Power management method, power adapter and controller thereof

Abstract

The invention relates to a power management method, a power adapter and a controller thereof. The method comprises the following steps: taking power from one auxiliary winding; cyclically executing a power supply management step: detecting the voltage output by the auxiliary winding of which the power is taken currently to obtain a power supply voltage; analyzing whether the power supply voltage is within a set threshold range or not; when the power supply voltage is within a set threshold range, taking power from the auxiliary winding which is taken power at present; when the power supply voltage is greater than the upper limit value of the set threshold range, taking power from one auxiliary winding of which the number of turns is smaller than that of the auxiliary winding of which the power is taken currently in the N auxiliary windings; and when the power supply voltage is smaller than the lower limit value of the set threshold range, taking power from one auxiliary winding of which the number of turns is larger than that of the auxiliary winding of which the power is taken currently in the N auxiliary windings. According to the invention, segmented power supply is realized when the output voltage range of the power adapter is relatively wide, and a BOOST circuit does not need to be additionally arranged.

Description

Technical Field

[0001] The present invention relates to the technical field of switching power supplies, and in particular to a power management method, a power adapter and a controller thereof. Background Art

[0002] With the popularity and application of mobile devices such as mobile phones, tablets, and power tools, people's demand for high-performance battery charging management chips has also increased significantly. Since the voltage application range of current mobile devices is very wide, in order to meet the wide voltage range application requirements of various mobile products on the market, the output voltage range of the adapter is also very wide. The voltage range reflected to the power supply end of the power management chip through the auxiliary winding of the transformer is also very wide, but this cannot be directly used for chip power supply. Therefore, the wide range output of the adapter poses new challenges to the power supply of the management chip of the power adapter.

[0003] Currently, if Figure 1 As shown in the figure, the power supply mode of the power management chip is: the turns ratio of the auxiliary winding is designed according to the maximum voltage value output by the adapter to correspond to the normal power supply voltage of the power management chip. When the voltage on the auxiliary winding meets the normal power supply voltage, the power supply voltage changes with the voltage VI N at the auxiliary winding end. When the output voltage of the adapter decreases and the voltage VI N at the auxiliary winding end drops to the threshold value, the power management chip starts the internal boost circuit, and the power supply voltage of the chip is provided by the voltage VI N at the auxiliary winding end after being boosted by the boost circuit. In this solution, the power supply voltage of the power management chip needs to be obtained indirectly, and the boost topology circuit needs to be integrated internally, and the boost inductor needs to be added externally, thereby increasing the circuit board area and cost. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a power management method, a power adapter and a controller thereof.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing a power management method for a controller in a power adapter, the power adapter also includes an energy storage component, the energy storage component includes a secondary winding for supplying power to a load and N auxiliary windings coupled to the secondary winding and having different numbers of turns, N being a natural number greater than 1, the power management method includes:

[0006] Taking power from one of the auxiliary windings;

[0007] The power supply management steps are executed cyclically, including: detecting the voltage output by the auxiliary winding currently powered to obtain the power supply voltage; analyzing whether the power supply voltage is within the set threshold range; when the power supply voltage is within the set threshold range, drawing power from the auxiliary winding currently powered; when the power supply voltage is greater than the upper limit value of the set threshold range, drawing power from an auxiliary winding among the N auxiliary windings whose number of turns is less than the auxiliary winding currently powered; when the power supply voltage is less than the lower limit value of the set threshold range, drawing power from an auxiliary winding among the N auxiliary windings whose number of turns is greater than the auxiliary winding currently powered.

[0008] Preferably, after determining to take power from one of the auxiliary windings, the method further comprises:

[0009] Dividing and detecting the supply voltage to obtain a feedback voltage signal capable of indicating the magnitude of the supply voltage, wherein the maximum value of the supply voltage and its voltage division ratio are positively correlated, so that the maximum value of the feedback voltage signal is not greater than a first set voltage value;

[0010] Current zero-crossing detection is performed according to the feedback voltage signal to obtain zero-crossing information that can indicate that the primary winding input current in the energy storage device has crossed zero.

[0011] Preferably, after determining to take power from one of the auxiliary windings, the method further comprises:

[0012] The output voltage of the secondary winding is determined according to the feedback voltage signal, the voltage division ratio, and the turns ratio between the auxiliary winding to be powered and the secondary winding.

[0013] Preferably, N is equal to 2; the power supply management step includes: detecting the voltage output by the auxiliary winding currently powered to obtain the power supply voltage; analyzing whether the power supply voltage is greater than the set threshold voltage; when the power supply voltage is greater than the set threshold voltage, drawing power from the auxiliary winding with fewer turns among the two auxiliary windings; when the power supply voltage is not greater than the set threshold voltage, drawing power from the auxiliary winding with more turns among the two auxiliary windings.

