TWI832742B - Boost converter for suppressing magnetic saturation - Google Patents

Abstract

A boost converter for suppressing magnetic saturation includes a bridge rectifier, a boost inductor, a power switch element, an output stage circuit, and a detection and control circuit. The boost inductor is coupled to the bridge rectifier. An inductive current flows through the boost inductor. The power switch element selectively couples the boost inductor to a ground voltage according to a driving voltage. The output stage circuit is coupled to the boost inductor. The detection and control circuit monitors the boost inductor, and generates the driving voltage according to the inductive current. If the inductive current is relatively small, the driving voltage will be a PWM (Pulse Width Modulation) voltage with a constant switching frequency. If the inductive current is relatively large, the driving voltage will be a PFM (Pulse Frequency Modulation) voltage with a variable switching frequency.

Description

Boost converter that suppresses magnetic saturation

The present invention relates to a boost converter, and in particular to a boost converter capable of suppressing magnetic saturation.

In the field of boost converter design, the boost inductor is an indispensable component. However, each magnetic component has its hysteresis curve range for normal use. When the operating current of the boost converter is too large, the boost inductor may enter a magnetic saturation state, which will cause its magnetization characteristics to disappear and cause safety issues. In view of this, it is necessary to propose a new solution to overcome the difficulties faced by previous technologies.

In a preferred embodiment, the present invention proposes a boost converter that suppresses magnetic saturation, including: a bridge rectifier that generates a rectified potential based on a first input potential and a second input potential; a boost inductor, Receive the rectified potential, in which an inductor current flows through the boost inductor; a power switch selectively couples the boost inductor to a ground potential according to a driving potential; an output stage circuit couples is connected to the boost inductor and generates an output potential; and a detection and control circuit monitors the boost inductor and generates the driving potential according to the inductor current; if the inductor current is relatively small, then The driving potential is a pulse width modulation (PWM) potential with a fixed switching frequency; if the inductor current is relatively large, the driving potential is a pulse frequency with a variable switching frequency. Modulation (Pulse Frequency Modulation, PFM) potential.

In some embodiments, the boost inductor operates in a discontinuous current mode, a boundary current mode, or a continuous current mode.

In some embodiments, when the boost inductor operates in the discontinuous current mode or the boundary current mode, the driving potential is the pulse width modulation potential with the fixed switching frequency, and when the boost inductor operates in the discontinuous current mode or the boundary current mode, the driving potential is the pulse width modulation potential with the fixed switching frequency. When the inductor operates in the continuous current mode, the driving potential is the pulse frequency modulated potential with the variable switching frequency.

In some embodiments, the bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode of the first diode is coupled to a first input node to receive the first input potential, and the cathode of the first diode is coupled to a first node to output the rectified potential; a second diode has an anode and a cathode, wherein the second diode The anode is coupled to a second input node to receive the second input potential, and the cathode of the second diode is coupled to the first node; a third diode has an anode and a cathode , wherein the anode of the third diode is coupled to the ground potential, and the cathode of the third diode is coupled to the first input node; and a fourth diode having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground potential, and the cathode of the fourth diode is coupled to the second input node; wherein the boost inductor has a first One end and a second end, the first end of the boost inductor is coupled to the first node to receive the rectified potential, and the second end of the boost inductor is coupled to a second node.

In some embodiments, the power switch includes: a first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is used to receive the drive potential, the first terminal of the first transistor is coupled to the ground potential, and the second terminal of the first transistor is coupled to a third node.

In some embodiments, the output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the third node, and the fifth diode The cathode of the pole body is coupled to an output node to output the output potential; and an output capacitor has a first terminal and a second terminal, wherein the first terminal of the output capacitor is coupled to the output node , and the second terminal of the output capacitor is coupled to a fourth node.

In some embodiments, the detection and control circuit includes: a first resistor having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the second node , and the second end of the first resistor is coupled to the third node, and the inductor current further flows through the first resistor, so that a potential difference is formed between the second node and the third node. ; An averaging circuit that calculates an average value of the potential difference to generate an average potential; and a second resistor having a first end and a second end, wherein the first end of the second resistor is coupled is connected to the fourth node, and the second end of the second resistor is coupled to the ground potential, and one of the output currents flows through the second resistor, so that the second resistor can A sensing potential is provided at four nodes.

