Amplifier circuit, radio frequency chip and electronic equipment

Abstract

The invention provides an amplifier circuit, a radio frequency chip and electronic equipment. The amplifier circuit comprises a multi-stage power amplifier and a protection circuit, wherein the multi-stage power amplifier is configured to receive a radio frequency input signal, perform multi-stage amplification on the radio frequency input signal and then output the radio frequency input signal; and the protection circuit is connected with the multi-stage power amplifier and is configured to receive and compare the power supply voltage and the reference voltage, and adjust the power supply voltage of at least one driving stage in the multi-stage power amplifier based on the comparison result of the power supply voltage and the reference voltage, so as to improve the reliability and the service life of the amplifier circuit.

Description

Technical Field

[0001] This disclosure relates to the field of integrated circuit technology, and in particular to an amplifier circuit, a radio frequency chip, and an electronic device. Background Technology

[0002] In mobile communication systems, radio frequency power amplifiers are a key component. Their main function is to amplify radio frequency signals and output power. Their performance and reliability directly affect the working efficiency of the entire transmission system.

[0003] In practical applications, radio frequency (RF) power amplifiers often face extreme scenarios such as high and low temperatures, high voltages, and antenna mismatch. Under these conditions, the operating state of the RF power amplifier can easily exceed the tolerance range of the power transistors, leading to device burnout and affecting the normal operation of the mobile communication system. Summary of the Invention

[0004] In view of this, embodiments of the present disclosure provide an amplifier circuit, an RF chip, and an electronic device to improve the reliability and lifespan of the amplifier circuit.

[0005] The technical solution of this disclosure embodiment is implemented as follows: This disclosure provides an amplifier circuit, including: a multi-stage power amplifier and a protection circuit; wherein the multi-stage power amplifier is configured to receive a radio frequency input signal and amplify the radio frequency input signal through multiple stages before outputting it; the protection circuit is connected to the multi-stage power amplifier and configured to receive and compare a power supply voltage and a reference voltage, and adjust the supply voltage of at least one driver stage in the multi-stage power amplifier based on the comparison result of the power supply voltage and the reference voltage; wherein the protection circuit includes: a comparator circuit and a voltage regulator circuit; the comparator circuit is configured to compare the power supply voltage and the reference voltage and generate a control current based on the comparison result; the voltage regulator circuit is connected to at least one driver stage in the multi-stage power amplifier and the comparator circuit, and configured to receive the control current and the power supply voltage, convert the power supply voltage into the supply voltage, and adjust the supply voltage based on the value of the control current.

[0006] In the above scheme, when the power supply voltage is greater than the reference voltage, the control current is inversely proportional to the power supply voltage; when the power supply voltage is less than or equal to the reference voltage, the control current is zero.

[0007] In the above scheme, the protection circuit is further configured to reduce the supply voltage of at least one driver stage in the multi-stage power amplifier based on the voltage difference between the supply voltage and the reference voltage when the supply voltage is greater than the reference voltage; wherein the voltage difference between the supply voltage and the reference voltage is inversely proportional to the voltage value of the supply voltage.

[0008] In the above scheme, the protection circuit is further configured to adjust the power supply voltage to a preset value when the power supply voltage is less than or equal to the reference voltage.

[0009] In the above scheme, the voltage regulator circuit includes at least one linear regulator; wherein, at least one of the linear regulators is configured to receive the control current and adjust the feedback voltage based on the control current.

[0010] In the above scheme, the comparison circuit includes: a first transistor, a second transistor, a first resistor, a constant current source, a first current source, and a second current source; wherein, the first terminal of the first transistor receives the reference voltage; the second terminal of the first transistor is connected to the first terminal of the constant current source; the control terminals of the first transistor and the second transistor are both connected to the second terminal of the first transistor; the first terminal of the first resistor receives the power supply voltage; the second terminal of the first resistor is connected to the first terminal of the second transistor; the second terminal of the second transistor is connected to the first terminal of the first current source and the first terminal of the second current source, respectively; the second terminals of the constant current source, the first current source, and the second current source are grounded.

