Switching charger for supplying stable power

Abstract

The application discloses a switching charger for supplying stable power. A first input terminal of a first operational amplifier, a second input terminal of a second operational amplifier and a first input terminal of a fourth operational amplifier are connected to a battery. A second input terminal of the first operational amplifier is coupled to a reference voltage. A first input terminal of the second operational amplifier and a second input terminal of the fourth operational amplifier are connected to an inductor. A first input terminal of a third operational amplifier is connected to an input power supply. A second input terminal of the third operational amplifier is connected to a system circuit. A first selection circuit is connected to output terminals of the third operational amplifier and the fourth operational amplifier. A second selection circuit is connected to output terminals of the first operational amplifier, the second operational amplifier and the first selection circuit.

Description

Technical Field

[0001] This invention relates to a switching charger that supplies stable power, and more particularly to a switching charger that supplies stable power. Background Technology

[0002] In recent years, with the advancement of technology, electronic products with various functions have been developed, not only meeting people's diverse needs but also integrating into everyone's daily life, making life more convenient. These electronic products are composed of various electronic components, and each component requires a different power supply voltage. Therefore, in order for these diverse electronic products to operate normally, a switching charger is needed to convert the input voltage to an appropriate voltage for the electronic components. However, when electronic products require a large amount of power, the switching components of existing switching chargers cannot switch quickly enough, failing to provide sufficient and stable power to the electronic products in real time. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a switching charger that provides stable power supply, addressing the shortcomings of existing technologies. The switching charger includes a switching circuit, multiple operational amplifiers, a first selection circuit, a second selection circuit, and a control circuit. The switching circuit is connected to an input power supply and a first terminal of an inductor. The second terminal of the inductor is connected to a battery. The multiple operational amplifiers include a first operational amplifier, a second operational amplifier, a third operational amplifier, and a fourth operational amplifier. The first input terminal of the first operational amplifier is connected to the battery. The second input terminal of the first operational amplifier is coupled to a first reference voltage. The first input terminal of the second operational amplifier is connected to a second terminal of the inductor. The second input terminal of the second operational amplifier is connected to the battery. The first input terminal of the third operational amplifier is connected to the input power supply. The second input terminal of the third operational amplifier is connected to a system circuit. The first input terminal of the fourth operational amplifier is connected to the battery. The second input terminal of the fourth operational amplifier is connected to a second terminal of the inductor. The first selection circuit connects the output terminals of the third and fourth operational amplifiers. The first selection circuit is configured to select the signal output by one of the third and fourth operational amplifiers to output a first selection signal. The second selection circuit connects the output terminals of the first and second operational amplifiers and the output terminal of the first selection circuit. The second selection circuit is configured to select one of the signals output by the first operational amplifier, the second operational amplifier, and the first selection signal, to output a second selection signal. A control circuit is connected to the second selection circuit and the switching circuit. The control circuit is configured to control the operation of the switching circuit based on the second selection signal.

[0004] In one embodiment, the switching charger providing stable power further includes a voltage divider circuit. The input of the voltage divider circuit is connected to the battery. The output of the voltage divider circuit is connected to the first input of a first operational amplifier.

[0005] In this embodiment, the voltage divider circuit includes a first voltage divider resistor and a second voltage divider resistor. A first terminal of the first voltage divider resistor is connected to the battery. A first terminal of the second voltage divider resistor is connected to a second terminal of the first voltage divider resistor and a first input terminal of the first operational amplifier. The second terminal of the second voltage divider resistor is grounded.

[0006] In this embodiment, the switching circuit includes an upper bridge switch and a lower bridge switch. A first terminal of the upper bridge switch is connected to an input power supply. A control terminal of the upper bridge switch is connected to a control circuit. A first terminal of the lower bridge switch is connected to a second terminal of the upper bridge switch. The second terminal of the lower bridge switch is grounded. The node between the first terminal of the lower bridge switch and the second terminal of the upper bridge switch is connected to the first terminal of an inductor. The control terminal of the lower bridge switch is connected to the control circuit.

[0007] In one embodiment, the plurality of operational amplifiers further includes a fifth operational amplifier. A first input terminal of the fifth operational amplifier is connected to the output terminal of the second operational amplifier. A second input terminal of the fifth operational amplifier is coupled to a second reference voltage. The output terminal of the fifth operational amplifier is connected to a second selection circuit. The second selection circuit is configured to select one of the signal output from the first operational amplifier, the signal output from the fifth operational amplifier, and the first selection signal to output a second selection signal.

