Power supply and method for saving power consumption thereof

Abstract

The present invention provides a power supply and a method for saving power consumption, wherein the method can include: using a monitoring circuit in the power supply to generate a monitoring signal according to the operating load of the power supply; and using a control signal generating circuit in the power supply to generate a control signal according to the monitoring signal, to drive at least two switching transistors in a circuit in the power supply, wherein the switching transistors are in parallel. The present invention can effectively reduce the power consumption of the whole system under very light load, by reducing the voltage level used to drive the switching transistors or controlling the number of enabled switching transistors.

Description

Technical Field

[0001] This invention relates to a power-saving method for a central processing unit, and more particularly to a power supply and a method for saving power consumption thereon. Background Technology

[0002] A power supply is used to convert AC power into DC power and provide driving voltage for electronic devices. The lower the power supply's power consumption under very light loads, the better its efficiency and the more energy it can save.

[0003] With advancements in semiconductor manufacturing technology, chip manufacturers (such as central processing units) are continuously striving to improve the efficiency of power supply output power. On the other hand, due to increasing energy shortages and global warming, energy-saving regulations are becoming increasingly stringent, such as the Intel Guidelines' requirements for power supply efficiency under extremely light loads. For instance, the Intel Guidelines require power supplies with an output power of 500W or higher to maintain an efficiency of at least 60% under extremely light loads—that is, power supplies with an output power of 500W or higher at 2% load, or power supplies with an output power of less than 500W at 12W load. Future requirements may even extend to power supplies with an output power of 500W or higher at 2% load, or power supplies with an output power of less than 500W at 10W load. Because of these efficiency requirements under extremely light loads, the power management mechanisms of power supplies under these conditions become crucial.

[0004] However, the current drawback of existing power supplies is that their power consumption under extremely light load is not low enough, and they still consume a lot of energy under extremely light load mode; therefore, it is very important to research and develop power supplies with low power consumption under extremely light load. Summary of the Invention

[0005] One object of the present invention is to provide a power supply and a method for saving power consumption thereon, so as to reduce the overall power consumption of the power supply when it is under very light load.

[0006] At least one embodiment of the present invention provides a method for saving power consumption, wherein the method can be used in a power supply. The method may include: generating a monitoring signal based on the operating load of the power supply using a monitoring circuit within the power supply; and generating a control signal based on the monitoring signal using a control signal generation circuit within the power supply to drive at least two switching transistors in a circuit of the power supply, wherein the switching transistors are connected in parallel.

[0007] At least one embodiment of the present invention provides a power supply, wherein the power supply may include a circuit, a monitoring circuit, and a control signal generating circuit coupled between the circuit and the monitoring circuit. Specifically, the circuit can be used to perform a portion of the operation of the power supply, wherein the circuit includes at least two switching transistors connected in parallel. Furthermore, the monitoring circuit can be used to generate a monitoring signal based on the operating load of the power supply, and the control signal generating circuit can generate a control signal based on the monitoring signal to drive the switching transistors.

[0008] The power supply and power-saving method provided in this embodiment of the invention effectively reduce the power consumption of the entire system under extremely light loads by reducing the voltage level used to drive the switching transistors or controlling the number of enabled transistors. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of an electronic device according to one embodiment of the present invention.

[0010] Figure 2 for Figure 1 A schematic diagram of one of the monitoring circuits.

[0011] Figure 3 This describes the workflow of a power saving method according to one embodiment of the present invention.

[0012] [Symbol Explanation]

[0013] 10: Electronic devices

[0014] 50: Central Processing Unit

[0015] 100: Power Supply

[0016] 121: Power Factor Correction Circuit

[0017] 122: Pulse Width Modulation Circuit

[0018] 123: Synchronous rectifier circuit

[0019] 130: Monitoring circuit

[0020] 140: Control signal generation circuit

[0021] RT90: Thermistor

[0022] R9G, R9P, R9K, R9M: Resistors

[0023] C9Z, C9P, C9G: Capacitors

[0024] Q91, Q90: Transistors

[0025] M91: Voltage Regulator

[0026] D95: Diode

[0027] B,AA,5VS: Supply voltage

[0028] CON2: Output port

[0029] 210, 220: Steps Detailed Implementation

[0030] Embodiments of the invention will now be described with reference to the accompanying drawings, in which similar element reference numerals denote similar elements.