[0011] In the above scheme, the linear regulator includes a third transistor and a first feedback resistor; wherein the third transistor and the first feedback resistor are connected in series and are both connected in parallel to the second current source.

[0012] In the above scheme, the linear regulator includes an operational amplifier and a second feedback resistor; wherein, the first input terminal of the operational amplifier receives the reference voltage; the second input terminal of the operational amplifier is connected to the second terminal of the first feedback resistor and the first terminal of the second feedback resistor; the output terminal of the operational amplifier is connected to the control terminal of the third transistor; the first terminal of the third transistor is connected to the first terminal of the second current source; the second terminals of the first and second feedback resistors are both connected to the second terminals of the second current source; the first terminal of the third transistor receives the power supply voltage; the second terminal of the third transistor is connected to the first terminal of the first feedback resistor; the second terminal of the third transistor outputs the power supply voltage; and the second terminal of the second feedback resistor is grounded.

[0013] This disclosure provides an RF chip, including the amplifier circuit described in any of the above embodiments.

[0014] This disclosure provides an electronic device including the radio frequency chip described above.

[0015] The protection circuit in this disclosure can adjust the supply voltage of at least one driver stage in a multi-stage power amplifier. Thus, in the event of excessive power supply voltage, the protection circuit can limit the output power of the driver stage of the multi-stage power amplifier by reducing the supply voltage of at least one driver stage. This prevents excessive output power from damaging the power transistors in the output stage of the power amplifier, greatly improving the reliability of the amplifier circuit and extending the service life of the entire transmission system. Attached Figure Description

[0016] Figure 1 A schematic diagram of the amplifier circuit provided in the embodiments of this disclosure. Figure 1 ; Figure 2 A schematic diagram of the amplifier circuit provided in the embodiments of this disclosure. Figure 2 ; Figure 3 This is a schematic diagram of the control current variation curve provided in an embodiment of the present disclosure; Figure 4 This is a schematic diagram of the power supply voltage variation curve provided in the embodiments of this disclosure; Figure 5 This is a schematic diagram of the output power variation curve provided in the embodiments of this disclosure; Figure 6 A schematic diagram of the amplifier circuit provided in the embodiments of this disclosure. Figure 3 ; Figure 7 A schematic diagram of the amplifier circuit provided in the embodiments of this disclosure. Figure 4 ; Figure 8 This is a schematic diagram of the structure of a linear voltage regulator provided in an embodiment of this disclosure; Figure 9 A schematic diagram of the structure of the comparison circuit provided in the embodiments of this disclosure; Figure 10 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this disclosure. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this disclosure are further described in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limitations on this disclosure. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0018] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0019] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to be limiting of this disclosure.

[0021] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0022] Figure 1 This is a schematic diagram of an optional amplifier circuit 100 provided in an embodiment of this disclosure, with reference to... Figure 1 It should be noted that, Figure 1 The power amplifiers 110 and 111 shown in the example are the driver stages of the multi-stage power amplifier 10, and the power amplifier 120 is the output stage of the multi-stage power amplifier 10. Figure 1 The number of power amplifiers in the multi-stage power amplifier 10 can also be an integer greater than or equal to 2. For example, the multi-stage power amplifier 10 can have 2, 3, 4 or 5 power amplifiers, etc. The embodiments of this application do not limit the number of power amplifiers in the multi-stage power amplifier 10.

[0023] In this embodiment of the disclosure, reference is made to Figure 1 The amplifier circuit 100 includes a multi-stage power amplifier 10. The multi-stage power amplifier 10 is configured to receive a radio frequency (RF) input signal and amplify it through multiple stages before outputting the signal. The input terminal RFIN of the multi-stage power amplifier 10 can receive the RF input signal, which is then amplified through multiple stages to generate an output signal. The output signal is then output along the output terminal RFOUT of the multi-stage power amplifier 10.

[0024] It should be noted that the reference Figure 1 The output power of the driver stages of the multi-stage power amplifier 10 (e.g., power amplifiers 110 and 111) is mainly controlled by two factors: supply voltage and load impedance. If the supply voltage of the driver stages of the multi-stage power amplifier 10 is too high, the driving capability of the driver stages of the multi-stage power amplifier 10 increases, resulting in excessively high overall output signal power of the driver stages of the multi-stage power amplifier 10. That is, the output stage (power amplifier 120) of the multi-stage power amplifier 10 receives excessively high signal power, which may damage the power transistors in the output stage of the multi-stage power amplifier 10.

