Voltage control circuit

Abstract

The utility model provides a voltage control circuit which is coupled between an input voltage end and an amplifying circuit. The voltage control circuit comprises a comparator, a first transistor, an inductor and a first capacitor. The output end of the comparator is used for outputting control voltage. The first transistor is used for outputting a regulation voltage according to a control voltage. The first end of the first transistor is coupled with an input voltage end and is used for receiving an input voltage. The control end of the first transistor is coupled with the output end of the comparator and is used for receiving the control voltage. The second end of the first transistor is coupled to the amplifying circuit and is used for outputting a regulated voltage. The inductor is coupled between the second end of the first transistor and the amplifying circuit. The first capacitor is coupled to the second end of the first transistor. The voltage control circuit provided by the utility model can effectively reduce the misjudgment of the comparator in the voltage control circuit.

Description

Technical Field

[0001] This utility model relates to a control circuit, and more particularly to a voltage control circuit. Background Technology

[0002] To address the issue of excessively high power supply voltage in power amplifiers (PAs), a low-dropout regulator (LDO) can be used to regulate the voltage between the power amplifier and the power supply. However, when the power amplifier outputs a large voltage swing, the comparator within the LDO may misjudge the voltage as too high at the wrong time and perform regulation, thus reducing the performance of the power amplifier. Utility Model Content

[0003] This invention provides a voltage control circuit that can effectively reduce comparator misjudgments in voltage control circuits.

[0004] The voltage control circuit of this invention is coupled between the input voltage terminal and the amplifier circuit. The voltage control circuit includes a comparator, a first transistor, an inductor, and a first capacitor. The comparator outputs a control voltage based on a reference voltage and a feedback voltage. The comparator includes a first input terminal, a second input terminal, and an output terminal. The first input terminal receives the reference voltage, the second input terminal receives the feedback voltage, and the output terminal outputs the control voltage. The first transistor outputs an regulated voltage based on the control voltage. The first transistor includes a first terminal, a second terminal, and a control terminal. The first terminal is coupled to the input voltage terminal and receives the input voltage. The control terminal is coupled to the output terminal of the comparator and receives the control voltage. The second terminal is coupled to the amplifier circuit and outputs the regulated voltage. The inductor is coupled between the second terminal of the first transistor and the amplifier circuit. The first capacitor is coupled to the second terminal of the first transistor.

[0005] In an embodiment of this utility model, the voltage control circuit further includes a second capacitor coupled between the second input terminal of the comparator and the reference voltage terminal.

[0006] In an embodiment of this utility model, the voltage control circuit further includes a third capacitor coupled between the output terminal and the reference voltage terminal of the comparator.

[0007] In an embodiment of this utility model, the voltage control circuit further includes a fourth capacitor and a fifth capacitor. The fourth capacitor is coupled between the first terminal of the first transistor and the control terminal, and the fifth capacitor is coupled between the control terminal and the second terminal of the first transistor.

[0008] In an embodiment of this invention, the capacitance value of the fourth capacitor is equal to the capacitance value of the fifth capacitor.

[0009] In an embodiment of this utility model, the first capacitor is coupled between the second terminal and the first terminal of the first transistor.

[0010] In an embodiment of this utility model, the capacitance value of the first capacitor is greater than or equal to 10pF and less than or equal to 1000pF.

[0011] In an embodiment of this utility model, the voltage control circuit further includes a voltage divider circuit coupled to the second terminal of the first transistor, the second input terminal of the comparator, and the reference voltage terminal.

[0012] In an embodiment of this utility model, the amplification circuit includes a power amplifier, which includes a plurality of stacked second transistors.

[0013] This invention also provides a voltage control circuit coupled between an input voltage terminal and an amplifier circuit. The voltage control circuit includes a comparator, a first transistor, a first capacitor, and a second capacitor. The comparator outputs a control voltage based on a reference voltage and a feedback voltage. The comparator includes a first input terminal, a second input terminal, and an output terminal. The first input terminal receives the reference voltage, the second input terminal receives the feedback voltage, and the output terminal outputs the control voltage. The first transistor outputs an regulated voltage based on the control voltage. The first transistor includes a first terminal, a second terminal, and a control terminal. The first terminal is coupled to the input voltage terminal and receives the input voltage. The control terminal is coupled to the output terminal of the comparator and receives the control voltage. The second terminal is coupled to the amplifier circuit and outputs the regulated voltage. The first capacitor is coupled between the first terminal of the first transistor and the control terminal. The second capacitor is coupled between the second terminal of the first transistor and the control terminal.