[0008] In one embodiment, the plurality of operational amplifiers further includes a sixth operational amplifier. A first input terminal of the sixth operational amplifier is connected to the output terminal of a third operational amplifier. A second input terminal of the sixth operational amplifier is coupled to a third reference voltage. The output terminal of the sixth operational amplifier is connected to a first selection circuit. The first selection circuit is configured to select the signal output from either the sixth operational amplifier or a fourth operational amplifier to output a first selection signal.

[0009] In one embodiment, the plurality of operational amplifiers further includes a seventh operational amplifier. A first input terminal of the seventh operational amplifier is coupled to a fourth reference voltage. A second input terminal of the seventh operational amplifier is connected to the output terminal of the fourth operational amplifier. The output terminal of the seventh operational amplifier is connected to a first selection circuit. The first selection circuit is configured to select the signal output from either the sixth or seventh operational amplifier to output a first selection signal.

[0010] In one embodiment, the switching charger providing stable power further includes a sensing resistor. A first terminal of the sensing resistor is connected to a first input terminal of a second operational amplifier, a second input terminal of a fourth operational amplifier, and a second terminal of an inductor. A second terminal of the sensing resistor is connected to a second input terminal of the second operational amplifier, a first input terminal of the fourth operational amplifier, and a battery.

[0011] In this embodiment, the switching charger providing stable power further includes an input resistor. A first terminal of the input resistor is connected to the input power supply and the first input terminal of the third operational amplifier. A second terminal of the input resistor is connected to the second input terminal of the third operational amplifier, the switching circuit, and the system circuit.

[0012] In one embodiment, the switching charger supplying stable power further includes a first switching assembly, a second switching assembly, and a first switching circuit. A first terminal of the first switching assembly is connected to an input power source. A first terminal of the second switching assembly is connected to a second terminal of the first switching assembly. The second terminal of the second switching assembly is connected to a first terminal of an input resistor. The first switching circuit is connected to the control terminals of both the first and second switching assemblies. The first switching circuit is configured to switch between the first and second switching assemblies.

[0013] In one embodiment, the switching charger supplying stable power further includes an error amplifier. A first input terminal of the error amplifier is connected to the output terminal of a second selection circuit. A second input terminal of the error amplifier is coupled to a first reference voltage. The output terminal of the error amplifier is connected to the input terminal of a control circuit.

[0014] In one embodiment, the switching charger providing stable power further includes an operational amplifier. A first input terminal of the operational amplifier is connected to the output terminal of an error amplifier. A second input terminal of the operational amplifier is connected to the output terminal of an oscillation circuit. The output terminal of the operational amplifier is connected to the input terminal of a control circuit.

[0015] In one embodiment, the switching charger providing stable power further includes a first resistor, a first capacitor, and a second capacitor. A first terminal of the first resistor is connected to the output of a second selection circuit. A first terminal of the first capacitor is connected to the second terminal of the first resistor. A second terminal of the first capacitor is connected to the first input of an error amplifier. A first terminal of the second capacitor is connected to the first input of the error amplifier. A second terminal of the second capacitor is connected to the output of the error amplifier.

[0016] In this embodiment, the switching charger providing stable power further includes a second resistor, a third resistor, and a third capacitor. The first terminal of the second resistor is connected to the output of the second selection circuit. The first terminal of the third resistor is connected to the first input of the error amplifier. The first terminal of the third capacitor is connected to the second terminal of the third resistor. The second terminal of the third capacitor is connected to the output of the error amplifier.

[0017] As described above, the present invention provides a switching charger that supplies stable power. The circuit components used in this charger are configured differently from those in traditional switching chargers, and perform different operations, thereby making the voltage and current signals output by the circuit components more stable.

[0018] To further understand the features and technical content of the present invention, please refer to the following detailed description and illustrations of the present invention. However, the illustrations provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0019] Figure 1 This is a circuit diagram of a switching charger that provides stable power according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the current flow path of a switching charger supplying stable power in an embodiment of the present invention when it is not in turboboost mode.

[0021] Figure 3 This is a schematic diagram of the current flow path when a switching charger supplying stable power enters the accelerated boost mode, according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the current flow in a switching charger that supplies stable power according to an embodiment of the present invention.