In some embodiments, the detection and control circuit further includes: a third resistor having a first terminal and a second terminal, wherein the first terminal of the third resistor is used to receive the average potential, The second terminal of the third resistor is coupled to a fifth node; and a second transistor has a control terminal, a first terminal, and a second terminal, wherein the second transistor The control terminal is coupled to the fifth node, the first terminal of the second transistor is coupled to the ground potential, and the second terminal of the second transistor is coupled to a sixth node.

In some embodiments, the detection and control circuit further includes: a fourth resistor having a first end and a second end, wherein the first end of the fourth resistor is used to receive the sensing potential. , and the second terminal of the fourth resistor is coupled to a seventh node; and a third transistor has a control terminal, a first terminal, and a second terminal, wherein the third transistor The control terminal is coupled to the seventh node, the first terminal of the third transistor is coupled to the sixth node, and the second terminal of the third transistor is coupled to an eighth node. node.

In some embodiments, the detection and control circuit further includes: a microcontroller generating a reference potential; and a comparator having a positive input terminal, a negative input terminal, and an output terminal, wherein the comparator The positive input terminal is used to receive the reference potential, the negative input terminal of the comparator is coupled to the eighth node, and the output terminal of the comparator is used to output a comparison potential; wherein the microcontroller The device further generates and determines the driving potential based on the comparison potential.

In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are listed below and described in detail with reference to the accompanying drawings.

Certain words are used in the specification and patent claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and the patent application do not use differences in names as a way to distinguish components, but differences in functions of components as a criterion for distinction. The words "include" and "include" mentioned throughout the specification and the scope of the patent application are open-ended terms, and therefore should be interpreted as "include but not limited to." The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem and achieve the basic technical effect within a certain error range. In addition, the word "coupling" in this specification includes any direct and indirect electrical connection means. Therefore, if a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device via other devices or connections. Two devices.

FIG. 1 is a schematic diagram of a boost converter 100 according to an embodiment of the present invention. For example, the boost converter 100 can be applied to desktop computers, notebook computers, or all-in-one computers. As shown in FIG. 1 , the boost converter 100 includes: a bridge rectifier 110 , a boost inductor LU, a power switch 120 , an output stage circuit 130 , and a detection and control circuit 150 . It should be noted that, although not shown in FIG. 1 , the boost converter 100 may further include other components, such as a voltage regulator or/and a negative feedback circuit.

The bridge rectifier 110 can generate a rectified potential VR according to a first input potential VIN1 and a second input potential VIN2, wherein one of the first input potential VIN1 and the second input potential VIN2 can have any frequency and any amplitude. AC voltage. For example, the frequency of the AC voltage can be about 50Hz or 60Hz, and the root mean square value of the AC voltage can be about 90V to 264V, but it is not limited thereto. The boost inductor LU can receive the rectified potential VR, and an inductor current IL can flow through the boost inductor LU. The power switch 120 can selectively couple the boost inductor LU to a ground potential VSS (eg, 0V) according to a driving potential VG. For example, if the driving potential VG is a high logic level (ie, logic “1”), the power switch 120 can couple the boost inductor LU to the ground potential VSS (ie, the power switch 120 can approximately in a short-circuit path); on the contrary, if the driving potential VG is a low logic level (that is, logic "0"), the power switch 120 will not couple the boost inductor LU to the ground potential VSS (that is, , the power switch 120 may be approximated as an open path). The output stage circuit 130 is coupled to the boost inductor LU and can generate an output potential VOUT. For example, the output potential VOUT can be a DC potential, and its potential level can be about 400V, but it is not limited thereto. The detection and control circuit 150 can monitor the boost inductor LU and generate the driving potential VG according to its inductor current IL. Roughly speaking, if the inductor current IL is relatively small (for example, an average value of the inductor current IL is less than a critical value), the driving potential VG can be pulse width modulation (Pulse Width Modulation) with a fixed switching frequency. PWM) potential VW; on the contrary, if the inductor current IL is relatively large (for example, the average value of the inductor current IL is greater than or equal to the aforementioned critical value), then the driving potential VG can be a pulse frequency modulation with a variable switching frequency. Variable (Pulse Frequency Modulation, PFM) potential VF. According to actual measurement results, the design proposed by the present invention can effectively prevent the boost inductor LU of the boost converter 100 from accidentally entering a magnetic saturation state, thereby improving the overall operational safety.