[0031] Figure 1 This is a schematic diagram of an electronic device 10 according to an embodiment of the present invention. The electronic device 10 may include a power supply 100 and a central processing unit (CPU) 50. The power supply 100 is used to provide power to the CPU 50 so that the CPU 50 can perform calculations. In this embodiment, the power supply 100 includes a circuit (such as an internal circuit of the power supply) for performing a part of the operation of the power supply. The circuit includes at least one switching element, and the switching element is composed of at least two switching transistors (e.g., two or more switching transistors) connected in parallel. The circuit may be a power factor correction (PFC) circuit 121, a pulse-width modulation (PWM) circuit 122, and / or a synchronous rectification (SR) circuit 123. However, the present invention is not limited to these. Any internal circuit in the power supply 100 that uses at least two switching transistors to implement the switching function can be considered as an example of such a circuit. Additionally, the power supply 100 further includes a monitoring circuit 130 and a control signal generation circuit 140, wherein the control signal generation circuit 140 is coupled between the monitoring circuit 130 and the monitoring circuit 130 (e.g., at least one of the power factor correction circuit 121, the pulse width modulation circuit 122, and the synchronous rectification circuit 123). In this embodiment, the power factor correction circuit 121, the pulse width modulation circuit 122, and the synchronous rectification circuit 123 are all coupled to the control signal generation circuit 140; however, this is for illustrative purposes only and is not intended to limit the scope of the invention.

[0032] In this embodiment, the monitoring circuit 130 can generate a monitoring signal based on the operating load of the power supply 100. The monitoring circuit 130 can be a temperature control circuit, for example... Figure 2As shown, the temperature control circuit includes at least one thermistor, wherein the resistance value of the thermistor changes with the operating temperature of the power supply 100, so that the temperature control circuit generates the monitoring signal based on the operating temperature, thereby using the monitoring signal to indicate the operating temperature of the power supply 100. Figure 2 As shown, the temperature control circuit may include a thermistor RT90, and may also include resistors R9G, R9P, R9K and R9M, capacitors C9Z, C9P and C9G, transistors (such as bipolar junction transistors or metal-oxide-semiconductor field-effect transistors) Q91 and Q90, a voltage regulator M91, and a diode D95. The temperature control circuit can operate on voltages B, AA, and 5VS, and outputs the monitoring signal at output port CON2. However, the temperature control circuit is not limited to using... Figure 2 The monitoring circuit 130 is implemented using the architecture shown, and it is not limited to using the thermistor to generate the monitoring signal. Any device that can detect the operating temperature of the power supply 100 and make the monitoring signal have different voltage levels at different temperatures can be used as an implementation of the monitoring circuit 130. In addition, the control signal generation circuit 140 can generate a control signal based on the monitoring signal to drive the switching transistors. In particular, it can control the voltage level of the control signal based on the monitoring signal, or control the number of switching transistors that are turned on based on the monitoring signal.

[0033] In related technologies, if the highest and lowest voltage levels received by an internal circuit in a power supply are VDD and GND, respectively, the module circuit typically uses a signal with voltage level VDD to turn on the switching element within the module circuit. An embodiment of the present invention provides a novel operating mechanism, allowing the power supply 100 to drive the gate terminals of the switching transistor within the switching element with voltage level VDD under heavy load conditions (e.g., when the central processing unit 50 is operating), thus turning on the switching element; while under very light load conditions (e.g., when the central processing unit 50 is operating at low speed), the control signal generation circuit 140 within the power supply 100 can turn on the switching element by applying a lower voltage level VDD to the gate terminals of these switching transistors, thereby reducing power consumption caused by switching and improving power output efficiency.

[0034] In detail, the total loss P of a switching transistor includes at least the switching loss P0. ds (Switching-Loss) and conduction loss P on (Conducting Loss). Wherein, the switching loss P... ds The effect is more significant under extremely light loads, while the conduction loss P onThe impact is more significant under medium to heavy loads. In practice, using switching transistors made of special materials, with fast switching speeds and small sizes, such as gallium nitride (GaN) devices, can effectively improve the efficiency of power supplies under medium to heavy loads. However, these switching transistors are not only expensive, but also cause significant switching transistor losses under extremely light loads. Generally speaking, the switching loss P... ds and conduction loss P on The following formula can be used to calculate:

[0035]

[0036]

[0037] Taking the TOSHIBA TK20A60W as an example, reducing the voltage level VDD from 18V to 12V can reduce switching power consumption by approximately 56%. Taking the TOSHIBA TK10A60W as another example, reducing the voltage level VDD from 18V to 10V can reduce switching power consumption by approximately 69%.

[0038] Furthermore, since a switching element can be implemented using multiple parallel switching transistors, and in related technologies, the gate terminals of these switching transistors are controlled by the same signal, these switching transistors may simultaneously conduct or simultaneously de-conduct. Embodiments of the present invention provide a novel operating mechanism where the gate terminals of these switching transistors are controlled by their respective corresponding signals. If the power supply 100 operates under heavy load, when the switching element needs to be turned on, all the switching transistors will be turned on simultaneously; while if the power supply 100 operates under very light load, when the switching element needs to be turned on, only a portion (e.g., only one) of these switching transistors will be turned on, thereby reducing the power consumption of the switching element and further improving the output efficiency of the power supply.