[0023] Figure 5 The waveform diagram shows the signal of a switching charger that supplies stable power according to an embodiment of the present invention. Detailed Implementation

[0024] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can understand the advantages and effects of the present invention from the content disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. Furthermore, the accompanying drawings of the present invention are for simple illustrative purposes only and are not depictions of actual dimensions, as stated in advance. The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" as used herein may, depending on the actual situation, include any combination of any one or more of the associated listed items.

[0025] Please see Figure 1 This is a circuit diagram of a switching charger that supplies stable power according to an embodiment of the present invention.

[0026] The switching charger of this invention may include, as in the following embodiments: Figure 1 The circuit shown includes a switching circuit SWC, a first operational amplifier 101, a second operational amplifier 102, a third operational amplifier 103, a fourth operational amplifier 104, a first selection circuit 201, a second selection circuit 202, and a control circuit 300.

[0027] If necessary, the switching charger of this embodiment of the invention may further include one or more of the following: a fifth operational amplifier 105, a sixth operational amplifier 106, a seventh operational amplifier 107, a voltage divider circuit VDR, a sensing resistor RSR, an input resistor RAC, a first switching component Q1, a second switching component Q2, a third switching component Q3, a first switching circuit 601, a second switching circuit 602, an error amplifier ERA, an eighth operational amplifier 108, a first resistor R1, a first capacitor C1, a second capacitor C2, a second resistor R2, a third resistor R3, a third capacitor C3, a first Zener diode D1, a second Zener diode D2, a protection circuit 400, and an enable circuit 500.

[0028] In this embodiment, a switching charger that supplies stable power is described in detail as including, for example... Figure 1 The configuration relationships between all circuit components shown are merely illustrative and not intended to limit the invention. In practice, the switching charger for supplying stable power according to the present invention may only include the following components: Figure 1 The circuit components shown are only a portion of the total circuit components; other circuit components may be omitted as appropriate.

[0029] First, a first Zener diode D1 and a second Zener diode D2 can be placed between the input power supply for supplying the input voltage VBUS and the system circuit 600. The input power supply can be connected to the first terminal of capacitor Cin. The input current supplied by the input power supply can flow to capacitor Cin to charge the voltage of capacitor Cin to the input voltage VBUS. The input current supplied by the input power supply can also flow to the system circuit 800, or to both the system circuit 800 and the battery BAT.

[0030] A first switching assembly Q1, a second switching assembly Q2, and an input resistor RAC can be provided between the input power supply, which provides the input voltage VBUS, and the system circuit 800. The first terminal of the first switching assembly Q1 can be connected to the input power supply or the first terminal of the capacitor Cin. The second terminal of the capacitor Cin is grounded.

[0031] The second terminal of the first switching component Q1 can be connected to the first terminal of the second switching component Q2. The second terminal of the second switching component Q2 can be connected to the first terminal of the input resistor RAC. The second terminal of the input resistor RAC can be connected to the system circuit 800 and the first terminal of the output capacitor Cout. The second terminal of the output capacitor Cout can be grounded.

[0032] The first switching circuit 601 can be connected to the control terminal of the first switching component Q1 and the control terminal of the second switching component Q2. The first switching circuit 601 can switch the first switching component Q1 and the second switching component Q2 to be on or off, so as to allow or disable the input current supplied by the input power supply to the system circuit 800 (and the battery BAT).

[0033] The switching circuit SWC may include an upper bridge switch UG and a lower bridge switch LG. The control terminal of the upper bridge switch UG can be connected to the output terminal of the control circuit 300. A NOT gate NVR can be set between the control terminal of the lower bridge switch LG and the control circuit 300. The first terminal of the NOT gate NVR can be connected to the output terminal of the control circuit 300. The output terminal of the NOT gate NVR can be connected to the control terminal of the lower bridge switch LG.

[0034] The first terminal of the upper bridge switch UG can be connected to the second terminal of the input resistor RAC. The first terminal of the lower bridge switch LG can be connected to the second terminal of the upper bridge switch UG. The second terminal of the lower bridge switch LG is grounded. The node LX between the first terminal of the lower bridge switch LG and the second terminal of the upper bridge switch UG can be connected to the first terminal of the inductor L. The second terminal of the inductor L can be connected to the first terminal SRP of the sensing resistor RSR. The second terminal SRN of the sensing resistor RSR can be connected to the battery BT.

[0035] The first terminal of the third switching component Q3 can be connected to the second terminal of the input resistor RAC. The second terminal of the third switching component Q3 can be connected to the second terminal of the inductor L and the first terminal SRP of the sensing resistor RSR. The second switching circuit 602 can be connected to the control terminal and the second terminal of the third switching component Q3. The second switching circuit 602 can switch the third switching component Q3 on or off.

