Linear voltage regulator and voltage regulation method

Abstract

This disclosure relates to linear voltage regulators and voltage regulation methods. A linear voltage regulator includes a switching element, an error amplifier circuit, a feedback circuit, and a trigger element. A first terminal of the switching element receives an input voltage, and a second terminal outputs an output voltage to a load. A first input terminal of the error amplifier circuit receives a reference voltage, and the output terminal of the error amplifier circuit is electrically connected to the control terminal of the switching element. The feedback circuit is electrically connected between the second terminal and the second input terminal of the error amplifier circuit. The trigger element is electrically connected to the control terminal and the load, and receives a trigger signal from the load. The trigger element outputs a trigger voltage to the control terminal according to the trigger signal, and the switching element changes the output voltage according to the trigger voltage.

Description

Technical Field

[0001] This disclosure relates to a technique for outputting a corresponding voltage to a load on demand, and in particular to a linear regulator and a linear regulation method. Background Technology

[0002] A linear regulator (LDO) is a device used to maintain voltage stability. Linear regulators are used in power supplies to provide output voltage to the load. However, if the load's power demand suddenly increases, the linear regulator will not be able to respond quickly enough, causing a sharp drop in the output voltage and affecting voltage stability. Therefore, there is a need for a linear regulator that can adjust in real time according to load demand. Summary of the Invention

[0003] One aspect of this disclosure is a linear voltage regulator, comprising a switching element, an error amplifier circuit, a feedback circuit, and a trigger element. The switching element includes a first terminal, a second terminal, and a control terminal. The switching element receives an input voltage through the first terminal and outputs an output voltage to a load through the second terminal. The error amplifier circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal receives a reference voltage, and the output terminal is electrically connected to the control terminal. The feedback circuit is electrically connected between the second terminal of the switching element and the second input terminal of the error amplifier circuit. The trigger element is electrically connected between the control terminal and the load to receive a trigger signal from the load. The trigger element outputs a trigger voltage to the control terminal according to the trigger signal, and the switching element changes the output voltage according to the trigger voltage.

[0004] Another aspect of this disclosure is a linear voltage regulation method, comprising the following steps: receiving an input voltage through a first terminal of a switching element and outputting an output voltage to a load through a second terminal of the switching element; transmitting a feedback voltage to an error amplifier circuit based on the output voltage through a feedback circuit; comparing a reference voltage with the feedback voltage through the error amplifier circuit to control the voltage value at the control terminal of the switching element; receiving a trigger signal and generating a trigger voltage at the control terminal through a trigger element, wherein the trigger signal is used to control the load to drive the circuit within the load; and changing the output voltage based on the trigger voltage.

[0005] Another aspect of this disclosure is a linear regulator, comprising a control circuit, a switching element, an error amplifier circuit, a feedback circuit, and a trigger element. The control circuit provides a trigger signal to the load to drive circuitry within the load. The switching element includes a first terminal, a second terminal, and a control terminal. The switching element receives an input voltage through the first terminal and outputs an output voltage to the load through the second terminal. The error amplifier circuit includes a first input terminal, a second input terminal, and an output terminal. The first input terminal receives a reference voltage, and the output terminal is electrically connected to the control terminal of the switching element. The feedback circuit is electrically connected between the second terminal of the switching element and the second input terminal of the error amplifier circuit. The trigger element is electrically connected between the control terminal and the control circuit to receive a trigger signal from the control circuit. The trigger element outputs a trigger voltage to the control terminal according to the trigger signal, and the switching element changes the output voltage according to the trigger voltage.

[0006] This disclosure describes a trigger element that receives a trigger signal in real time when the load's power demand is about to change, and generates a trigger voltage at the control terminal so that the output voltage of the switching element can change accordingly, thereby ensuring power supply stability. Attached Figure Description

[0007] Figure 1 The diagram shown is a schematic of a linear regulator according to some embodiments of the present disclosure.

[0008] Figure 2 The diagram shown is a schematic flowchart of a linear voltage regulation method according to some embodiments of the present disclosure. Detailed Implementation

[0009] The following drawings disclose several embodiments of the present invention. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. Furthermore, for the sake of simplicity, some conventional structures and elements will be shown in the drawings in a simple schematic manner.