[0025] In this embodiment of the disclosure, reference is made to Figure 1 The amplifier circuit 100 also includes a protection circuit 20. The protection circuit 20 is connected to the multi-stage power amplifier 10. The protection circuit 20 receives and compares the supply voltage and a reference voltage. The supply voltage provides the energy required for the amplifier circuit 100 to operate. The reference voltage can be the output voltage of a bandgap voltage reference circuit, which can serve as a high-precision voltage reference for detecting changes in the supply voltage. The reference voltage can also indirectly determine the maximum actual output power that the amplifier circuit 100 can output; for example, the reference voltage can limit the power of the amplifier circuit 100 by controlling parameters such as the bias voltage or supply voltage of the amplifier circuit 100.

[0026] In this embodiment of the disclosure, reference is made to Figure 1The protection circuit 20 is configured to adjust the supply voltage of at least one driver stage in the multi-stage power amplifier 10 based on a comparison result between the supply voltage and a reference voltage. The comparison result between the supply voltage and the reference voltage may include parameters such as the voltage difference and magnitude relationship between the supply voltage and the reference voltage. For example, the comparison result may be the magnitude relationship between the supply voltage and the reference voltage. When the supply voltage is greater than the reference voltage, the protection circuit 20 can reduce the supply voltage of at least one driver stage in the multi-stage power amplifier 10. When the supply voltage is less than or equal to the reference voltage, the protection circuit 20 can adjust the supply voltage of at least one driver stage in the multi-stage power amplifier 10 to a fixed preset value. In other words, this embodiment of the present disclosure can determine the magnitude of the supply voltage by comparing the reference voltage and the supply voltage. The protection circuit 20 adjusts the supply voltage of at least one driver stage in the multi-stage power amplifier 10 accordingly based on the magnitude of the supply voltage, thereby preventing overvoltage of the supply voltage of at least one driver stage in the multi-stage power amplifier 10.

[0027] It is understood that the protection circuit 20 in this embodiment can adjust the supply voltage of at least one driver stage in the multi-stage power amplifier 10. Thus, in the event of excessive power supply voltage, the protection circuit 20 can limit the output power of the driver stage of the multi-stage power amplifier 10 by reducing the supply voltage of at least one driver stage, thereby preventing damage to the power transistors of the output stage of the multi-stage power amplifier 10 due to excessive output power. This greatly improves the reliability of the amplifier circuit 100 and extends the service life of the entire transmission system.

[0028] In some embodiments of this disclosure, reference is made to Figure 1 The protection circuit 20 is also configured to reduce the supply voltage of at least one driver stage in the multi-stage power amplifier based on the voltage difference between the supply voltage and the reference voltage when the supply voltage is greater than the reference voltage. The voltage difference between the supply voltage and the reference voltage is inversely proportional to the supply voltage. That is, the larger the voltage difference between the supply voltage and the reference voltage, the greater the drop in supply voltage. The smaller the voltage difference between the supply voltage and the reference voltage, the smaller the drop in supply voltage, thus avoiding excessive interference with normal operation. In this way, the protection circuit 20 can automatically adjust the output supply voltage according to the fluctuation of the supply voltage. The inverse relationship between the voltage difference between the supply voltage and the reference voltage and the supply voltage allows the protection circuit 20 to automatically and smoothly respond to power voltage fluctuations, significantly improving the stability of the supply voltage. This prevents device damage that may be caused by overvoltage and reduces the risk of the load failing to operate normally due to excessive voltage regulation, thereby extending the service life of the entire transmission system.

[0029] In some embodiments of this disclosure, reference is made to Figure 1The protection circuit 20 is also configured to adjust the supply voltage to a preset value when the supply voltage is less than or equal to the reference voltage. The preset value can be determined during the design phase, and setting the supply voltage to the preset value ensures that the amplifier circuit 100 can perform its basic functions. In this way, the protection circuit 20 can actively clamp the output voltage to the preset value, thereby ensuring the basic operation of the amplifier circuit 100 under excessively high supply conditions, significantly improving the reliability of the amplifier circuit 100.