[0036] It is worth noting that the first input terminal of the first operational amplifier 101, such as the non-inverting input terminal, can be connected to the second terminal SRN of the sensing resistor SRN and the battery BT to obtain the voltage at the second terminal SRN of the sensing resistor SRN (i.e., the battery voltage VBAT). The second input terminal of the first operational amplifier 101, such as the inverting input terminal, can be coupled to the first reference voltage Vref1. The output terminal of the first operational amplifier 101 is connected to the input terminal of the second selection circuit 202.

[0037] The first operational amplifier 101 can multiply the difference between the voltage at the second terminal SRN of the sensing resistor SRN (i.e., the battery voltage VBAT) and the first reference voltage Vref1 by a first gain to output a first amplified signal to the second selection circuit 202.

[0038] If necessary, a voltage divider circuit VDR can be configured. The voltage divider circuit VDR can be connected between the first input terminal of the first operational amplifier 101 (e.g., the non-inverting input terminal) and the second terminal SRN of the sensing resistor SRN, and can also be connected between the first input terminal of the first operational amplifier 101 and the battery BT.

[0039] The input terminal of the voltage divider circuit VDR can be connected to the battery BT. The output terminal of the voltage divider circuit VDR can be connected to the first input terminal of the first operational amplifier 101.

[0040] In detail, the voltage divider circuit VDR may include a first voltage divider resistor Rd1 and a second voltage divider resistor Rd2. The first terminal of the first voltage divider resistor Rd1 can be connected to the second terminal SRN of the sensing resistor SRN and the battery BT. The first terminal of the second voltage divider resistor Rd2 can be connected to the second terminal of the first voltage divider resistor Rd1 and the first input terminal of the first operational amplifier 101, such as the non-inverting input terminal. The second terminal of the second voltage divider resistor Rd2 is grounded.

[0041] If a voltage divider circuit VDR is provided, the first operational amplifier 101 can multiply the difference between the voltage at the second terminal SRN of the sensing resistor SRN (i.e., the voltage of the battery BT) after being divided by the voltage divider resistor VDR and the first reference voltage Vref1 by the first gain, so as to output the first amplified signal to the second selection circuit 202.

[0042] The first input terminal of the second operational amplifier 102, such as the non-inverting input terminal, can be connected to the first terminal SRP of the sensing resistor RSR and the second terminal of the inductor L. The second input terminal of the second operational amplifier 102, such as the inverting input terminal, can be connected to the second terminal SRN of the sensing resistor RSR and the battery BT.

[0043] The second operational amplifier 102 can multiply the difference between the voltage at the first terminal SRP of the sensing resistor RSR and the voltage at the second terminal SRN of the sensing resistor RSR by a second gain to output a second amplified signal.

[0044] The first input terminal of the fifth operational amplifier 105, such as the non-inverting input terminal, can be connected to the output terminal of the second operational amplifier 102 to receive a second amplified signal from the output terminal of the second operational amplifier 102. The second input terminal of the fifth operational amplifier 105, such as the inverting input terminal, can be coupled to a second reference voltage Vref2. The output terminal of the fifth operational amplifier 105 can be connected to the input terminal of the second selection circuit 202.

[0045] The fifth operational amplifier 105 can multiply the difference between the voltage of the second amplified signal from the second operational amplifier 102 and the second reference voltage Vref2 by the fifth gain to output the fifth amplified signal.

[0046] The first input terminal of the third operational amplifier 103, for example, the non-inverting input terminal, can be connected to the first terminal ACP of the input resistor RAC. The second input terminal of the third operational amplifier 103, for example, the inverting input terminal, can be connected to the second terminal ACN of the input resistor RAC. The third operational amplifier 103 can multiply the difference between the voltage at the first terminal ACP of the input resistor RAC and the voltage at the second terminal ACN of the input resistor RAC by a third gain to output a third amplified signal.

[0047] The first input terminal of the sixth operational amplifier 106, such as the non-inverting input terminal, can be connected to the output terminal of the third operational amplifier 103 to receive a third amplified signal from the output terminal of the third operational amplifier 103. The second input terminal of the sixth operational amplifier 106, such as the inverting input terminal, can be coupled to a third reference voltage Vref3. The output terminal of the sixth operational amplifier 106 can be connected to the input terminal of the first selection circuit 201.