[0010] In this document, when an element is referred to as a “connection” or “coupled,” it may mean an “electrical connection” or “electrical coupling.” “Connection” or “coupled” can also be used to indicate the operation or interaction between two or more elements. Furthermore, although terms such as “first,” “second,” etc., are used herein to describe different elements, these terms are merely used to distinguish elements or operations described using the same technical terminology. Unless the context clearly indicates otherwise, these terms do not specifically refer to or imply any order or sequence, nor are they intended to limit the invention.

[0011] Figure 1The diagram shows a linear regulator 100 according to a partial embodiment of the present disclosure. The linear regulator 100 includes a switching element T1, an error amplifier circuit 110, a feedback circuit 120, and a trigger element C1. The switching element T1 includes a first terminal Na, a second terminal Nb, and a control terminal Nc. The first terminal Na is electrically connected to the input voltage Vin, allowing the switching element T1 to receive the input voltage Vin through the first terminal Na. The switching element T1 generates an output voltage Vout based on the input voltage Vin and the voltage value of the control terminal Nc, and provides the output voltage to the load 200 through the second terminal Nb.

[0012] In some embodiments, the switching element T1 is implemented using an N-type metal-oxide-semiconductor field-effect transistor (NMOS), but this is not a limitation. The switching element T1 can also be implemented using multiple interconnected NMOS transistors. Furthermore, in other embodiments, the switching element T1 can be implemented using a P-type metal-oxide-semiconductor field-effect transistor (PMOS), a bipolar junction transistor (BJT), a thin-film transistor (TFT), or other different types of switching elements. Since those skilled in the art will understand how the switching element T1 generates the output voltage Vout based on the input voltage Vin, further details are omitted here.

[0013] The error amplifier circuit 110 includes a first input terminal N1, a second input terminal N2, and an output terminal N3. In some embodiments, the error amplifier circuit 110 may be implemented by an operational amplifier. The first input terminal N1 is electrically connected to a reference voltage Vref. The second input terminal N2 is electrically connected to the second terminal Nb of the switching element T1. The output terminal N3 is electrically connected to the control terminal Nc of the switching element T1.

[0014] Feedback circuit 120 is electrically connected between the second terminal Nb of switching element T1 and the second input terminal N2 of error amplifier circuit 110. Feedback circuit 120 is used to transmit feedback voltage Vfb to error amplifier circuit 110 according to output voltage Vout. In some embodiments, error amplifier circuit 110 is used to compare reference voltage Vref and feedback voltage Vfb, and amplify the difference between reference voltage Vref and feedback voltage Vfb to output the corresponding voltage value to control terminal Nc, for example, providing the amplified difference to control terminal Nc.

[0015] Specifically, in one embodiment, the feedback circuit 120 includes a first resistor R1 and a second resistor R2. The first resistor R1 is electrically connected to the second terminal Nb of the switching element T1, and the second resistor R2 is connected to the first resistor R1, the second input terminal N2, and another reference voltage (such as ground as shown in the figure). In other words, the second input terminal N2 of the error amplifier circuit 110 is electrically connected between the first resistor R1 and the second resistor R2. Therefore, the feedback circuit 120 divides the output voltage Vout according to the impedance values ​​of the first resistor R1 and the second resistor R2 to generate the feedback voltage Vfb.

[0016] In some embodiments, the impedance of the feedback circuit is between 1,000 and 3,000 ohms. That is, the sum of the impedances of the first resistor R1 and the second resistor R2 is 1,000 to 3,000 ohms (e.g., 2.2,000 ohms). The impedance ratio of the first resistor R1 and the second resistor R2 can be adjusted according to requirements, which will not be elaborated here.

[0017] Under normal circumstances, if the voltage or current required by the load 200 does not change, the feedback voltage Vfb provided by the feedback circuit 120 to the error amplifier circuit 110 will be approximately the same as the reference voltage Vref. Therefore, the voltage value output by the error amplifier circuit 110 to the control terminal Nc will be approximately the same, and the output voltage Vout output by the switching element T1 will also remain stable.

[0018] Conversely, if the voltage or current required by the load 200 changes suddenly in a short period of time (e.g., the current demand increases instantaneously), the voltage value output from the error amplifier circuit 110 to the control terminal Nc will increase accordingly. The output voltage Vout of the switching element T1 will also increase accordingly due to the increase in the voltage value at the control terminal, ensuring that the voltage at the second terminal Nb of the switching element T1 does not drop drastically when a large current is supplied to the load 200.