[0039] In other words, when the power supply 100 is operating normally, its operating temperature is relatively high. When the control signal generation circuit 140 detects that the monitoring signal indicates that the operating temperature is higher than a predetermined threshold, the control signal generation circuit 140 makes the control signal have a relatively high voltage level to drive the switching transistors in the circuit (e.g., at least one of the power factor correction circuit 121, pulse width modulation circuit 122, and synchronous rectification circuit 123). When it is necessary to turn on the switching element, all of the switching transistors will be turned on to output sufficient power.

[0040] When the power supply 100 is under very light load, its operating temperature is relatively low. When the control signal generation circuit 140 detects that the monitoring signal indicates that the operating temperature is below a predetermined threshold, the control signal generation circuit 140 sets the control signal to a relatively low voltage level to drive the switching transistors in the circuit (e.g., at least one of the power factor correction circuit 121, pulse width modulation circuit 122, and synchronous rectification circuit 123). Specifically, the control signal generation circuit 140 can reduce the voltage level of the control signal used to turn on the switching transistors (e.g., from 18 volts to 12 volts or 10 volts) to reduce the switching loss P of the switching element. ds Alternatively, the control signal may include multiple control bits to drive the switching transistors respectively, and the control signal generating circuit 140 may use the setting of the multiple control bits to turn on only a portion of the switching transistors (e.g., only one of the three switching transistors) when the switching element needs to be turned on, so that not all of the transistors are turned on, thereby avoiding power loss of multiple switching elements.

[0041] Figure 3 The following is a workflow of a power-saving method according to one embodiment of the present invention, wherein the method can be applied to Figure 1 The power supply shown. It should be noted that... Figure 3 The workflow shown is for illustrative purposes only and is not intended to limit the invention. One or more steps may be added, deleted, or modified in this workflow. Furthermore, these steps do not necessarily need to be strictly followed if the same result can be obtained. Figure 3 Execute in the order shown.

[0042] In step 210, the power supply 100 may use its internal monitoring circuit 130 to generate a monitoring signal based on the operating load of the power supply 100.

[0043] In step 220, the power supply may use its internal control signal generation circuit 140 to generate a control signal based on the monitoring signal to drive at least two switching transistors in one of the circuits in the power supply 100 (e.g., at least one of the power factor correction circuit 121, pulse width modulation circuit 122, and synchronous rectification circuit 123), wherein the switching transistors are connected in parallel.

[0044] In summary, embodiments of the present invention reduce power consumption caused by switching by lowering the on-state voltage level of the switching transistors or reducing the number of switching transistors when the power supply 100 is under extremely light load, thereby improving the efficiency of the electronic device 10 (especially the power supply 100).

[0045] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made in accordance with the claims of the present invention shall be covered by the present invention.

Claims

1. A method for saving power consumption for a power supply, comprising the steps of: The power supply includes: a monitoring circuit within the power supply for generating a monitoring signal in response to an operating load of the power supply, the monitoring circuit being a temperature control circuit, the monitoring signal being indicative of an operating temperature of the power supply; and a control signal generating circuit within the power supply for generating a control signal in response to the monitoring signal to drive at least two switching transistors within a circuit of the power supply, wherein the switching transistors are in parallel, the control signal including a plurality of control bits to individually drive the switching transistors; wherein, when the monitoring signal indicates that the operating temperature is below a predetermined threshold, the control signal generating circuit either reduces a voltage level of the control signal for turning on the switching transistors or uses the plurality of control bits to turn on only one of the switching transistors.

2. The method for saving power consumption according to claim 1, wherein, The circuit is a power factor correction circuit, a pulse width modulation circuit or a synchronous rectification circuit.

3. A power supply, characterized by, The power supply includes: a circuit for performing a portion of operation of the power supply, wherein the circuit includes at least two switching transistors, and the switching transistors are in parallel; a monitoring circuit for generating a monitoring signal in response to an operating load of the power supply, the monitoring circuit being a temperature control circuit, the monitoring signal being indicative of an operating temperature of the power supply; and a control signal generating circuit coupled between the circuit and the monitoring circuit for generating a control signal in response to the monitoring signal to drive the switching transistors, the control signal including a plurality of control bits to individually drive the switching transistors; wherein, when the monitoring signal indicates that the power supply enters a very light load state, the control signal generating circuit either reduces a voltage level of the control signal for turning on the switching transistors or uses the plurality of control bits to turn on only one of the switching transistors. The circuit is a power factor correction circuit, a pulse width modulation circuit or a synchronous rectification circuit.

4. The power supply of claim 3, wherein ​

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