[0048] The sixth operational amplifier 106 can multiply the difference between the voltage of the third amplified signal from the third operational amplifier 103 and the third reference voltage Vref3 by a sixth gain to output the sixth amplified signal to the first selection circuit 201.

[0049] The switching charger of this invention can be applied to system circuit 800. When system circuit 800 requires a large amount of energy, the entire operation process is described below.

[0050] When the system circuit 800 requires a large amount of energy and the current flowing through the input resistor RAC exceeds the current threshold, a boost mode trigger signal is output, and the input current supplied by the input power supply is clamped. In boost mode, not only does the input current supplied by the input power supply flow sequentially through the first switching component Q1, the second switching component Q2, and the input resistor RAC to the system circuit 800, but a discharge current supplied by the battery BT also flows sequentially through the sensing resistor RSR, the inductor L, and the upper bridge switch UG to the system circuit 800.

[0051] As the energy required by the system circuit 800 continues to increase, a discharge current is supplied by the battery BT. However, when the current flowing through the sensing resistor RSR exceeds the current threshold, the discharge current of the battery BT is clamped in order to protect the battery BT. At the same time, the input current supplied by the input power supply, which was originally clamped, will be released and supply the energy required by the system circuit 800.

[0052] It is worth noting that, in order to achieve the above operation, the switching charger of this embodiment of the invention is provided with a fourth operational amplifier 104 and a seventh operational amplifier 107, and a first selection circuit 201 is provided at the output of the sixth operational amplifier 106 and the seventh operational amplifier 107, which is used to continuously judge (it will be continuously turned on regardless of whether it enters the acceleration boost mode, so there will be no switching problem).

[0053] The fourth operational amplifier 104, the seventh operational amplifier 107, and the configuration of the seventh operational amplifier 107 with other circuit components are described in detail below.

[0054] The first input terminal of the fourth operational amplifier 104, such as the non-inverting input terminal, can be connected to the second terminal SRN of the sensing resistor RSR and the battery BT. The second input terminal of the fourth operational amplifier 104, such as the inverting input terminal, can be connected to the first terminal SRP of the sensing resistor RSR and the second terminal of the inductor L.

[0055] The fourth operational amplifier 104 can multiply the difference between the voltage at the first terminal SRP of the sensing resistor RSR (i.e., the voltage at the second terminal of the inductor L) and the voltage at the second terminal SRN of the sensing resistor RSR (the battery voltage VBAT) by a fourth gain to output a fourth amplified signal.

[0056] The first input terminal of the seventh operational amplifier 107, such as the non-inverting input terminal, can be connected to the fourth reference voltage Vref4. The second input terminal of the seventh operational amplifier 107, such as the inverting input terminal, can be connected to the output terminal of the fourth operational amplifier 104 to receive the fourth amplified signal from the output terminal of the fourth operational amplifier 104. The output terminal of the seventh operational amplifier 107 can be connected to the input terminal of the first selection circuit 201.

[0057] The seventh operational amplifier 107 can multiply the difference between the fourth reference voltage Vref4 and the voltage of the fourth amplified signal from the fourth operational amplifier 104 by the seventh gain to output the seventh amplified signal to the input of the first selection circuit 201.

[0058] The first selection circuit 201 can select one of the sixth amplified signal output from the sixth operational amplifier 106 and the seventh amplified signal output from the seventh operational amplifier 107 to output the first selection signal to the second selection circuit 202.

[0059] Furthermore, the input terminal of the second selection circuit 202 can be connected to the output terminal of the first operational amplifier 101, the output terminal of the fifth operational amplifier 105, and the output terminal of the first selection circuit 201.

[0060] The second selection circuit 202 can select one of the first amplified signal from the first operational amplifier 101, the fifth amplified signal from the fifth operational amplifier 105, and the first selection signal from the first selection circuit 201 to output the second selection signal.

[0061] It is worth noting that when the battery BT auxiliary supply discharges a current through the sensing resistor RSR, and this discharge current is greater than the current threshold, the first selection circuit 201 will select the outputs of the fourth operational amplifier 104 and the seventh operational amplifier 107, and the second selection circuit 202 will select the output of the first selection circuit 201, which will clamp the discharge current of the battery BT to a set current value.

[0062] The control circuit 300 can be directly connected to or connected to the output of the second selection circuit 202 through other circuit components. The control circuit 300 can control the operation of the upper bridge switch UG and the lower bridge switch LG based on the received (processed by other circuit components) second selection signal.