[0019] The trigger element C1 is electrically connected between the control terminal Nc of the switching element T1 and the load 200. In this embodiment, the trigger element C1 is a capacitor and can receive a trigger signal St from the load 200. The trigger signal St is a signal used to control the load 200 to drive a specific circuit (or module) within the load 200, or a signal generated when the specific circuit (or module) within the load 200 is driven. When the specific circuit is driven, the power demand of the load 200 itself will change, and the load 200 will obtain a corresponding change in electrical energy (e.g., a higher current demand) from the linear regulator 100.

[0020] In another embodiment, the trigger signal St may be generated by the linear regulator 100. For example... Figure 1As shown, the linear regulator 100 may include control circuitry 130 for providing a trigger signal St to the load 200. Control circuitry 130 may be a central processing unit (CPU), a system-on-chip (SoC), an application processor, an audio processor, a digital signal processor, or a function-specific processing chip or controller.

[0021] The trigger element C1 is electrically connected between the control terminal Nc and the trigger terminal Nt. In some embodiments, the trigger terminal Nt is electrically connected only to the load 200. In other embodiments, the trigger terminal Nt is electrically connected to both the load 200 and the control circuit 130, so that it can receive a trigger signal St from either the load 200 or the control circuit 130, depending on the circumstances.

[0022] Upon receiving the trigger signal St, trigger element C1 outputs a trigger voltage Vg to the control terminal Nc based on the trigger signal St. At this time, switching element T1 changes the output voltage Vout supplied to the load 200 according to the voltage value at the control terminal Nc (i.e., the trigger voltage Vg). In one embodiment, trigger element C1 is a capacitor, and the trigger signal St is a pulse control signal. Since a capacitor tends to maintain a voltage difference across its terminals (i.e., capacitive coupling), when the voltage at one end of trigger element C1 changes due to the pulse signal of trigger signal St, the voltage at the other end will change accordingly, thereby generating a trigger voltage Vg at the control terminal Nc.

[0023] In some embodiments, the trigger voltage Vg is used to increase the voltage value of the control terminal Nc, and the switching element T1 is used to increase the output voltage Vout according to the trigger voltage Vg. Specifically, when the power demand of the load 200 suddenly increases (e.g., from a light load to a heavy load), the load 200 will draw a large current from the second terminal Nb. At this time, the feedback circuit 120 alone may not be able to quickly transmit the voltage change (output voltage Vout) of the second terminal Nb to the error amplifier circuit 110, that is, the error amplifier circuit 110 may not be able to adjust the voltage of the second terminal Nb in real time. Therefore, by detecting the trigger signal St by the trigger element C1, the voltage change can be quickly reflected to the second terminal Nb, so that the switching element T1 can change the output voltage Vout in real time.

[0024] Figure 2 The flowchart shown is a linear voltage regulation method according to the present disclosure. In step S201, the switching element T1 receives the input voltage Vin through the first terminal Na, and outputs the output voltage Vout according to the input voltage Vin at the second terminal Nb.

[0025] In step S202, the feedback circuit 120 transmits the feedback voltage Vfb to the error amplifier circuit 110 based on the output voltage Vout. In step S203, the error amplifier circuit 110 compares the reference voltage Vref with the feedback voltage Vfb and controls the voltage value of the control terminal Nc of the switching element T1 accordingly.

[0026] In step S204, when the load 200 is about to be started, or when it needs to drive a specific internal circuit or module, the load 200 will perform this action according to the trigger signal St, or generate the trigger signal St before performing the action. At this time, the trigger element C1 will receive the trigger signal St (e.g., a pulse signal) from the load 200 or the control circuit 130 through the trigger terminal Nt.

[0027] In step S205, the trigger element C1 generates a trigger voltage Vg on the control terminal Nc according to the trigger signal St, so that the switching element T1 can change the output voltage Vout according to the input voltage Vin and the trigger voltage Vg (that is, the voltage value of the control terminal Nc at this time).

[0028] The components, method steps, or technical features in the foregoing embodiments can be combined with each other, and are not limited to the order of textual description or graphical presentation in this disclosure.

[0029] Although the present disclosure has been described above with reference to embodiments, it is not intended to limit the present disclosure. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the appended claims.