[0014] In an embodiment of this utility model, the voltage control circuit further includes a third capacitor coupled between the second terminal and the first terminal of the first transistor.

[0015] In an embodiment of this utility model, the voltage control circuit further includes a fourth capacitor coupled between the second input terminal and the reference voltage terminal of the comparator.

[0016] In an embodiment of this utility model, the voltage control circuit further includes a fifth capacitor coupled between the output terminal and the reference voltage terminal of the comparator.

[0017] In an embodiment of this utility model, the voltage control circuit further includes an inductor coupled between the input voltage terminal and the first terminal of the first transistor.

[0018] In an embodiment of this utility model, the voltage control circuit further includes an inductor coupled between the second terminal of the first transistor and the amplifier circuit.

[0019] In an embodiment of this utility model, the capacitance value of the first capacitor is greater than or equal to 10pF and less than or equal to 1000pF, and the capacitance value of the second capacitor is greater than or equal to 10pF and less than or equal to 1000pF.

[0020] In embodiments of this invention, a voltage divider circuit is further included, coupled to the second terminal of the first transistor, the second input terminal of the comparator, and the reference voltage terminal.

[0021] In an embodiment of this utility model, the amplification circuit includes a power amplifier, which includes a plurality of stacked second transistors.

[0022] Based on the above, a voltage control circuit in one embodiment of the present invention can reduce the voltage swing of the amplified radio frequency signal from the amplifier circuit by using an inductor coupled between the second terminal of the first transistor and the amplifier circuit, and a capacitor coupled between the second terminal of the first transistor. Alternatively, another voltage control circuit in one embodiment of the present invention can use a capacitor coupled between the first terminal of the first transistor and the control terminal, and a capacitor coupled between the second terminal of the first transistor and the control terminal, to make the voltage swing generated by the amplified radio frequency signal from the amplifier circuit at the first terminal, the second terminal, and the control terminal of the first transistor approximately uniform. In this way, the comparator misjudgment in the voltage control circuit can be effectively reduced.

[0023] To make the above-mentioned features and advantages of this utility model more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description

[0024] Figure 1 and Figure 2 This is a schematic diagram of the voltage control circuit according to the present invention. Detailed Implementation

[0025] Figure 1This is a circuit block diagram of a voltage control circuit according to an embodiment of the present invention. The voltage control circuit 100 is coupled between the input voltage terminal VCC2 and the amplifier circuit PA1, wherein the input voltage terminal VCC2 is used to receive the input voltage. The voltage control circuit 100 includes a comparator A1, a first transistor M1, an inductor L1, and capacitors C1-C5. The first transistor M1 is used to output an adjustable voltage VCC according to the control voltage. The first transistor M1 can be, for example, a P-type field-effect transistor (FET). The first transistor M1 includes a first terminal, a second terminal, and a control terminal. The first terminal (e.g., the source terminal) is coupled to the input voltage terminal VCC2 and is used to receive the input voltage from the input voltage terminal VCC2. The second terminal (e.g., the drain terminal) is coupled to the amplifier circuit PA1 and is used to output the adjustable voltage VCC. The control terminal (e.g., the gate terminal) is coupled to the output terminal of the comparator A1 and is used to receive the control voltage. The inductor L1 is coupled between the second terminal of the first transistor M1 and the amplifier circuit PA1. The first input terminal of comparator A1 (e.g., the positive input terminal) is used to receive a reference voltage VA. The second input terminal of comparator A1 (e.g., the negative input terminal) is coupled to a reference voltage terminal and used to receive a feedback voltage. The reference voltage terminal may be, for example, ground, but is not limited thereto. Capacitor C4 is coupled between the second input terminal of comparator A1 and the reference voltage terminal. The output terminal of comparator A1 is coupled to the control terminal of the first transistor M1, for example, through a resistor R3, where the resistor R3 serves to block radio frequency current. Capacitor C5 is coupled between the output terminal of comparator A1 and the reference voltage terminal. Capacitor C1 is coupled between the control terminal and the first terminal of the first transistor M1, capacitor C2 is coupled between the control terminal and the second terminal of the first transistor M1, and capacitor C3 is coupled between the first terminal and the second terminal of the first transistor M1.