[0063] If necessary, other circuit components may be provided between the output of the second selection circuit 202 and the input of the control circuit 300, as detailed below.

[0064] The first input terminal of the error amplifier ERA, such as the inverting input terminal, can be connected to the output terminal of the second selection circuit 202 (through the first resistor R1 and the first capacitor C1). The second input terminal of the error amplifier ERA, such as the non-inverting input terminal, can be coupled to the first reference voltage Vref1.

[0065] The first terminal of the first resistor R1 can be connected to the output terminal of the second selection circuit 202. The second terminal of the first resistor R1 can be connected to the first terminal of the first capacitor C1. The second terminal of the first capacitor C1 can be connected to the first input terminal of the error amplifier ERA. The first terminal of the second capacitor C2 can be connected to the first input terminal of the error amplifier ERA. The second terminal of the second capacitor C2 can be connected to the output terminal of the error amplifier ERA.

[0066] The first terminal of the second resistor R2 can be connected to the output terminal of the second selection circuit 202. The second terminal of the second resistor R2 can be connected to the first terminal of the third resistor R3 and the first input terminal of the error amplifier ERA, such as the non-inverting input terminal. The second terminal of the third resistor R3 can be connected to the first terminal of the third capacitor C3. The second terminal of the third capacitor C3 can be connected to the output terminal of the error amplifier ERA.

[0067] The first input terminal of the eighth operational amplifier 108, such as the non-inverting input terminal, can be connected to the output terminal of the error amplifier ERA. The second input terminal of the eighth operational amplifier 108, such as the inverting input terminal, can be connected to the output terminal of the oscillator circuit 900. The output terminal of the eighth operational amplifier 108 can be connected to the input terminal of the control circuit 300.

[0068] The eighth operational amplifier 108 can multiply the difference between the voltage of an error amplified signal generated by the error amplifier ERA and the voltage of an oscillation signal generated by the oscillation circuit 900 by the eighth gain, so as to output the eighth operational amplified signal to the control circuit 300.

[0069] The control circuit 300 can control the operation of the upper bridge switch UG and the lower bridge switch LG based on the eighth operational amplifier signal received from the eighth operational amplifier 108.

[0070] If necessary, the protection circuit 400 can determine multiple reference voltages, such as the first reference voltage Vref1, the second reference voltage Vref2, the third reference voltage Vref3, and the fourth reference voltage Vref4, based on limiting condition parameters (such as overcurrent threshold or overvoltage threshold), and control the enable circuit 500 to output multiple reference voltages and enable the control circuit 300 to operate.

[0071] Please see Figure 1 and Figure 2 ,in Figure 2 This is a schematic diagram of the current flow path of a switching charger supplying stable power in an embodiment of the present invention when it is not in turbo boost mode.

[0072] When the energy required by the system circuit 800 is small and the input power supply can provide sufficient energy to the system circuit 800, the switching charger of the present invention does not need to enter the boost mode. In the non-boost mode, only the input power supply provides the input current to flow sequentially through the first switching component Q1, the second switching component Q2, and the input resistor RAC to the system circuit 800. At this time, the battery BT does not need to supply power to the system circuit 800.

[0073] When the energy required by the system circuit 800 is small and the energy of the battery BT is insufficient, but the input power supply can provide sufficient energy to both the system circuit 800 and the battery BT, the switching charger of the present invention does not need to enter the boost mode. In this case, energy can be supplied to both the system circuit 800 and the battery BT solely by the input power supply. At this time, the battery BT does not need to supply power to the system circuit 800.

[0074] like Figure 2 As shown, the input current supplied by the power supply can be divided into a first input current and a second input current. The first input current flows sequentially through the first switching component Q1, the second switching component Q2, and the input resistor RAC to the system circuit 800. The second input current flows sequentially through the upper bridge switch UG, the inductor L, and the sensing resistor RSR to the battery BT.

[0075] Please see Figure 1 and Figure 3 ,in Figure 3 This is a schematic diagram of the current flow path when a switching charger supplying stable power enters the accelerated boost mode, according to an embodiment of the present invention.

[0076] When the system circuit 800 requires a large amount of energy and the input power supply cannot provide sufficient energy, the switching charger of this invention needs to enter a boost mode. In boost mode, not only does the input power supply provide an input current that flows sequentially through the first switching component Q1, the second switching component Q2, and the input resistor RAC to the system circuit 800, but the battery BT also provides a discharge current that flows sequentially through the sensing resistor RSR, the inductor L, and the upper bridge switch UG to the system circuit 800. In this way, the system circuit 800 can obtain sufficient energy for operation.

