power supply affecting the power supply of subsequent circuits.

[0062] like Figure 4 As shown, the present invention further provides a linear voltage stabilizer, which includes: a voltage stabilizing circuit 2 and a power conversion circuit 1 of the present invention, wherein the power conversion circuit 1 is connected to the voltage stabilizing circuit 2 to provide a working voltage for the voltage stabilizing circuit 2.

[0063] Specifically, in the prior art, the working voltage of the voltage stabilizing circuit 2 is provided by an external power supply. Once the external power supply is low, the voltage stabilizing circuit 2 will not be able to provide sufficient voltage, thereby causing the subsequent circuit to be powered off. The voltage stabilizing circuit 2 of the present invention obtains power from the power conversion circuit 1. When the high-voltage input power supply VDDH is greater than the set voltage, the low-voltage output power supply VDDL is obtained from the high-voltage input level conversion unit 11; when the high-voltage input power supply VDDH is less than or equal to the set voltage, the low-voltage output power supply VDDL is obtained from the level conversion unit 13; in order to avoid the problem of too low power supply voltage, a stable power supply voltage V_LDO is generated.

[0064] The present invention also provides an electronic product, which at least includes: the power conversion circuit 1 of the present invention. The electronic product includes but is not limited to personal consumer electronic products (watches, mobile phones, computers, etc.) and medical monitoring electronic products, which are not described in detail here.

[0065] In summary, the present invention provides a power conversion circuit, a linear voltage regulator and an electronic product, comprising: a high-voltage input level conversion unit, a current comparison unit and a level conversion unit; the high-voltage input level conversion unit receives a high-voltage input power supply, generates a clamping voltage, and generates a low-voltage output power supply when the high-voltage input power supply is greater than a set voltage, and the high-voltage input level conversion unit is turned off when the high-voltage input power supply is less than or equal to the set voltage; the current comparison unit receives the clamping voltage, compares the detection current of the high-voltage input power supply with a reference current, and generates a comparison result; the level conversion unit is connected to the output end of the current comparison unit, generates a corresponding output signal based on the comparison result, uses the high-voltage input power supply as the low-voltage output power supply when the high-voltage input power supply is less than or equal to the set voltage, and turns off when the high-voltage input power supply is greater than the set voltage. The power conversion circuit, linear voltage regulator and electronic product of the present invention have simple structures and can adaptively convert power supplies; a current related to the high-voltage input power supply can be generated through a second diode, and the internal low-voltage output power supply can be raised when the high-voltage input power supply is low by comparing with the reference current; under different input voltages, the low-voltage output power supply is controlled by two level conversion circuits to obtain a wider input voltage range, solve the problem of internal device power supply when the input power supply is low, and improve customer experience. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A power conversion circuit, characterized in that: The power conversion circuit at least comprises: High voltage input level conversion unit, current comparison unit and level conversion unit; The high-voltage input level conversion unit receives a high-voltage input power supply, generates a clamping voltage, and generates a low-voltage output power supply when the high-voltage input power supply is greater than a set voltage, and the high-voltage input level conversion unit is turned off when the high-voltage input power supply is less than or equal to the set voltage; The current comparison unit receives the clamping voltage, compares the detection current of the high voltage input power supply with a reference current, and generates a comparison result; The level conversion unit is connected to the output end of the current comparison unit, and generates a corresponding output signal based on the comparison result. When the high-voltage input power supply is less than or equal to the set voltage, the high-voltage input power supply is used as the low-voltage output power supply. When the high-voltage input power supply is greater than the set voltage, the level conversion unit is turned off.

2. The power conversion circuit according to claim 1, characterized in that: The high-voltage input level conversion unit includes a current limiting module, a clamping module, a first power tube and a capacitor; One end of the current limiting module is connected to the high voltage input power supply, and the other end is grounded via the clamping module; the connection node between the current limiting module and the clamping module outputs the clamping voltage; One end of the first power tube is connected to the high-voltage input power supply, the other end serves as the output end of the high-voltage input level conversion unit and is grounded via the capacitor, and the control end receives the clamping voltage.

3. The power conversion circuit according to claim 2, characterized in that: The current limiting module includes a first resistor, and the clamping module includes a first diode; one end of the first resistor is connected to the high-voltage input power supply, and the other end serves as the output end of the current limiting module and is connected to the cathode of the first diode; the anode of the first diode is grounded.

4. The power conversion circuit according to claim 2, characterized in that: The first power tube is an NMOS tube.

5. The power conversion circuit according to claim 1, characterized in that: The detection current is positively correlated or negatively correlated with the voltage of the high-voltage input power supply.

6. The power conversion circuit according to claim 5, characterized in that: The current comparison unit includes a PMOS current mirror module, a second diode, a first NMOS transistor, a second NMOS transistor, a first current source and a second current source; One end of the first current source is grounded, and the other end is connected to the source of the first NMOS tube; the gate of the first NMOS tube receives the clamping voltage, and the drain is connected to the anode of the second diode; the cathode of the second diode is connected to the first end of the PMOS current mirror module; the power supply end of the PMOS current mirror module is connected to the high-voltage input power supply, and the second end serves as the output end of the current comparison unit and is connected to the drain of the second NMOS tube; the gate of the second NMOS tube receives the clamping voltage, and the drain is grounded via the second current source.

7. The power conversion circuit according to claim 6, characterized in that: The current comparison unit further includes a hysteresis module, which includes a first PMOS tube and a second PMOS tube; the source of the first PMOS tube is connected to the high-voltage input power supply, the gate is connected to the output end of the current comparison unit, and the drain is connected to the source of the second PMOS tube; The gate and drain of the second PMOS tube are connected to the cathode of the second diode.

8. The power conversion circuit according to claim 1, characterized in that: The level conversion unit includes a second power tube, a third diode and a fourth diode; One end of the second power tube is connected to the high-voltage input power supply, the other end serves as the output end of the level conversion unit and is connected to the cathode of the third diode, and the control end is connected to the output end of the current comparison unit; the anode of the third diode is grounded; the cathode of the fourth diode is connected to the high-voltage input power supply, and the anode is connected to the gate of the second power tube.

9. The power conversion circuit according to claim 8, characterized in that: The second power tube is a PMOS tube.

10. The power conversion circuit according to any one of claims 1 to 9, characterized in that: The power conversion circuit is prepared by using the BCD process.

11. A linear regulator, characterized in that: The linear voltage regulator at least comprises: a voltage stabilizing circuit and a power conversion circuit as claimed in any one of claims 1 to 10; The power conversion circuit is connected to the voltage stabilizing circuit to provide an operating voltage for the voltage stabilizing circuit.

12. An electronic product, characterized in that: The electronic product at least comprises: a power conversion circuit as described in any one of claims 1-10.

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