[0030] Figure 2 This is a schematic diagram of an optional amplifier circuit 100 provided in an embodiment of this disclosure. It should be noted that... Figure 1 The structures of power amplifiers 110, 111, and 120 in the text can be referenced. Figure 2 Let's understand Example 2. The capacitor C1 connected in series between power amplifiers 110 and 111, and the capacitor C2 connected in series between power amplifiers 111 and 120, are both DC blocking capacitors used to isolate DC voltage and prevent it from affecting the amplification process of the next stage amplifier. Power amplifier 110 may include inductor L1, a first amplifying transistor M21, and a second amplifying transistor M22. The control terminal (gate) of the second amplifying transistor M22 is the input terminal of amplifier circuit 100. Power amplifier 111 may include inductor L2, a third amplifying transistor M21, and a fourth amplifying transistor M22. Power amplifier 120 may include inductor L3, a first amplifying transistor M31, and a second amplifying transistor M32. The first terminal (source) of the fifth amplifying transistor M31 is the output terminal of amplifier circuit 100.

[0031] In some embodiments of this disclosure, reference is made to Figure 2 The protection circuit 20 includes a voltage regulator circuit 21. The voltage regulator circuit 21 is connected to at least one driver stage and a comparator circuit 22 in the multi-stage power amplifier 10. For example, as... Figure 2 As shown, the voltage regulator circuit 21 is connected to power amplifier 110 and power amplifier 111 in the multi-stage power amplifier 10, that is, multiple drive stages in the multi-stage power amplifier 10 are all connected to the same voltage regulator circuit 21.

[0032] In this embodiment of the disclosure, reference is made to Figure 2 The voltage regulator circuit 21 is configured to receive control current and power supply voltage V. BAT and the power supply voltage V BATThe voltage is converted to the supply voltage. For example, the voltage regulator circuit 21 may include a linear regulator (LDO) or a series transistor regulator circuit. The components of the voltage regulator circuit 21 may include a regulating transistor, a reference voltage source (such as a Zener diode or a bandgap reference circuit), and a voltage divider network (resistors). The reference voltage source typically provides a stable reference voltage. The voltage divider network samples the supply voltage through resistor division or other methods to generate a feedback voltage. The voltage regulator circuit 21 achieves voltage regulation by controlling the conduction level of the regulating transistor through negative feedback of the feedback voltage. In the case of a linear regulator circuit 21, the voltage regulator circuit 21 also utilizes the error amplifier in the linear regulator to compare the feedback voltage with the reference voltage and amplify the difference signal, thereby controlling the on-resistance of the regulating transistor.

[0033] Figure 3 , Figure 4 and Figure 5 The figures shown are schematic diagrams illustrating the performance parameter changes of amplifier circuit 100. It should be noted that... Figure 3 S1 in the example shows the power supply voltage V BAT The curve showing the change in control current ΔI; Figure 4 Example S2 in the diagram illustrates the power supply voltage V. BAT Greater than the reference voltage V REF Under these circumstances, control voltage V LDO The curve of change; Figure 4 Example S2 in the diagram illustrates the power supply voltage V. BAT Less than or equal to the reference voltage V REF Under these circumstances, control voltage V LDO The curve of change; Figure 5 Example S4 in the figure shows the output power variation curve when the amplifier circuit does not have the protection circuit 20 set; Figure 5 Example S5 shows the output power change curve when the amplifier circuit is equipped with protection circuit 20.

[0034] In some embodiments of this disclosure, reference is made to Figure 2 The protection circuit 20 includes a comparator circuit 22. The comparator circuit 22 is configured to compare the power supply voltage V. BAT and reference voltage V REF And based on the power supply voltage V BAT and reference voltage V REF The comparison result generates a control current. For example, comparator circuit 22 may include an operational transconductance amplifier (OTA). Comparator circuit 22 can convert the supply voltage V... BAT and reference voltage V REF The voltage difference is linearly converted into control current. For example... Figure 3 As shown, at power supply voltage VBAT Less than or equal to the reference voltage V REF Under these conditions, the control current ΔI output by comparator circuit 22 can always remain 0. Under the power supply voltage V... BAT Greater than the reference voltage V REF In the case of the comparator circuit 22 showing the power supply voltage V BAT It is proportional to the control current ΔI, as shown by curve S1.