The following embodiments will introduce the detailed structure and operation of the boost converter 100 . It must be understood that these drawings and descriptions are only examples and are not intended to limit the scope of the invention.

Figure 2 is a circuit diagram of a boost converter 200 according to an embodiment of the present invention. In the embodiment of FIG. 2, the boost converter 200 has a first input node NIN1, a second input node NIN2, and an output node NOUT, and includes a bridge rectifier 210, a boost inductor LU, a Power switch 220, an output stage circuit 230, and a detection and control circuit 250. The first input node NIN1 and the second input node NIN2 of the boost converter 200 may respectively receive a first input potential VIN1 and a second input potential VIN2 from an external input power supply (not shown). The output node NOUT of the boost converter 200 can be used to output an output potential VOUT to an electronic device (not shown).

The bridge rectifier 210 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The first diode D1 has an anode and a cathode, wherein the anode of the first diode D1 is coupled to the first input node NIN1, and the cathode of the first diode D1 is coupled to a first node N1 To output the rectified potential VR. The second diode D2 has an anode and a cathode, wherein the anode of the second diode D2 is coupled to the second input node NIN2, and the cathode of the second diode D2 is coupled to the first node N1. The third diode D3 has an anode and a cathode, wherein the anode of the third diode D3 is coupled to a ground potential VSS, and the cathode of the third diode D3 is coupled to the first input node NIN1. The fourth diode D4 has an anode and a cathode, wherein the anode of the fourth diode D4 is coupled to the ground potential VSS, and the cathode of the fourth diode D4 is coupled to the second input node NIN2.

The boost inductor LU has a first terminal and a second terminal, wherein the first terminal of the boost inductor LU is coupled to the first node N1 to receive the rectified potential VR, and the second terminal of the boost inductor LU is coupled to a second node N2. In some embodiments, an inductor current IL may flow through the boost inductor LU, which will be described in detail later.

The power switch 220 includes a first transistor M1. For example, the first transistor M1 may be an N-type Metal-Oxide-Semiconductor Field-Effect Transistor (NMOSFET). The first transistor M1 has a control terminal (for example: a gate), a first terminal (for example: a source), and a second terminal (for example: a drain), wherein the control terminal of the first transistor M1 The terminal is used to receive a driving potential VG, the first terminal of the first transistor M1 is coupled to the ground potential VSS, and the second terminal of the first transistor M1 is coupled to a third node N3.

The output stage circuit 230 includes a fifth diode D5 and an output capacitor CO. The fifth diode D5 has an anode and a cathode, wherein the anode of the fifth diode D5 is coupled to the third node N3, and the cathode of the fifth diode D5 is coupled to the output node NOUT. The output capacitor CO has a first terminal and a second terminal, wherein the first terminal of the output capacitor CO is coupled to the output node NOUT, and the second terminal of the output capacitor CO is coupled to a fourth node N4. In some embodiments, an output current IOUT may flow through the output capacitor CO, which will be described in detail later.

The detection and control circuit 250 includes: an averaging circuit 252, a microcontroller unit (MCU) 254, a comparator 256, a second transistor M2, a third transistor M3, and a first resistor R1 , a second resistor R2, a third resistor R3, and a fourth resistor R4. For example, the second transistor M2 and the third transistor M3 may each be an N-type MOSFET.

The first resistor R1 has a first terminal and a second terminal, wherein the first terminal of the first resistor R1 is coupled to the second node N2, and the second terminal of the first resistor R1 is coupled to the second node N2. Three nodes N3. The aforementioned inductor current IL can further flow through the first resistor R1, so that a potential difference VD can be formed between the second node N2 and the third node N3. According to Ohm's law, this potential difference VD will be proportional to the inductor current IL. The averaging circuit 252 can calculate an average value of the potential difference VD within a predetermined period of time to generate an average potential VA. In some embodiments, the resistance value of the first resistor R1 is very small (for example, less than or equal to 10Ω), so it can almost be regarded as a short-circuit path.

The second resistor R2 has a first terminal and a second terminal, wherein the first terminal of the second resistor R2 is coupled to the fourth node N4, and the second terminal of the second resistor R2 is coupled to the ground. Potential VSS. The output current IOUT from the output stage circuit 230 can further flow through the second resistor R2, so that the second resistor R2 can provide a sensing potential VS at the fourth node N4. According to Ohm's law, the sensing potential VS will be proportional to the output current IOUT. In some embodiments, the resistance value of the second resistor R2 is very small (for example, less than or equal to 1Ω), so it can almost be regarded as another short-circuit path.