[0014] The present invention also constructs a controller for a power adapter, the power adapter comprising an energy storage device, the energy storage device comprising a secondary winding and N auxiliary windings coupled to the secondary winding and having the same winding direction and different numbers of turns, N being a natural number greater than 1, the controller comprising:

[0015] A power-taking switch unit, used for taking power from one of the N auxiliary windings;

[0016] A signal detection unit, used to detect the voltage output by the auxiliary winding currently powered to obtain the supply voltage;

[0017] A winding selection unit is used to analyze whether the supply voltage is within a set threshold range, and control the operation of the power switching unit according to the analysis result, including: when the supply voltage is within the set threshold range, drawing power from the auxiliary winding currently being powered; when the supply voltage is greater than the upper limit value of the set threshold range, drawing power from an auxiliary winding among the N auxiliary windings whose number of turns is less than the auxiliary winding currently being powered; when the supply voltage is less than the lower limit value of the set threshold range, drawing power from an auxiliary winding among the N auxiliary windings whose number of turns is greater than the auxiliary winding currently being powered.

[0018] Preferably, the signal detection unit comprises:

[0019] A voltage detection unit, used to divide and detect the supply voltage to obtain a feedback voltage signal that can represent the magnitude of the supply voltage; wherein the maximum value of the supply voltage and its voltage division ratio are positively correlated, so that the maximum value of the feedback voltage signal is not greater than a first set voltage value;

[0020] The current zero-crossing detection unit is used to perform current zero-crossing detection according to the feedback voltage signal to obtain zero-crossing information that can indicate that the primary winding input current in the energy storage device has crossed zero.

[0021] Preferably, the controller further comprises a low voltage power supply pin VCC and a plurality of high voltage power supply pins VCCH;

[0022] The power switch unit is connected to the auxiliary winding with the least number of turns among the N auxiliary windings through the low-voltage power supply pin VCC, and the power switch unit is connected to the remaining auxiliary windings among the N auxiliary windings except the auxiliary winding with the least number of turns through the plurality of high-voltage power supply pins VCCH one by one;

[0023] The winding selection unit is also used to control the power switch unit to disconnect the connection between the auxiliary winding with the least turns and other auxiliary windings during initial power-on, so as to draw power from the auxiliary winding with the least turns; and, when power is required for an auxiliary winding other than the auxiliary winding with the least turns, the power switch unit is controlled to connect the connection between the auxiliary winding with the least turns and the auxiliary winding, so as to draw power from the auxiliary winding.

[0024] Preferably, N is equal to 2, the two auxiliary windings constitute an integrated winding, the same-name ends of the two auxiliary windings are connected, and a tap is provided at the connection of the same-name ends.

[0025] Preferably, the voltage detection unit comprises:

[0026] a low voltage detection unit connected to the auxiliary winding with fewer turns, and configured to divide and detect the output voltage of the auxiliary winding with fewer turns when taking power from the auxiliary winding with fewer turns, so as to obtain the feedback voltage signal;

[0027] A plurality of voltage dividing units with different voltage dividing ratios, wherein the plurality of voltage dividing units are respectively connected to the auxiliary winding with more turns, and each of the voltage dividing units is used to divide the output voltage of the auxiliary winding with more turns at a corresponding voltage dividing ratio to obtain a plurality of divided signals;

[0028] A selection unit is connected to the multiple voltage-dividing units and is used to select a voltage-divided signal output by one of the voltage-dividing units as the feedback voltage signal according to the output voltage of the auxiliary winding with more turns when drawing power from the auxiliary winding with more turns; wherein the maximum output voltage of the auxiliary winding with more turns is positively correlated with the voltage-dividing ratio of the selected voltage-dividing unit, so that the maximum value of the feedback voltage signal is not greater than the first set voltage value.

[0029] The present invention also constructs a power adapter, including an energy storage component and the controller as described above;

[0030] The energy storage device includes a secondary winding and N auxiliary windings coupled to the secondary winding and having the same winding direction and different numbers of turns.

[0031] The implementation of the present invention has the following beneficial effects: a power management method is provided, which realizes segmented power supply when the output voltage range of the power adapter is wide by selecting a suitable auxiliary winding for power supply according to the output voltage of the power adapter, without the need for additional BOOST circuits, saving circuit board area and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0033] Figure 1 It is a circuit schematic diagram of a power adapter in the related art;

[0034] Figure 2 is a flowchart of a power management method in some embodiments of the present invention;

[0035] Figure 3 It is a waveform diagram of the drain and gate voltage changes of the power switch tube, the current changes of the primary winding and the power supply voltage in some embodiments of the present invention;

[0036] Figure 4 is a circuit schematic diagram of a power adapter in some embodiments of the present invention;

[0037] Figure 5is a circuit schematic diagram of a winding selection unit in some embodiments of the present invention;

[0038] Figure 6 is a circuit schematic diagram of a signal detection unit in some embodiments of the present invention;

[0039] Figure 7 It is a circuit schematic diagram of a power taking switch unit in some embodiments of the present invention. DETAILED DESCRIPTION

[0040] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0041] It should be noted that the flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor do they have to be executed in the order described. For example, some operations / steps can be decomposed, while some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0042] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0043] The present invention provides a power management method, which is used for a controller in a power adapter. By selecting a suitable auxiliary winding for power supply according to the output voltage of the power adapter, segmented power supply is realized when the output voltage range of the power adapter is wide, without adding an additional BOOST circuit, thus saving circuit board area and cost. Figure 4 The power adapter includes a controller 10, a power switch tube 20, and an energy storage device 60, wherein the energy storage device 60 includes a primary winding 63 that draws power from an input power source (such as a mains), a secondary winding 64 that supplies power to a load, and N auxiliary windings (the N auxiliary windings include a winding 61 and a winding 62) coupled to the secondary winding 64 and having different numbers of turns, where N is a natural number greater than 1. In addition, each load winding forms a forward structure with the secondary winding 64, that is, the ratio of the output voltage of each load winding to the output voltage of the secondary winding 64 is equal to the turns ratio of the load winding to the secondary winding 64.