[0035] In this embodiment of the disclosure, reference is made to Figure 2 The voltage regulator circuit 21 is also configured to adjust the supply voltage based on the value of the control current. For example, if the voltage regulator circuit 21 is a linear regulator, it can receive the control current output by the comparator circuit 22. Then, the voltage regulator circuit 21 adjusts its feedback voltage based on the control current, thereby adjusting its output supply voltage through changes in the feedback voltage. Figure 4 As shown, at power supply voltage V BAT Less than or equal to the reference voltage V REF Under these conditions, the control current ΔI output by the comparator circuit 22 can always remain at 0, and the supply voltage V output by the voltage regulator circuit 21 can be maintained at 0. LDO It can always remain at a preset value (e.g., 3.3V), as shown by curve S2. At the power supply voltage V... BAT Greater than the reference voltage V REF In this case, the power supply voltage VBAT shown by the comparator circuit 22 is proportional to the control current ΔI as shown by curve S1, and the power supply voltage V output by the voltage regulator circuit 21 is... LDO As shown in curve S2, it is related to the power supply voltage V. BAT They are inversely proportional. In this way, the protection circuit 20 can automatically adjust the output supply voltage according to the fluctuation of the power supply voltage, thereby preventing damage to the devices that may be caused by overvoltage, reducing the risk of the load failing to work properly due to excessive voltage regulation, and improving the service life of the entire transmission system.

[0036] In this embodiment of the disclosure, combined with Figure 2 and Figure 3 At power supply voltage V BAT Greater than the reference voltage V REF Under these conditions, the control current is related to the power supply voltage V. BAT Inversely proportional. That is, the protection circuit 20 can convert the voltage difference into a control current ΔI that is directly proportional to the voltage difference through the comparator circuit 22, thereby realizing the power supply voltage V BAT The voltage difference between the reference voltage and the supply voltage is inversely proportional to the supply voltage. At this time, the output power of the driver stage of amplifier circuit 100 changes as follows: Figure 5As shown in S5, compared to curve S4 without protection circuit, the peak-to-valley amplitude of the amplifier circuit's output power is reduced (i.e., the output fluctuation is reduced), which avoids overheating of the device caused by instantaneous overload, extends the life of the power amplifier tube, reduces the heat dissipation requirements, and improves the service life of the entire transmission system.

[0037] In this embodiment of the disclosure, combined with Figure 2 and Figure 3 At power supply voltage V BAT Less than or equal to the reference voltage V REF In this case, the control current ΔI is zero. Thus, the comparator circuit 22 will not affect the feedback voltage of the voltage regulator circuit 21, thereby ensuring the basic operation of the amplifier circuit 100.

[0038] Figure 6 and Figure 7 This is a schematic diagram of the optional amplifier circuit 100 provided in an embodiment of this disclosure. It should be noted that... Figure 6 and Figure 7 The first voltage regulator 211 shown in the example is used to regulate the supply voltage of the power amplifier 110, and the second voltage regulator 212 is used to regulate the supply voltage of the power amplifier 111. The voltage regulator circuit may also include a greater number of linear voltage regulators, which is not limited here. Figure 6 and Figure 7 Zhongyu Figure 2 The difference lies in the number of voltage regulators connected to comparator circuit 22 and the number of stages of the power amplifier; the remaining components can be referenced. Figure 2 The corresponding implementation examples will be understood and will not be repeated here.

[0039] Figure 8 This is a schematic diagram of an optional linear regulator 210 provided in an embodiment of this disclosure. Figure 6 and Figure 7 The structures of the first voltage regulator 211 and the second voltage regulator 212 in the above can be referenced. Figure 8 Use the examples to understand.

[0040] In some embodiments of this disclosure, reference is made to Figure 8 The linear regulator 210 includes an operational amplifier OP, a third transistor M3, a first feedback resistor R21, and a second feedback resistor R22.