The third resistor R3 has a first terminal and a second terminal, wherein the first terminal of the third resistor R3 is used to receive the average potential VA, and the second terminal of the third resistor R3 is coupled to a fifth Node N5. The second transistor M2 has a control terminal (for example, a gate), a first terminal (for example, a source), and a second terminal (for example, a drain), wherein the control terminal of the second transistor M2 The terminal is coupled to the fifth node N5, the first terminal of the second transistor M2 is coupled to the ground potential VSS, and the second terminal of the second transistor M2 is coupled to a sixth node N6.

The fourth resistor R4 has a first terminal and a second terminal, wherein the first terminal of the fourth resistor R4 is used to receive the sensing potential VS, and the second terminal of the fourth resistor R4 is coupled to a first terminal. Seven nodes N7. The third transistor M3 has a control terminal (for example: a gate), a first terminal (for example: a source), and a second terminal (for example: a drain), wherein the control terminal of the third transistor M3 The terminal is coupled to the seventh node N7, the first terminal of the third transistor M3 is coupled to the sixth node N6, and the second terminal of the third transistor M3 is coupled to an eighth node N8.

The microcontroller 254 can generate a reference potential VE. The reference potential VE can be a fixed potential, such as 2.5V, but is not limited to this. The comparator 256 has a positive input terminal, a negative input terminal, and an output terminal, wherein the positive input terminal of the comparator 256 is used to receive the reference potential VE, and the negative input terminal of the comparator 256 is coupled to the eighth node N8 , and the output terminal of the comparator 256 is used to output a comparison potential VB. In addition, the microcontroller 254 can also generate and determine the aforementioned driving potential VG according to the comparison potential VB, so that the driving potential VG can be a pulse width modulation potential VW with a fixed switching frequency, or it can be a pulse width modulation potential VW with a fixed switching frequency. One of the variable switching frequencies, pulse frequency modulation potential VF, can be selected from the two.

Figure 3 is a waveform diagram showing the inductor current IL of the boost inductor LU according to an embodiment of the present invention. In some embodiments, the boost inductor LU can operate in a Discontinuous Current Mode (DCM), a Boundary Current Mode (BCM), or a Continuous Current Mode (Continuous Current Mode, CCM) Choose one of the three. For example, during a first time interval T1, the boost inductor LU operates in the discontinuous current mode; during a second time interval T2, the boost inductor LU operates in the boundary current mode; and during a second time interval T2, the boost inductor LU operates in the boundary current mode. During the third time interval T3, the boost inductor LU operates in the continuous current mode.

In some embodiments, the operating principle of the boost converter 200 may be as follows. Generally speaking, the detection and control circuit 250 can determine an operation mode of the boost inductor LU based on the average potential VA or/and the sensing potential VS. If the boost inductor LU operates in the discontinuous current mode or the boundary current mode, the inductor current IL and the output current IOUT are relatively small, so that the second transistor M2 and the third transistor M3 are maintained in the off state. On the contrary, if the boost inductor LU operates in the continuous current mode, the inductor current IL and the output current IOUT are relatively large, so that the average potential VA is enough to turn on the second transistor M2 and the sensing potential VS is enough to turn on the third transistor M3 .

When the boost inductor LU operates in the discontinuous current mode or the boundary current mode, the eighth node N8 will be in a floating state, so the comparator 256 will not output any comparison potential VB. Since the comparison potential VB is not received, the microcontroller 254 will determine that the driving potential VG becomes the pulse width modulation potential VW with a fixed switching frequency.

When the boost inductor LU operates in the continuous current mode, the potential V8 at the eighth node N8 can be almost pulled down to the ground potential VSS by the second transistor M2 and the third transistor M3, so the comparator 256 will output a high logic bit Accurate comparison potential VB. In response to the aforementioned comparison potential VB, the microcontroller 254 will determine the driving potential VG to become a pulse frequency modulated potential VF with a variable switching frequency.