[0030] [Symbol Explanation]

[0031] 100: Linear regulator

[0032] 110: Error Amplifier Circuit

[0033] 120: Feedback circuit

[0034] 130: Control Circuit

[0035] 200: Load

[0036] T1: Switching element

[0037] C1: Trigger element

[0038] R1: First resistor

[0039] R2: Second resistor

[0040] N1: First input terminal

[0041] N2: Second input terminal

[0042] N3: Output terminal

[0043] Na: First end

[0044] Nb: Second end

[0045] Nc: Control terminal

[0046] Nt: Trigger end

[0047] St: Trigger signal

[0048] Vin: Input voltage

[0049] Vout: First end

[0050] Vref: Reference voltage

[0051] Vfb: Feedback voltage

[0052] Vg: Trigger voltage

[0053] S201-S205: Steps

Claims

1. A linear regulator, comprising: A switching element includes a first terminal, a second terminal and a control terminal, wherein the switching element is used to receive an input voltage through the first terminal and to output an output voltage to a load through the second terminal; An error amplifier circuit includes a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is used to receive a reference voltage, and the output terminal is electrically connected to the control terminal. A feedback circuit is electrically connected between the second terminal of the switching element and the second input terminal of the error amplifier circuit; and A trigger element is electrically connected between the control terminal and the load to receive a trigger signal from the load, wherein the trigger element is used to output a trigger voltage to the control terminal according to the trigger signal, and the switching element is used to change the output voltage according to the trigger voltage. The first end of the trigger element is directly connected to the load to receive a trigger signal, and the second end of the trigger element is directly connected to the control terminal.

2. The linear regulator according to claim 1, wherein the trigger element is a capacitor.

3. The linear regulator according to claim 1, wherein the trigger voltage is used to increase the voltage value of the control terminal, and the switching element is used to increase the output voltage according to the trigger voltage.

4. The linear regulator according to claim 1, wherein the feedback circuit includes a first resistor and a second resistor, the second input terminal of the error amplifier circuit is electrically connected between the first resistor and the second resistor, and the impedance value of the feedback circuit is between 1 kΩ and 3 kΩ.

5. A linear voltage regulation method, comprising: An input voltage is received through a first terminal of a switching element, and an output voltage is output to a load through a second terminal of the same switching element. A feedback circuit transmits a feedback voltage to an error amplifier circuit based on the output voltage. The error amplifier circuit compares a reference voltage with the feedback voltage to control the voltage value at the control terminal of one of the switching elements. A trigger element receives a trigger signal and generates a trigger voltage at the control terminal, wherein the trigger signal is used to control the load to drive a circuit within the load; and The output voltage is changed according to the trigger voltage; The first end of the trigger element is directly connected to the load to receive a trigger signal, and the second end of the trigger element is directly connected to the control terminal.

6. The linear voltage regulation method according to claim 5, wherein the triggering element is a capacitor, and the capacitor receives the trigger signal through the load or a control circuit.

7. The linear voltage regulation method according to claim 5, wherein the trigger voltage is used to increase the voltage value of the control terminal, and the linear voltage regulation method further comprises: The output voltage is increased by the switching element according to the trigger voltage.

8. A linear regulator, comprising: A control circuit for providing a trigger signal to a load to drive a circuit within the load; A switching element includes a first terminal, a second terminal, and a control terminal, wherein the switching element is used to receive an input voltage through the first terminal and output an output voltage to the load through the second terminal; An error amplifier circuit includes a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is used to receive a reference voltage, and the output terminal is electrically connected to a control terminal of the switching element. A feedback circuit is electrically connected between the second terminal of the switching element and the second input terminal of the error amplifier circuit; and A trigger element is electrically connected between the control terminal and the control circuit to receive a trigger signal from the control circuit. The trigger element is used to output a trigger voltage to the control terminal according to the trigger signal, and the switching element is used to change the output voltage according to the trigger voltage.

9. The linear regulator of claim 8, wherein the trigger element is a capacitor, the trigger voltage is used to increase the voltage value of the control terminal, and the switching element is used to increase the output voltage according to the trigger voltage.

10. The linear regulator according to claim 8, wherein the feedback circuit includes a first resistor and a second resistor, the second input terminal of the error amplifier circuit is electrically connected between the first resistor and the second resistor, and the impedance value of the feedback circuit is between 1 kΩ and 3 kΩ.

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