[0041] In this embodiment of the disclosure, reference is made to Figure 8 The first input terminal of the operational amplifier OP receives the reference voltage V. REF The second input terminal of the operational amplifier OP is connected to the first feedback resistor R. 21 The second terminal and the second feedback resistor R 22 The first terminal, that is: the operational amplifier OP is connected to the first feedback resistor R.21 Second feedback resistor R 22 The connection node X is used. The output of the operational amplifier OP is connected to the control terminal (gate) of the third transistor M3.

[0042] In this embodiment of the disclosure, reference is made to Figure 8 The first terminal of the third transistor M3 receives the power supply voltage V. BAT The second terminal (drain) of the third transistor M3 is connected to the first feedback resistor R. 21 The first terminal. The second terminal of the third transistor M3, outputting the supply voltage V. LDO The second feedback resistor R 22 The second end is grounded.

[0043] In some embodiments of this disclosure, reference is made to Figure 8 The voltage regulator circuit includes at least one linear regulator 210. The at least one linear regulator 210 is configured to receive a control current ΔI and adjust the feedback voltage V of the linear regulator 210 based on the control current ΔI. FB .

[0044] In this embodiment of the disclosure, reference is made to Figure 8 The first terminal (source) of the third transistor M3 is connected to the first terminal of the second current source 215. The first feedback resistor R... 21 The second terminal and the second feedback resistor R 22 The first terminal of each current source 215 is connected to the second terminal of the second current source 215. That is, the second current source 215 is connected in parallel to the first feedback resistor R. 21 .

[0045] In this embodiment of the disclosure, reference is made to Figure 8 Power supply voltage V LDO The calculation method can be understood by referring to the formula (1) below.

[0046] (1).

[0047] It should be noted that in formula (1) For feedback voltage V FB .

[0048] Furthermore, combining various Figure 8 According to formula (1), the second current source 215 can control the feedback voltage V by outputting the control current. FB Therefore, the linear regulator 210 can be based on the feedback voltage V FB The change is used to adjust the output supply voltage V. LDO .

[0049] Figure 9 This is a schematic diagram of an optional comparison circuit 22 provided in an embodiment of this disclosure.

[0050] In some embodiments of this disclosure, reference is made to Figure 9 The comparator circuit 22 includes a first transistor M1, a second transistor M2, a first resistor R1, a constant current source 213, a first current source 214, and a second current source 215.

[0051] In this embodiment of the disclosure, reference is made to Figure 9 The first terminal (source) of the first transistor PM1 receives the reference voltage V. REF The second terminal of the first transistor PM1 is connected to the first terminal of the constant current source 213. The control terminals of both the first transistor PM1 and the second transistor PM2 are connected to the second terminal of the first transistor PM1. The first terminal of the first resistor R2 receives the power supply voltage V. BAT The second terminal of the first resistor R2 is connected to the first terminal of the second transistor PM2; the second terminal of the second transistor PM2 is connected to the first terminal of the first current source 214 and the first terminal of the second current source 215. The second terminals of the constant current source 213, the first current source 214, and the second current source 215 are grounded. The second current source 215 outputs a control current ΔI.

[0052] In this embodiment of the disclosure, reference is made to Figure 9 The current flowing through the first transistor PM1 and the current flowing through the second transistor PM2 in the comparator circuit 22 can be represented by the following formulas (2) and (3), respectively: (2).

[0053] (3).

[0054] It should be noted that in formulas (1) and (2) For the MOS channel carrier mobility, in formulas (1) and (2) For the threshold voltages of the first transistor PM1 and the second transistor PM2, in formulas (1) and (2) The capacitance per unit area of ​​the metal oxide layer in the MOSFET is given by formula (1). The gate-source voltage of the first transistor PM1 is given in formula (1). The gate-source voltage of the second transistor PM2 is given.

[0055] From the above formulas (1) and (2), the control current ΔI output by the second current source 215 can be calculated as shown in the following formula (4): (4).

[0056] It should be noted that formula (4) For the source voltage of PM1, formula (4) This is the source voltage of PM2.