Figure 4 is a waveform diagram showing the driving potential VG and the inductor current IL according to an embodiment of the present invention. As shown in FIG. 4 , each operation period TT of the driving potential VG includes a high logic interval TN and a low logic interval TF. In the embodiment of FIG. 4 , the driving potential VG is a pulse width modulation potential VW with a fixed switching frequency. If the boost inductor LU operates in the discontinuous current mode, the length of the low logic interval TF of the driving potential VG will be greater than the length of its high logic interval TN. In addition, if the boost inductor LU operates in the boundary current mode, the length of the low logic interval TF of the driving potential VG will be exactly the same as the length of the high logic interval TN. It must be noted that whether it is discontinuous current mode or boundary current mode, the switching frequency of the driving potential VG will not change.

FIG. 5 shows a waveform diagram of the driving potential VG and the inductor current IL according to another embodiment of the present invention. In the embodiment of FIG. 5, the driving potential VG is a pulse frequency modulated potential VF with a variable switching frequency. If the boost inductor LU operates in the continuous current mode, the microcontroller 254 will appropriately adjust the switching frequency or/and the duty cycle of the driving potential VG, and at the same time force the length of the low logic interval TF of the driving potential VG to be exactly equal to the length of the low logic interval TF of the driving potential VG. The length of the high logic interval TN. According to the actual measurement results, the pulse frequency modulation potential VF of this design can prevent the boost inductor LU from being charged again before it is completely discharged. Therefore, the boost inductor LU will be less likely to accidentally enter magnetic saturation due to continuous current mode.

The present invention proposes a novel boost converter that can be used to reduce the risk of magnetic saturation. According to the actual measurement results, using the boost converter designed as mentioned above will effectively improve the overall operational safety, so it is very suitable for application in various types of devices.

It is worth noting that the above-mentioned potential, current, resistance value, inductance value, capacitance value, and other component parameters are not limiting conditions of the present invention. Designers can adjust these settings according to different needs. The boost converter of the present invention is not limited to the state shown in Figures 1-5. The present invention may only include any one or multiple features of any one or multiple embodiments of Figures 1-5. In other words, not all features shown in the figures need to be implemented in the boost converter of the present invention at the same time. Although the embodiment of the present invention uses a metal oxide semi-field effect transistor as an example, the present invention is not limited thereto. Those skilled in the art can use other types of transistors, such as junction field effect transistors or fins. type field effect transistor, etc., without affecting the effect of the present invention.

The ordinal numbers in this specification and the scope of the patent application, such as "first", "second", "third", etc., have no sequential relationship with each other. They are only used to distinguish two items with the same Different components with names.

Although the present invention is disclosed above in terms of preferred embodiments, they are not intended to limit the scope of the present invention. Anyone skilled in the art can make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the appended patent application scope.

100,200:Boost converter 110,210: Bridge rectifier 120,220:Power switcher 130,230: Output stage circuit 150,250: Detection and control circuit 252:Averaging circuit 254:Microcontroller 256: Comparator CO: output capacitor D1: first diode D2: Second diode D3: The third diode D4: The fourth diode D5: The fifth diode IL: inductor current IOUT: output current LU: Boost inductor M1: the first transistor M2: Second transistor M3: The third transistor N1: first node N2: second node N3: The third node N4: fourth node N5: fifth node N6: The sixth node N7: The seventh node N8: The eighth node NIN1: first input node NIN2: second input node NOUT: output node R1: first resistor R2: second resistor R3: The third resistor R4: The fourth resistor T1: the first time interval T2: The second time interval T3: The third time interval TT: operating cycle TF: low logic range TN: high logic interval V8:potential VA: average potential VB: comparison potential VD: potential difference VE: reference potential VF: pulse frequency modulation potential VG: driving potential VIN1: first input potential VIN2: second input potential VOUT: output potential VR: rectifier potential VS: sensing potential VSS: ground potential VW: pulse width modulation potential

Figure 1 is a schematic diagram of a boost converter according to an embodiment of the present invention. Figure 2 is a circuit diagram showing a boost converter according to an embodiment of the present invention. Figure 3 is a waveform diagram showing the inductor current of the boost inductor according to an embodiment of the present invention. FIG. 4 is a waveform diagram showing the driving potential and the inductor current according to an embodiment of the present invention. FIG. 5 is a waveform diagram showing the driving potential and the inductor current according to another embodiment of the present invention.