[0044] like Figure 2 As shown, the power management method may include step S10 and step S20.

[0045] Step S10 includes: taking power from one of the auxiliary windings. Figure 4, the controller 10, the power switch tube 20 and the energy storage element 60 form a typical switching power supply circuit, and its working principle can refer to the prior art and will not be described here. At the initial power-on, the input power will charge the capacitor 80 through the resistor 70. When the capacitor 80 is charged to the starting voltage of the controller 10, the controller 10 starts and starts to control the power switch tube 20 to work, that is, the switching power supply circuit starts to work. In theory, power can be taken from any auxiliary winding at this time. In order to ensure that the controller 10 is not damaged due to overvoltage of the power supply voltage, the auxiliary winding with the smallest number of turns can be used for power at the initial power-on. Since the output voltage of the secondary winding 64 is proportional to the output voltage of each auxiliary winding, considering that when the output voltage of the secondary winding 64 is small, the output voltage of the auxiliary winding with the smallest number of turns may not be able to drive the controller 10 normally, then at the time of initial power-on, the auxiliary winding with the middle number of turns among the N auxiliary windings can be selected to draw power. For example, when N is equal to 3, the auxiliary winding with neither the smallest nor the largest number of turns can be selected to draw power. For example, when N is equal to 4, the auxiliary winding with the second or third number of turns among the four auxiliary windings arranged in ascending order can be selected to draw power.

[0046] Step S20 includes: executing the power supply management step cyclically, including: detecting the voltage output by the auxiliary winding currently powered on to obtain the power supply voltage; analyzing whether the power supply voltage is within the set threshold range; when the power supply voltage is within the set threshold range, power is taken from the auxiliary winding currently powered on; when the power supply voltage is greater than the upper limit of the set threshold range, power is taken from an auxiliary winding with a smaller number of turns than the auxiliary winding currently powered on among the N auxiliary windings; when the power supply voltage is less than the lower limit of the set threshold range, power is taken from an auxiliary winding with a larger number of turns than the auxiliary winding currently powered on among the N auxiliary windings. In this step, the power supply voltage required by the controllers in different application scenarios is different. For example, the operating voltage of the controller L6562DTR produced by STMicroelectronics is 10.3 to 22 volts, and the power supply voltage of the controller UC3843BD1 R2G produced by ON Semiconductor is 7.6 to 30 volts. Therefore, the threshold range can be customized according to the actual application or requirements of the controller, and is not limited here.

[0047] To avoid the risk of overvoltage in the embedded circuit of the controller, the controller usually uses a weak current signal (i.e., a voltage signal not greater than 5V) to achieve control during the execution of software control. However, since the output voltage of the secondary winding is proportional to the output voltage of each auxiliary winding, when the output voltage of the secondary winding is larger, the output voltage of the auxiliary winding will also increase accordingly. In this regard, in some embodiments, the power management method may also include: after determining to take power from one of the auxiliary windings, executing steps SS201 and SS202.

[0048] Step SS201 includes: dividing and detecting the supply voltage to obtain a feedback voltage signal that can represent the magnitude of the supply voltage, wherein the maximum value of the supply voltage and its voltage division ratio are positively correlated so that the maximum value of the feedback voltage signal is not greater than the first set voltage value.

[0049] In this step, the power supply voltage is first divided by a certain voltage division ratio to obtain a voltage division voltage (the voltage division voltage is equal to the power supply voltage divided by the voltage division ratio), and then the magnitude of the voltage division voltage is detected. If the voltage division voltage is not greater than the first set voltage value (such as 3.3V), the voltage division voltage can be determined as the feedback voltage signal. If the voltage division voltage is greater than the first set voltage value, the power supply voltage will be divided by a larger voltage division ratio until the obtained voltage division voltage is not greater than the first set voltage value, and the voltage division voltage at this time is defined as the feedback voltage signal. In order to avoid the reduction in the accuracy of the subsequent circuit that obtains the feedback voltage signal to restore the power supply voltage size using the feedback voltage signal due to the small voltage value of the feedback voltage signal, when the voltage division voltage is less than the second set voltage value (such as 1V), the power supply voltage will be divided by a smaller voltage division ratio until the obtained voltage division voltage is not less than the second set voltage value. It can be understood that by implementing this embodiment, the feedback voltage signal can be maintained between the second set voltage value and the first set voltage value, which can not only avoid overvoltage damage to the subsequent circuit that obtains the feedback voltage signal, but also improve the accuracy of the feedback voltage signal.

[0050] It should be noted that, in this step, the supply voltage can be divided by a voltage divider circuit provided in the controller, wherein the voltage divider circuit can be composed of a plurality of resistors connected in series.

[0051] Step SS202 includes: performing current zero-crossing detection according to the feedback voltage signal to obtain zero-crossing information that can indicate that the primary winding input current in the energy storage device has crossed zero.