[0026] The voltage control circuit 100 may further include a voltage divider circuit 102 coupled to the second input terminal of comparator A1, the second terminal of the first transistor M1, and the reference voltage terminal, and the voltage divider circuit 102 is used to provide a feedback voltage. Further, the voltage divider circuit 102 is coupled between the second input terminal of comparator A1 and capacitor C4, and the voltage divider circuit 102 may include, for example, resistors R1 and R2, which are connected in series between the second terminal of the first transistor M1 and the reference voltage terminal. The common contact of resistors R1 and R2 is coupled to the second input terminal of comparator A1, and capacitor C4 is coupled between the common contact of resistors R1 and R2 and the reference voltage terminal. In this embodiment, the feedback voltage is formed by dividing the regulated voltage VCC output from the second terminal of the first transistor M1 through the voltage divider circuit 102. When the voltage control circuit 100 is not regulated, the regulated voltage VCC may be equal to the voltage from the input voltage terminal VCC2.

[0027] Comparator A1 outputs the aforementioned control voltage based on the reference voltage VA and the feedback voltage provided by the voltage divider circuit 102 to control the conduction state of the first transistor M1. Further, assuming the reference voltage VA is VA, the resistance of resistor R1 is R1, the resistance of resistor R2 is R2, and the voltage from the input voltage terminal VCC2 is VCC2. When the voltage control circuit 100 starts operating, the second input terminal of comparator A1 receives the feedback voltage formed after voltage division processing by the voltage divider circuit 102 from the input voltage terminal VCC2, and the first input terminal of comparator A1 receives the reference voltage VA. Then, the feedback voltage is compared with the reference voltage VA. Furthermore, the comparator A1's determination of whether the "feedback voltage is greater than the reference voltage VA" can be seen as determining whether "VCC2 is greater than VA(1+(R2 / R1)"). When comparator A1 determines that VCC2 is greater than VA(1+(R2 / R1)), comparator A1 can output a control voltage to the first transistor M1 to change the conduction level of the first transistor M1 (when the voltage value VCC2 is too large, it is usually necessary to control the conduction level of the first transistor M1 to decrease), thereby controlling the voltage value of the regulating voltage VCC output by the first transistor M1 to VA(1+(R2 / R1), so that the voltage control circuit 100 achieves voltage regulation. On the other hand, in voltage When the control circuit 100 is operating continuously, the second input terminal of comparator A1 continuously receives the feedback voltage formed after the regulated voltage VCC is divided by the voltage divider circuit 102, and the first input terminal of comparator A1 continuously receives the reference voltage VA. Comparator A1 continuously compares the feedback voltage with the reference voltage VA. When the feedback voltage is less than or equal to the reference voltage VA, that is, when the regulated voltage VCC output from the second terminal of the first transistor M1 is controlled to be below VA(1+(R2 / R1), it indicates that the voltage control circuit 100 does not need to perform voltage regulation. At this time, comparator A1 can output a control voltage to the first transistor M1 to increase the conduction level of the first transistor M1.

[0028] Amplifier circuit PA1 is coupled between the RF signal input terminal RFIN and the RF signal output terminal RFOUT. Amplifier circuit PA1 may include multiple stacked second transistors M2. For example, in this embodiment, amplifier circuit PA1 includes two stacked N-type field-effect transistors (FETs), but this is not a limitation. Amplifier circuit PA1 amplifies the RF signal from the RF signal input terminal RFIN to generate an amplified RF signal, which is then output through the RF signal output terminal RFOUT.