100:Boost converter

110: Bridge rectifier

120:Power switcher

130:Output stage circuit

150: Detection and control circuit

IL: inductor current

LU: Boost inductor

VF: pulse frequency modulation potential

VG: driving potential

VIN1: first input potential

VIN2: second input potential

VOUT: output potential

VR: rectifier potential

VSS: ground potential

VW: pulse width modulation potential

Claims (10)

A boost converter that suppresses magnetic saturation, including: A bridge rectifier generates a rectified potential based on a first input potential and a second input potential; A boost inductor receives the rectified potential, and an inductor current flows through the boost inductor; a power switch that selectively couples the boost inductor to a ground potential based on a driving potential; An output stage circuit is coupled to the boost inductor and generates an output potential; and a detection and control circuit that monitors the boost inductor and generates the driving potential based on the inductor current; If the inductor current is relatively small, the driving potential is a pulse width modulation (PWM) potential with a fixed switching frequency; If the inductor current is relatively large, the driving potential is a pulse frequency modulation (PFM) potential with a variable switching frequency. The boost converter of claim 1, wherein the boost inductor operates in a discontinuous current mode, a boundary current mode, or a continuous current mode. The boost converter of claim 2, wherein when the boost inductor operates in the discontinuous current mode or the boundary current mode, the driving potential is the pulse width modulation potential with the fixed switching frequency, When the boost inductor operates in the continuous current mode, the driving potential is the pulse frequency modulated potential with the variable switching frequency. The boost converter of claim 1, wherein the bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode of the first diode is coupled to a first input node to receive the first input potential, and the first diode The cathode is coupled to a first node to output the rectified potential; a second diode having an anode and a cathode, wherein the anode of the second diode is coupled to a second input node to receive the second input potential, and the The cathode is coupled to the first node; a third diode having an anode and a cathode, wherein the anode of the third diode is coupled to the ground potential, and the cathode of the third diode is coupled to the first input node; and a fourth diode having an anode and a cathode, wherein the anode of the fourth diode is coupled to the ground potential, and the cathode of the fourth diode is coupled to the second input node; The boost inductor has a first terminal and a second terminal, the first terminal of the boost inductor is coupled to the first node to receive the rectified potential, and the second terminal of the boost inductor The terminal is coupled to a second node. The boost converter of claim 4, wherein the power switcher includes: A first transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor is used to receive the driving potential, and the first terminal of the first transistor is coupled to the ground potential, and the second terminal of the first transistor is coupled to a third node. The boost converter of claim 5, wherein the output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the third node, and the cathode of the fifth diode is coupled to an output node to output the output potential; and An output capacitor has a first terminal and a second terminal, wherein the first terminal of the output capacitor is coupled to the output node, and the second terminal of the output capacitor is coupled to a fourth node. For example, the boost converter of claim 6, wherein the detection and control circuit includes: A first resistor having a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the second node, and the second terminal of the first resistor is coupled to is connected to the third node, and the inductor current further flows through the first resistor, so that a potential difference is formed between the second node and the third node; an averaging circuit that calculates an average of the potential differences to generate an average potential; and a second resistor having a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the fourth node, and the second terminal of the second resistor is coupled to is connected to the ground potential, and one of the output currents further flows through the second resistor, so that the second resistor can provide a sensing potential at the fourth node. For example, the boost converter of claim 7, wherein the detection and control circuit further includes: A third resistor having a first end and a second end, wherein the first end of the third resistor is used to receive the average potential, and the second end of the third resistor is coupled to a fifth node; and A second transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is coupled to the fifth node, and the first terminal of the second transistor A terminal is coupled to the ground potential, and the second terminal of the second transistor is coupled to a sixth node. For example, the boost converter of claim 8, wherein the detection and control circuit further includes: A fourth resistor having a first end and a second end, wherein the first end of the fourth resistor is used to receive the sensing potential, and the second end of the fourth resistor is coupled to a seventh node; and A third transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the third transistor is coupled to the seventh node, and the first terminal of the third transistor A terminal is coupled to the sixth node, and the second terminal of the third transistor is coupled to an eighth node. For example, the boost converter of claim 9, wherein the detection and control circuit further includes: a microcontroller generating a reference potential; and A comparator has a positive input terminal, a negative input terminal, and an output terminal, wherein the positive input terminal of the comparator is used to receive the reference potential, and the negative input terminal of the comparator is coupled to the The eighth node, and the output terminal of the comparator is used to output a comparison potential; The microcontroller further generates and determines the driving potential according to the comparison potential.

Images