[0052] In this step, since the feedback voltage signal can represent the power supply voltage, the change of the power supply voltage can also be known by monitoring the change of the feedback voltage signal. Figure 4 , and because the auxiliary winding (winding 61 or winding 62) that provides the power supply voltage and the primary winding 63 form a flyback structure, after the power switch tube 20 is turned off, the primary winding 63 will transfer energy to the auxiliary winding by electromagnetic coupling. Therefore, when the power supply voltage is known, the zero-crossing moment (i.e., zero-crossing information) of the inductor current of the primary winding 63 can be determined by analyzing the change of the power supply voltage. Please refer to Figure 3 The moment when the power supply voltage (ie, VCC / VCCH) starts to drop from a stable voltage can be determined as the moment when the inductor current of the primary winding 63 passes through zero.

[0053] like Figure 4As shown, the traditional solution for obtaining the output voltage of the secondary winding is to determine the output voltage of the secondary winding through the voltage value of the voltage feedback pin FB of the controller, the voltage divider circuit 50 and the turns ratio of the secondary winding to the load winding. However, this will consume an extra chip pin (pin FB). In view of this, in some embodiments, the power management method may also include: after determining to take power from one of the auxiliary windings (i.e., after executing step SS202), executing step SS203.

[0054] Step SS203 includes: determining the output voltage of the secondary winding according to the feedback voltage signal, the voltage division ratio and the turns ratio of the auxiliary winding to be powered and the secondary winding. In this step, for the voltage division ratio, since the selected voltage division circuit is pre-set inside the controller in the execution of step SS201, and the voltage division ratio of the voltage division circuit configured inside the controller can be agreed and recorded in advance, after determining the feedback voltage signal, the voltage division ratio of the voltage division circuit that actually divides the power supply voltage can be obtained. For the turns ratio of the auxiliary winding to the secondary winding, it can be determined by pre-storing, so as to obtain the voltage division ratio of the voltage division circuit that actually divides the power supply voltage. Figure 4 For example, firstly, the turns ratios A1 and A2 are pre-stored in the controller, and then the turns ratio of the auxiliary winding 61 to the secondary winding 64 is configured as A1, and the turns ratio of the auxiliary winding 62 to the secondary winding 64 is configured as A2. Then, when the controller draws power from the auxiliary winding 61, the turns ratio can be determined to be A1, and when the controller draws power from the auxiliary winding 62, the turns ratio can be determined to be A2. Considering that some users will fine-tune or even significantly adjust the turns ratio of the auxiliary winding to the secondary winding according to actual application requirements, the pre-stored solution lacks flexibility, so the actual turns ratio of each auxiliary winding to the secondary winding can also be entered by burning, communication (such as serial communication), etc.

[0055] In some embodiments, N can be equal to 2, and accordingly, the power supply management step may include: detecting the voltage output by the auxiliary winding currently powered to obtain the power supply voltage; analyzing whether the power supply voltage is greater than a set threshold voltage; when the power supply voltage is greater than the set threshold voltage, drawing power from the auxiliary winding with fewer turns of the two auxiliary windings; when the power supply voltage is not greater than the set threshold voltage, drawing power from the auxiliary winding with more turns of the two auxiliary windings.

[0056] like Figure 4As shown, the present invention also provides a controller 10 for a power adapter, the power adapter includes a power switch tube 20 and an energy storage device 60, wherein the energy storage device 60 includes a primary winding 63 that draws power from an input power source (such as a mains), a secondary winding 64 that supplies power to a load, and N auxiliary windings (the N auxiliary windings include winding 61 and winding 62) coupled to the secondary winding 64 and having different numbers of turns, where N is a natural number greater than 1. Further, the controller 10 may include a winding selection unit 11, a power switch unit 12, a signal detection unit 13, and a processing unit 14.

[0057] See also Figure 4 The power-taking switch unit 12 is connected to each auxiliary winding to take power from one of the N auxiliary windings.

[0058] See also Figure 4 The signal detection unit 13 is connected to each auxiliary winding to detect the voltage output by the auxiliary winding currently powered to obtain the supply voltage.

[0059] In some embodiments, Figure 5 and Figure 6 As shown, the signal detection unit 13 may include a voltage detection unit 131 and a current zero-crossing detection unit 132. The voltage detection unit 131 is connected to the processing unit 14 and each auxiliary winding to divide and detect the supply voltage, obtain a feedback voltage signal that can represent the magnitude of the supply voltage, and input the feedback voltage signal to the processing unit 14; wherein the maximum value of the supply voltage and its voltage division ratio are positively correlated, so that the maximum value of the feedback voltage signal is not greater than the first set voltage value. The current zero-crossing detection unit 132 is connected to the processing unit 14 and the voltage detection unit 131 to perform current zero-crossing detection according to the feedback voltage signal, so as to obtain zero-crossing information that can represent the zero-crossing of the input current of the primary winding in the energy storage device, and input the zero-crossing information to the processing unit 14.