[0077] Please see Figure 1 , Figure 4 and Figure 5 ,in Figure 4 This is a schematic diagram of the current flow in a switching charger that supplies stable power according to an embodiment of the present invention. Figure 5 The waveform diagram shows the signal of a switching charger that supplies stable power according to an embodiment of the present invention.

[0078] like Figure 4 As shown, in the switching charger of this embodiment of the invention, the input current iadp supplied by the input power supply (connected to the first end of the input capacitor Cin) can be divided into a first input current isys and a second input current ivi, which flow to the system circuit 800 and the battery BT, respectively.

[0079] like Figure 5 As shown, the waveform of the input current iadp supplied by the switching charger of this embodiment is smoother than the waveform of the input current iadp0 supplied by a conventional switching charger. The waveform of the second input current ivi supplied by the switching charger of this embodiment is smoother than the waveform of the second input current ivi0 supplied by a conventional switching charger, and there is no mode switching problem at the boundary. Therefore, the power provided by the switching charger of this embodiment is more stable than that of a conventional switching charger.

[0080] In summary, the present invention provides a switching charger that supplies stable power. The circuit components used in this charger are configured differently from those in traditional switching chargers, and perform different operations, thereby making the voltage and current signals output by the circuit components more stable.

[0081] The above-disclosed content is only a preferred embodiment of the present invention and is not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made based on the description and illustrations of the present invention are included in the claims of the present invention.

Claims

1. A switching charger that supplies stable power, characterized in that, The switching charger that supplies stable power includes: A switching circuit is connected to an input power supply and the first terminal of an inductor, and the second terminal of the inductor is connected to a battery. Multiple operational amplifiers, including: A first operational amplifier, wherein a first input terminal of the first operational amplifier is connected to the battery, and a second input terminal of the first operational amplifier is coupled to a first reference voltage; A second operational amplifier, wherein the first input terminal of the second operational amplifier is connected to the second terminal of the inductor, and the second input terminal of the second operational amplifier is connected to the battery; A third operational amplifier, wherein the first input terminal of the third operational amplifier is connected to the input power supply, and the second input terminal of the third operational amplifier is connected to the system circuit; as well as A fourth operational amplifier, wherein the first input terminal of the fourth operational amplifier is connected to the battery, and the second input terminal of the fourth operational amplifier is connected to the second terminal of the inductor; A first selection circuit is connected to the output terminals of the third operational amplifier and the fourth operational amplifier, and is configured to select the signal output by one of the third operational amplifier and the fourth operational amplifier to output a first selection signal; A second selection circuit, connected to the output terminals of the first operational amplifier, the second operational amplifier, and the first selection circuit, is configured to select one of the signals output by the first operational amplifier, the second operational amplifier, and the first selection signal, to output a second selection signal; and A control circuit, connected to the second selection circuit and the switching circuit, is configured to control the operation of the switching circuit according to the second selection signal.

2. The switching charger for supplying stable power according to claim 1, characterized in that, The switching charger, which supplies stable power, also includes a voltage divider circuit, the input of which is connected to the battery, and the output of which is connected to the first input of the first operational amplifier.

3. The switching charger for supplying stable power according to claim 2, characterized in that, The voltage divider circuit includes: A first voltage divider resistor, the first end of which is connected to the battery; The second voltage divider resistor has its first end connected to the second end of the first voltage divider resistor and the first input terminal of the first operational amplifier, and its second end grounded.

4. The switching charger for supplying stable power according to claim 1, characterized in that, The switching circuit includes: An upper bridge switch, wherein the first terminal of the upper bridge switch is connected to the input power supply, and the control terminal of the upper bridge switch is connected to the control circuit; and A lower bridge switch is provided, with its first terminal connected to the second terminal of the upper bridge switch. The second terminal of the lower bridge switch is grounded. The node between the first terminal of the lower bridge switch and the second terminal of the upper bridge switch is connected to the first terminal of the inductor. The control terminal of the lower bridge switch is connected to the control circuit.

5. The switching charger for supplying stable power according to claim 4, characterized in that, The switching charger, which supplies stable power, also includes a NOT gate, the input of which is connected to the control circuit, and the output of which is connected to the control terminal of the lower bridge switch.