[0029] In this embodiment, inductor L1 serves to block radio frequency current. Furthermore, inductor L1 reduces the voltage swing generated between amplifier circuit PA1 and voltage control circuit 100 by the amplified radio frequency signal (RF signal) from amplifier circuit PA1. This reduces the possibility of comparator A1 being affected by excessive voltage swing of the amplified radio frequency signal. Capacitors C1 to C3 are used to make the voltage swing generated by the amplified radio frequency signal at the first terminal, second terminal, and control terminal of the first transistor M1 more consistent, thereby reducing the coupling of the amplified radio frequency signal (AC signal) to the control terminal of the first transistor M1, and thus reducing the possibility of comparator A1 misjudging. In addition, capacitor C3 can also be used to guide at least a portion of the amplified radio frequency signal to the reference voltage terminal (for the amplified radio frequency signal, the input voltage terminal VCC2 is the reference voltage terminal), thereby reducing the voltage swing generated by the amplified radio frequency signal. On the other hand, by setting capacitors C1 to C3, the equivalent on-resistance of the first transistor M1 decreases when the voltage control circuit 100 is regulating voltage. This reduces the impact of the load of the first transistor M1 on the amplifier circuit PA1 and increases the gain of the amplifier circuit PA1. Furthermore, if there is still a low-amplified radio frequency signal (AC signal) coupled to the control terminal of the first transistor M1, in addition to using the aforementioned resistor R3 coupled between the control terminal of the first transistor M1 and the output terminal of the comparator A1 to block the radio frequency current, capacitors C4 and C5 can be used as AC coupling elements to guide at least a portion of the amplified radio frequency signal to the reference voltage terminal, thereby reducing the impact of the amplified radio frequency signal on the judgment of the comparator A1.

[0030] It is worth noting that, for example, when the frequency of the amplified radio frequency signal is 2.45 gigahertz (GHz), the capacitance value of the capacitors C1 to C5 can be, for example, 100pF. However, this is not a limitation. The capacitance value of capacitors C1 to C5 can also be set to greater than or equal to 10pF and less than or equal to 1000pF. Furthermore, as the frequency of the amplified radio frequency signal increases, reducing the capacitance value of capacitors C1 to C5 can also achieve the same effect.

[0031] Furthermore, in other embodiments, the inductor L1 is not limited to being disposed between the first transistor M1 and the amplifier circuit PA1, such as... Figure 2 As shown in the embodiments, in Figure 2 In this embodiment, the inductor L1' included in the voltage control circuit 100' is disposed between the input voltage terminal VCC2 and the first terminal of the first transistor M1. Figure 2 In this embodiment, inductor L1' is used for impedance matching; the implementation details of the remaining circuit elements are as follows. Figure 1 The embodiments are similar, and those skilled in the art should be able to infer from the content of the above embodiments. Figure 2The implementation methods of these embodiments are therefore not described in detail here. In other embodiments, Figure 2 The inductance L1' can also be implemented by a wire bond connected to the pad.

[0032] It is worth noting that, with Figure 1 Regarding the voltage control circuit 100 architecture, in other embodiments, the integrated circuit may preferentially include inductor L1 and capacitor C3, while capacitors C4, C5, C1, and C2 may be omitted; furthermore, Figure 1 and Figure 2 Regarding the voltage control circuits 100 and 100' architecture, in other embodiments, capacitors C1 and C2 may be preferentially selected (for example, when the capacitance values ​​of capacitors C1 and C2 are sufficiently large), while capacitors C3, C4, C5 and inductors L1 / L1' may be omitted, without being limited to the above embodiments.

[0033] In summary, one voltage control circuit of this invention can reduce the voltage swing of the amplified radio frequency signal from the amplifier circuit by using an inductor coupled between the second terminal of the first transistor and the amplifier circuit, and a capacitor coupled between the second terminal of the first transistor. Alternatively, another voltage control circuit of this invention can use a capacitor coupled between the first terminal of the first transistor and the control terminal, and a capacitor coupled between the second terminal of the first transistor and the control terminal, to make the voltage swing generated by the amplified radio frequency signal from the amplifier circuit at the first terminal, the second terminal, and the control terminal of the first transistor approximately uniform. This effectively reduces the possibility of comparator misjudgment in the voltage control circuit.