[0060] See also Figure 4 The winding selection unit 11 is connected to the power switch unit 12 and the signal detection unit 13, and is used to analyze whether the power supply voltage is within the set threshold range, and control the power switch unit 12 to work according to the analysis result, including: when the power supply voltage is within the set threshold range, power is taken from the auxiliary winding currently being powered; when the power supply voltage is greater than the upper limit value of the set threshold range, power is taken from an auxiliary winding among the N auxiliary windings whose number of turns is less than the auxiliary winding currently being powered; when the power supply voltage is less than the lower limit value of the set threshold range, power is taken from an auxiliary winding among the N auxiliary windings whose number of turns is greater than the auxiliary winding currently being powered.

[0061] In some embodiments, the controller further includes a low-voltage power supply pin VCC and several high-voltage power supply pins VCCH. The power switch unit 12 is connected to the auxiliary winding with the least number of turns among the N auxiliary windings through the low-voltage power supply pin VCC, and the power switch unit 12 is connected to the remaining auxiliary windings except the auxiliary winding with the least number of turns among the N auxiliary windings through several high-voltage power supply pins VCCH one-to-one. The winding selection unit 11 is also used to disconnect the connection between the auxiliary winding with the least number of turns and other auxiliary windings at the time of initial power-on by controlling the power switch unit 12 to draw power from the auxiliary winding with the least number of turns, and, when power is required for an auxiliary winding other than the auxiliary winding with the least number of turns, the power switch unit 12 is controlled to connect the connection between the auxiliary winding with the least number of turns and the auxiliary winding (i.e., the above-mentioned auxiliary winding) to draw power from the auxiliary winding.

[0062] In some embodiments, Figure 4 As shown, N can be equal to 2, two auxiliary windings (including winding 61 and winding 62) form an integrated winding, the same-name ends of the two auxiliary windings are connected, and a tap is provided at the connection of the same-name ends, and the tap is connected to the ground, which helps to simplify the winding process of the two auxiliary windings and helps to reduce the volume and cost of the energy storage component 60. Accordingly, in this embodiment, the number of high-voltage power supply pins VCCH is 1.

[0063] In such Figure 4 In the embodiment shown, see Figure 7 The power switch unit 12 may include an NMOS tube 120, a constant current source 121, a resistor 122, a voltage regulator tube 123, a first PMOS tube 124, and a second PMOS tube 125. The gate of the NMOS tube 120 is connected to the winding selection unit 11, the source of the NMOS tube 120 is connected to the ground through the constant current source 121, the drain is simultaneously connected to the second end of the resistor 122, the anode of the voltage regulator tube 123, and the gate of the first PMOS tube 124, the source of the first PMOS tube 124 is connected to the low-voltage power supply pin VCC and the winding selection unit 11, the drain is connected to the high-voltage power supply pin VCCH through the drain and source of the second PMOS tube 125, the drain of the second PMOS tube 125 is also connected to the first end of the resistor 122 and the cathode of the voltage regulator tube 123, and the source of the second PMOS tube 125 is grounded.

[0064] In this embodiment, the working principle of the power switch unit 12 is as follows: Figure 4 and Figure 7When the winding selection unit 11 detects that the power supply voltage output by the auxiliary winding 61 connected to the low-voltage power supply pin VCC is not greater than the set threshold voltage, the winding selection unit 11 outputs a high level to the gate of the NMOS tube 120 to control the NMOS tube 120 to be turned on, so that the gate of the first PMOS tube 124 is set to a low level. When the auxiliary winding 62 connected to the high-voltage power supply pin VCCH has an output voltage, the second PMOS tube 125 is turned on, so the first PMOS tube 124 is turned on, that is, the high-voltage power supply pin VCCH is connected to the low-voltage power supply pin VCC through the second PMOS tube 125 and the first PMOS tube 124. Since the number of turns of the auxiliary winding 62 is greater than that of the auxiliary winding 61, the output voltage of the auxiliary winding 62 is greater than the output voltage of the auxiliary winding 61, then the low-voltage power supply pin VCC will draw power from the auxiliary winding 62 through the power-taking switch unit 12. It can be understood that when the winding selection unit 11 detects that the power supply voltage output by the auxiliary winding 61 connected to the low-voltage power supply pin VCC is greater than the set threshold voltage, the winding selection unit 11 outputs a low level to the gate of the NMOS tube 120, so that the NMOS tube 120 is turned off, and finally the first PMOS tube 124 is turned off, so that the low-voltage power supply pin VCC will draw power from the auxiliary winding 61. In addition, the function of the constant current source 121 is to limit the current flowing into the drain of the NMOS tube 120 when it is turned on, so that the current shunted to the drain of the NMOS tube 120 when the NMOS tube 120 is turned on is small, so that the current input to the source of the first PMOS tube 124 is large enough, thereby ensuring that the current input from the auxiliary winding 62 to the low-voltage power supply pin VCC is sufficient to drive the controller 10 to operate normally. The function of the voltage regulator 123 is to ensure that the voltage difference between the source and the gate of the first PMOS tube 124 is not less than the voltage regulation value of the voltage regulator 123 when the drain of the NMOS tube 120 is turned off, thereby ensuring that the first PMOS tube 124 is in the turned-off state.

[0065] In some embodiments, Figure 5 and Figure 6 As shown, the voltage detection unit 131 may include a low voltage detection unit 1311, a selection unit 1314, and a plurality of voltage division units 1312 with different voltage division ratios.