6. The switching charger for supplying stable power according to claim 1, characterized in that, The plurality of operational amplifiers further include: A fifth operational amplifier, wherein the first input terminal of the fifth operational amplifier is connected to the output terminal of the second operational amplifier, the second input terminal of the fifth operational amplifier is coupled to a second reference voltage, and the output terminal of the fifth operational amplifier is connected to the second selection circuit; The second selection circuit is configured to select one of the signals output by the first operational amplifier, the signals output by the fifth operational amplifier, and the first selection signal, in order to output the second selection signal.

7. The switching charger for supplying stable power according to claim 6, characterized in that, The plurality of operational amplifiers further include: A sixth operational amplifier, wherein the first input terminal of the sixth operational amplifier is connected to the output terminal of the third operational amplifier, the second input terminal of the sixth operational amplifier is coupled to a third reference voltage, and the output terminal of the sixth operational amplifier is connected to the first selection circuit; The first selection circuit is configured to select the signal output by one of the sixth operational amplifier and the fourth operational amplifier to output the first selection signal.

8. The switching charger for supplying stable power according to claim 7, characterized in that, The plurality of operational amplifiers further include: A seventh operational amplifier, wherein the first input terminal of the seventh operational amplifier is coupled to a fourth reference voltage, the second input terminal of the seventh operational amplifier is connected to the output terminal of the fourth operational amplifier, and the output terminal of the seventh operational amplifier is connected to the first selection circuit; The first selection circuit is configured to select the signal output by one of the sixth operational amplifier and the seventh operational amplifier to output the first selection signal.

9. The switching charger for supplying stable power according to claim 1, characterized in that, The switching charger, which supplies stable power, also includes: A sensing resistor, the first end of which is connected to the first input terminal of the second operational amplifier, the second input terminal of the fourth operational amplifier, and the second terminal of the inductor, and the second end of which is connected to the second input terminal of the second operational amplifier, the first input terminal of the fourth operational amplifier, and the battery.

10. The switching charger for supplying stable power according to claim 1, characterized in that, Also includes: An input resistor, the first end of which is connected to the input power supply and the first input terminal of the third operational amplifier, and the second end of which is connected to the second input terminal of the third operational amplifier, the switching circuit, and the system circuit.

11. The switching charger for supplying stable power according to claim 10, characterized in that, The switching charger, which supplies stable power, also includes: A first switching assembly, wherein a first end of the first switching assembly is connected to the input power supply; A second switching assembly, wherein a first terminal of the second switching assembly is connected to a second terminal of the first switching assembly, and a second terminal of the second switching assembly is connected to a first terminal of the input resistor; as well as A first switching circuit is connected to the control terminal of the first switching component and the control terminal of the second switching component, and is configured to switch the first switching component and the second switching component.

12. The switching charger for supplying stable power according to claim 8, characterized in that, The switching charger, which supplies stable power, also includes: An error amplifier is provided, wherein the first input terminal of the error amplifier is connected to the output terminal of the second selection circuit, the second input terminal of the error amplifier is coupled to the first reference voltage, and the output terminal of the error amplifier is connected to the input terminal of the control circuit.

13. The switching charger for supplying stable power according to claim 12, characterized in that, The switching charger, which supplies stable power, also includes: An eighth operational amplifier, wherein the first input terminal of the eighth operational amplifier is connected to the output terminal of the error amplifier, the second input terminal of the eighth operational amplifier is connected to the output terminal of an oscillation circuit, and the output terminal of the eighth operational amplifier is connected to the input terminal of the control circuit.

14. The switching charger for supplying stable power according to claim 12, characterized in that, The switching charger, which supplies stable power, also includes: A first resistor, the first end of which is connected to the output of the second selection circuit; A first capacitor, the first end of which is connected to the second end of the first resistor, and the second end of which is connected to the first input terminal of the error amplifier; as well as A second capacitor, the first end of which is connected to the first input terminal of the error amplifier, and the second end of which is connected to the output terminal of the error amplifier.

15. The switching charger for supplying stable power according to claim 14, characterized in that, The switching charger, which supplies stable power, also includes: The second resistor has its first end connected to the output terminal of the second selection circuit and its second end connected to the first input terminal of the error amplifier. A third resistor, the first end of which is connected to the first input terminal of the error amplifier; as well as A third capacitor, the first end of which is connected to the second end of the third resistor, and the second end of which is connected to the output terminal of the error amplifier.

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