[0034] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A voltage control circuit, characterized in that, Coupled between the input voltage terminal and the amplifier circuit, the voltage control circuit includes: A comparator is used to output a control voltage based on a reference voltage and a feedback voltage. The comparator includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is used to receive the reference voltage, the second input terminal is used to receive the feedback voltage, and the output terminal is used to output the control voltage. A first transistor is used to output an regulated voltage according to the control voltage. The first transistor includes a first terminal, a second terminal, and a control terminal. The first terminal is coupled to the input voltage terminal and is used to receive the input voltage. The control terminal is coupled to the output terminal of the comparator and is used to receive the control voltage. The second terminal is coupled to the amplifier circuit and is used to output the regulated voltage. An inductor, coupled between the second terminal of the first transistor and the amplifier circuit; and The first capacitor is coupled to the second terminal of the first transistor.

2. The voltage control circuit according to claim 1, characterized in that, It also includes a second capacitor coupled between the second input terminal and the reference voltage terminal of the comparator.

3. The voltage control circuit according to claim 1, characterized in that, It also includes a third capacitor, coupled between the output terminal and the reference voltage terminal of the comparator.

4. The voltage control circuit according to claim 1, characterized in that, It also includes a fourth capacitor and a fifth capacitor, wherein the fourth capacitor is coupled between the first terminal of the first transistor and the control terminal, and the fifth capacitor is coupled between the control terminal and the second terminal of the first transistor.

5. The voltage control circuit according to claim 4, characterized in that, The capacitance value of the fourth capacitor is equal to the capacitance value of the fifth capacitor.

6. The voltage control circuit according to claim 4, characterized in that, The first capacitor is coupled between the second terminal and the first terminal of the first transistor.

7. The voltage control circuit according to claim 1, characterized in that, The capacitance value of the first capacitor is greater than or equal to 10pF and less than or equal to 1000pF.

8. The voltage control circuit according to claim 1, characterized in that, It also includes a voltage divider circuit coupled to the second terminal of the first transistor, the second input terminal of the comparator, and the reference voltage terminal.

9. The voltage control circuit according to claim 1, characterized in that, The amplifier circuit includes a power amplifier, which includes a plurality of stacked second transistors.

10. A voltage control circuit, characterized in that, Coupled between the input voltage terminal and the amplifier circuit, the voltage control circuit includes: A comparator is used to output a control voltage based on a reference voltage and a feedback voltage. The comparator includes a first input terminal, a second input terminal, and an output terminal. The first input terminal is used to receive the reference voltage, the second input terminal is used to receive the feedback voltage, and the output terminal is used to output the control voltage. A first transistor is used to output an regulated voltage according to the control voltage. The first transistor includes a first terminal, a second terminal, and a control terminal. The first terminal is coupled to the input voltage terminal and is used to receive the input voltage. The control terminal is coupled to the output terminal of the comparator and is used to receive the control voltage. The second terminal is coupled to the amplifier circuit and is used to output the regulated voltage. A first capacitor is coupled between the first terminal of the first transistor and the control terminal; and The second capacitor is coupled between the second terminal of the first transistor and the control terminal.

11. The voltage control circuit according to claim 10, characterized in that, It also includes a third capacitor coupled between the second terminal and the first terminal of the first transistor.

12. The voltage control circuit according to claim 10, characterized in that, It also includes a fourth capacitor, coupled between the second input terminal and the reference voltage terminal of the comparator.

13. The voltage control circuit according to claim 10, characterized in that, It also includes a fifth capacitor, coupled between the output terminal and the reference voltage terminal of the comparator.

14. The voltage control circuit according to claim 10, characterized in that, It also includes an inductor coupled between the input voltage terminal and the first terminal of the first transistor.

15. The voltage control circuit according to claim 10, characterized in that, It also includes an inductor coupled between the second terminal of the first transistor and the amplifier circuit.

16. The voltage control circuit according to claim 10, characterized in that, The capacitance of the first capacitor is greater than or equal to 10pF and less than or equal to 1000pF, and the capacitance of the second capacitor is greater than or equal to 10pF and less than or equal to 1000pF.

17. The voltage control circuit according to claim 10, characterized in that, It also includes a voltage divider circuit coupled to the second terminal of the first transistor, the second input terminal of the comparator, and the reference voltage terminal.

18. The voltage control circuit according to claim 10, characterized in that, The amplifier circuit includes a power amplifier, which includes a plurality of stacked second transistors.

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