[0066] See also Figure 4 and Figure 5 The low voltage detection unit 1311 is connected to the auxiliary winding with fewer turns through the low voltage power supply pin VCC, so that when the power is taken from the auxiliary winding with fewer turns, the output voltage of the auxiliary winding with fewer turns is divided and detected to obtain the feedback voltage signal corresponding to the auxiliary winding with fewer turns. The low voltage detection unit 1311 is also connected to the processing unit 14 to input the feedback voltage signal thereto. Among them, the low voltage detection unit 1311 can be a voltage divider circuit composed of multiple resistors connected in series.

[0067] See also Figure 4 and Figure 6 , multiple voltage dividing units 1312 are connected one-to-one to the auxiliary winding with more turns through the high-voltage power supply pin VCCH, and each voltage dividing unit 1312 is used to divide the output voltage of the auxiliary winding with more turns at a corresponding voltage dividing ratio to obtain multiple divided signals.

[0068] In such Figure 4 In the embodiment shown, see Figure 6 , each voltage-dividing unit 1312 may include a resistor 3121, a resistor 3122, a resistor 3123 and a voltage-stabilizing tube 3124. The first end of the resistor 3121 is connected to the high-voltage power supply pin VCCH, and the second end is connected to the ground through the resistor 3122 and the resistor 3123. The anode of the voltage-stabilizing tube 3124 is grounded, and the cathode is connected to the second end of the resistor 3121. The resistors 3121, 3122, and 3123 form a voltage-dividing voltage, wherein the second end of the resistor 3121 is connected to the selection unit 1314 to input a first voltage-dividing signal to the selection unit 1314, and the connection point between the resistor 3122 and the resistor 3123 is connected to the current zero-crossing detection unit 132 to input a second voltage-dividing signal to the selection unit 1314. The function of the voltage-stabilizing tube 3124 is to clamp the first voltage-dividing signal, so as to prevent the selection unit 1314 from being damaged due to the excessive voltage value of the first voltage-dividing signal.

[0069] It should be noted that Figure 6 The two voltage dividing units 1312 are included, and the circuit structures of the two are the same. The difference is that the voltage dividing ratios of the voltage dividing circuits composed of the resistors 3121, 3122 and 3123 respectively included in the two are different.

[0070] See also Figure 6 The selection unit 1314 is connected to the processing unit 14 and multiple voltage dividing units 1312, and is used to select a voltage-divided signal output by one of the voltage dividing units 1312 as a feedback voltage signal according to the output voltage of the auxiliary winding with more turns when drawing power from the auxiliary winding with more turns; wherein the maximum output voltage of the auxiliary winding with more turns is positively correlated with the voltage dividing ratio of the selected voltage dividing unit 1312, so that the maximum value of the feedback voltage signal is not greater than the first set voltage value.

[0071] In such Figure 4 In the embodiment shown, the number of the voltage dividing units 1312 is 2. Figure 6, the selection unit 1314 may include a first high voltage detection unit 3141, a first two-selection unit 3143, and a second high voltage detection unit 3142. The first end of the first high voltage detection unit 3141 is connected to the second end of the resistor 3121 included in one of the voltage divider units 1312, and the second end is connected to the first two-selection unit 3143, the first end of the second high voltage detection unit 3142 is connected to the second end of the resistor 3121 included in another voltage divider unit 1312, and the second end is connected to the first two-selection unit 3143, and the first two-selection unit 3143 is also connected to the winding selection unit 11 and the processing unit 14. Among them, the first high voltage detection unit 3141 and the second high voltage detection unit 3142 can be existing ADC circuits, which can convert the collected first voltage division signal into a digital signal and send the digital signal to the first two-selection unit 3143. After receiving the digital signals from the first and second high voltage detection units, the first two-selection unit 3143 selects the digital signal converted from the first voltage-divided signal within the first set voltage range according to the magnitude of the two first voltage-divided signals and sends it to the processing unit 14. The winding selection unit 11 outputs the enable signal N102 according to whether the winding actually selected is selected. When the winding selection unit 11 selects to take power from the auxiliary winding with more turns (corresponding to controlling the NMOS tube 120 to be turned on), the enable signal N102 will be output. The first two-selection unit 3143 will be enabled and work normally only when it receives the enable signal N102, otherwise the two-selection work will be suspended.

[0072] exist Figure 4 In the embodiment shown, see Figure 6The current zero-crossing detection unit 132 may include a first ZCD detection unit 1321, a second two-choice unit 1323, and a second ZCD detection unit 1322. The first end of the first ZCD detection unit 1321 is connected to a connection point between a resistor 3122 and a resistor 3123 included in one of the voltage divider units 1312, and the second end is connected to the second two-choice unit 1323. The first end of the second ZCD detection unit 1322 is connected to a connection point between a resistor 3122 and a resistor 3123 included in another voltage divider unit 1312, and the second end is connected to the second two-choice unit 1323. The second two-choice unit 1323 is also connected to the winding selection unit 11 and the processing unit 14. Among them, since the voltage division ratios of the two voltage division units 1312 are different, the voltage values ​​of the second voltage division signals output by the two are also different, and the voltage value change amplitude of the second voltage division signal will affect the detection accuracy of the first ZCD detection unit 1321 and the second ZCD detection unit 1322. For example, when the voltage of the second voltage division signal is large, there is a risk of advancing the zero crossing detection time, and when the voltage of the second voltage division signal is small, there is a risk of reduced zero crossing detection accuracy. Therefore, the information obtained by performing zero crossing detection on the voltage value of the second voltage division signal within an appropriate range is preferentially taken as the zero crossing information finally input to the processing unit 14, and the first ZCD detection unit 1321 and the second ZCD detection unit 1322 can also detect the voltage value of the corresponding second voltage division signal when performing zero crossing detection to determine whether it is within the second set voltage range, and send the determination result to the second two-selection unit 1323, so that the second two-selection unit 1323 can select appropriate information as the final zero crossing information according to the determination result, so as to input the zero crossing information into the processing unit 14. In addition, the first ZCD detection unit 1321 and the second ZCD detection unit 1322 can be respectively composed of existing zero-crossing detection circuits. The second two-choice unit 1323 is enabled and works normally only when receiving the enable signal N102, otherwise the two-choice work is suspended.

[0073] exist Figure 4 In the embodiment shown, see Figure 5, the winding selection unit 11 may include a comparator 111 and a delay unit 112. One input end of the comparator 111 is connected to the low voltage detection unit 1311 to receive the feedback voltage signal output by the low voltage detection unit 1311, the other input end is connected to the processing unit 14 to obtain the reference signal output by the processing unit 14, and the output end is connected to the delay unit 112. The delay unit 112 is connected to the power switch unit 12 and the signal detection unit 13. The comparator 111 compares the obtained feedback voltage signal with the reference signal and outputs the comparison result (high level or low level) to the delay unit 112. After the delay unit 112 delays the comparison result, it inputs the first sub-comparison result N101 to the power switch unit 12 and the second sub-comparison result N102 to the signal detection unit 13. Among them, the delay unit 112 can be an existing delay circuit, which is used to delay the comparison result, so as to prevent the power switch unit 12 and the signal detection unit 13 from jittering, thereby improving the stability of the controller 10.

[0074] It should be noted that in Figure 4 In the illustrated embodiment, when the power taking switch unit 12 is turned on, that is, when power is taken from the auxiliary winding 62, the output voltage of the auxiliary winding 62 can enter the winding selection unit 11 through the power taking switch unit 12, so the comparator 111 can also be used for signal comparison. When the output voltage of the auxiliary winding 62 is greater than the set threshold voltage, the comparison result of the comparator 111 can control the switch to take power from the auxiliary winding 61.

[0075] It should be noted that the processing unit 14 is the main control circuit module in the controller 10 responsible for controlling the operation of the switching power supply, including outputting the drive signal of the power switch tube 20, executing overvoltage protection, executing undervoltage protection, executing over-temperature protection, etc. For details, please refer to the existing technology and will not be repeated here.

[0076] See also Figure 4 The present invention also constructs a power adapter, including a power switch tube 20, an energy storage device 60 and a controller provided by an embodiment of the present invention. The energy storage device 60 includes a primary winding 63, a secondary winding 64 and N auxiliary windings coupled to the secondary winding and having the same winding direction and different numbers of turns.

[0077] exist Figure 4In the illustrated embodiment, the power adapter may further include a rectifying and unidirectional conduction circuit 30 and a rectifying circuit 40. The rectifying and unidirectional conduction circuit 30 is connected in series between the auxiliary winding 61 and the low voltage power supply pin VCC. The rectifying and unidirectional conduction circuit 30 rectifies the voltage input to the low voltage power supply pin VCC on the one hand, and prevents the output voltage of the auxiliary winding 62 from being input to the auxiliary winding 61 when the power switch unit 12 is turned on on the other hand. The rectifying circuit 40 is connected in series between the auxiliary winding 62 and the high voltage power supply pin VCCH to rectify the voltage input to the high voltage power supply pin VCCH.

[0078] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0079] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0080] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0081] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A power management method, used in a controller in a power adapter, wherein the power adapter also includes an energy storage device, wherein the energy storage device includes a secondary winding for supplying power to a load and N auxiliary windings coupled to the secondary winding and having different numbers of turns, wherein N is a natural number greater than 1, characterized in that: The power management method comprises: Taking power from one of the auxiliary windings; The power supply management steps are executed cyclically, including: detecting the voltage output by the auxiliary winding currently powered to obtain the power supply voltage; analyzing whether the power supply voltage is within the set threshold range; when the power supply voltage is within the set threshold range, drawing power from the auxiliary winding currently powered; when the power supply voltage is greater than the upper limit value of the set threshold range, drawing power from an auxiliary winding among the N auxiliary windings whose number of turns is less than the auxiliary winding currently powered; when the power supply voltage is less than the lower limit value of the set threshold range, drawing power from an auxiliary winding among the N auxiliary windings whose number of turns is greater than the auxiliary winding currently powered.

2. The power management method according to claim 1, characterized in that: After determining to take power from one of the auxiliary windings, the method further includes: Dividing and detecting the supply voltage to obtain a feedback voltage signal capable of indicating the magnitude of the supply voltage, wherein the maximum value of the supply voltage and its voltage division ratio are positively correlated, so that the maximum value of the feedback voltage signal is not greater than a first set voltage value; Current zero-crossing detection is performed according to the feedback voltage signal to obtain zero-crossing information that can indicate that the primary winding input current in the energy storage device has crossed zero.

3. The power management method according to claim 2, characterized in that: After determining to take power from one of the auxiliary windings, the method further includes: The output voltage of the secondary winding is determined according to the feedback voltage signal, the voltage division ratio, and the turns ratio between the auxiliary winding to be powered and the secondary winding.

4. The power management method according to any one of claims 1 to 3, characterized in that: Said N is equal to 2; The power supply management step includes: detecting the voltage output by the auxiliary winding currently powered to obtain the power supply voltage; analyzing whether the power supply voltage is greater than a set threshold voltage; when the power supply voltage is greater than the set threshold voltage, drawing power from the auxiliary winding with fewer turns among the two auxiliary windings; when the power supply voltage is not greater than the set threshold voltage, drawing power from the auxiliary winding with more turns among the two auxiliary windings.

5. A controller for a power adapter, the power adapter comprising an energy storage component, characterized in that: The energy storage device includes a secondary winding and N auxiliary windings coupled to the secondary winding and having the same winding direction and different numbers of turns, where N is a natural number greater than 1, and the controller includes: A power-taking switch unit (12), used for taking power from one of the N auxiliary windings; A signal detection unit (13) is used to detect the voltage output by the auxiliary winding currently powered to obtain a supply voltage; A winding selection unit (11) is used to analyze whether the power supply voltage is within a set threshold range, and control the operation of the power supply switch unit (12) according to the analysis result, including: when the power supply voltage is within the set threshold range, power is taken from the auxiliary winding currently being powered; when the power supply voltage is greater than the upper limit value of the set threshold range, power is taken from an auxiliary winding among the N auxiliary windings whose number of turns is less than the auxiliary winding currently being powered; when the power supply voltage is less than the lower limit value of the set threshold range, power is taken from an auxiliary winding among the N auxiliary windings whose number of turns is greater than the auxiliary winding currently being powered.

6. The controller according to claim 5, characterized in that: The signal detection unit (13) comprises: A voltage detection unit (131) is used to divide and detect the supply voltage to obtain a feedback voltage signal that can represent the magnitude of the supply voltage; wherein the maximum value of the supply voltage and its voltage division ratio are positively correlated, so that the maximum value of the feedback voltage signal is not greater than a first set voltage value; A current zero-crossing detection unit (132) is used to perform current zero-crossing detection according to the feedback voltage signal to obtain zero-crossing information that can indicate that the primary winding input current in the energy storage device has crossed zero.

7. The controller according to claim 6, characterized in that: The controller also includes a low voltage power supply pin VCC and a plurality of high voltage power supply pins VCCH; The power switch unit (12) is connected to the auxiliary winding with the least number of turns among the N auxiliary windings through the low-voltage power supply pin VCC, and the power switch unit (12) is connected one-to-one to the remaining auxiliary windings among the N auxiliary windings except the auxiliary winding with the least number of turns through the plurality of high-voltage power supply pins VCCH; The winding selection unit (11) is also used to disconnect the connection between the auxiliary winding with the least turns and other auxiliary windings by controlling the power-taking switch unit (12) during initial power-on, so as to draw power from the auxiliary winding with the least turns; and, when power is required to be supplied to an auxiliary winding other than the auxiliary winding with the least turns, connect the connection between the auxiliary winding with the least turns and the auxiliary winding by controlling the power-taking switch unit (12) to draw power from the auxiliary winding.

8. The controller according to claim 6 or 7, characterized in that: The N is equal to 2, the two auxiliary windings form an integrated winding, the same-name ends of the two auxiliary windings are connected, and a tap is provided at the connection of the same-name ends.

9. The controller according to claim 8, characterized in that: The voltage detection unit (131) comprises: A low voltage detection unit (1311) is connected to the auxiliary winding with fewer turns, and is used to divide and detect the output voltage of the auxiliary winding with fewer turns when taking power from the auxiliary winding with fewer turns, so as to obtain the feedback voltage signal; A plurality of voltage dividing units (1312) having different voltage dividing ratios, the plurality of voltage dividing units (1312) being respectively connected to auxiliary windings having a large number of turns, and each of the voltage dividing units (1312) being used to divide the output voltage of the auxiliary windings having a large number of turns at a corresponding voltage dividing ratio to obtain a plurality of divided signals; A selection unit (1314) is connected to the multiple voltage dividing units (1312) and is used to select a voltage-divided signal output by one of the voltage dividing units (1312) as the feedback voltage signal according to the output voltage of the auxiliary winding with more turns when drawing power from the auxiliary winding with more turns; wherein the maximum output voltage of the auxiliary winding with more turns is positively correlated with the voltage dividing ratio of the selected voltage dividing unit (1312), so that the maximum value of the feedback voltage signal is not greater than the first set voltage value.

10. A power adapter, characterized in that: A controller comprising an energy storage device and any one of claims 5 to 9; The energy storage device includes a secondary winding and N auxiliary windings coupled to the secondary winding and having the same winding direction and different numbers of turns.

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