[0057] Furthermore, since the two branches containing the first transistor PM1 and the second transistor PM2 form a current mirror-like effect, equation (4) can be simplified to equation (5) as shown below: (5).

[0058] In this embodiment of the disclosure, combined with Figure 9 And formula (5), at power supply voltage V BAT Less than or equal to the reference voltage V REF Under these conditions, the control current ΔI output by comparator circuit 22 can always remain 0. Under the power supply voltage V... BAT Greater than the reference voltage V REF In this case, the control current ΔI shown by the comparator circuit 22 is compared with the power supply voltage V. BAT It is directly proportional.

[0059] Figure 10 This is a schematic diagram of the structure of an electronic device 300 provided in an embodiment of the present disclosure, as shown below. Figure 10 As shown, the electronic device 300 includes a radio frequency (RF) chip 200. The RF chip 200 may include the amplifier circuit 100 shown in any of the above embodiments. The electronic device 300 may be any of the following: a server, a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a handheld computer, a desktop computer, a personal digital assistant, a portable media player, a smart speaker, a navigation device, a smartwatch, smart glasses, a smart necklace, or other wearable devices; a pedometer; a digital TV; a virtual reality (VR) terminal device; an augmented reality (AR) terminal device; a wireless terminal in industrial control; a wireless terminal in self-driving; a wireless terminal in remote medical surgery; a wireless terminal in a smart grid; a wireless terminal in transportation safety; a wireless terminal in a smart city; a wireless terminal in a smart home; a vehicle in a vehicle networking system; an in-vehicle device; an in-vehicle module; etc.

[0060] The sequence numbers of the embodiments disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The methods disclosed in the several method embodiments provided in this disclosure can be arbitrarily combined to obtain new method embodiments without conflict. The features disclosed in the several product embodiments provided in this disclosure can be arbitrarily combined to obtain new product embodiments without conflict. The features disclosed in the several method or device embodiments provided in this disclosure can be arbitrarily combined to obtain new method embodiments or device embodiments without conflict.

[0061] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An amplifier circuit, characterized by The application relates to an amplifier circuit. The amplifier circuit comprises: a multi-stage power amplifier and a protection circuit; wherein the multi-stage power amplifier is configured to receive a radio frequency input signal and output the radio frequency input signal after multi-stage amplification; the protection circuit is connected to the multi-stage power amplifier and is configured to receive and compare a power supply voltage and a reference voltage, and adjust a supply voltage of at least one driving stage in the multi-stage power amplifier based on a comparison result of the power supply voltage and the reference voltage; wherein the protection circuit comprises a comparison circuit and a voltage stabilizing circuit; the comparison circuit is configured to compare the power supply voltage and the reference voltage and generate a control current based on a comparison result; the voltage stabilizing circuit is connected to at least one driving stage in the multi-stage power amplifier and the comparison circuit, and is configured to receive the control current and the power supply voltage, convert the power supply voltage into the supply voltage, and adjust the supply voltage based on a value of the control current.

2. The amplifier circuit of claim 1, wherein in a case where the power supply voltage is greater than the reference voltage, the control current is inversely proportional to the power supply voltage; in a case where the power supply voltage is less than or equal to the reference voltage, the control current is zero.

3. The amplifier circuit of claim 1, wherein the protection circuit is further configured to, in a case where the power supply voltage is greater than the reference voltage, reduce the supply voltage of at least one driving stage in the multi-stage power amplifier based on a voltage difference between the power supply voltage and the reference voltage; wherein the voltage difference between the power supply voltage and the reference voltage is inversely proportional to a voltage value of the supply voltage.

4. The amplifier circuit of claim 1 or 3, wherein 5. The amplifier circuit of claim 1, wherein, the protection circuit is further configured to, in a case where the power supply voltage is less than or equal to the reference voltage, adjust the supply voltage to a preset value. the voltage stabilizing circuit comprises at least one linear voltage stabilizer; wherein 6. The amplifier circuit of claim 5, wherein, at least one linear voltage stabilizer is configured to receive the control current and adjust a feedback voltage thereof based on the control current. the comparison circuit further comprises a first transistor, a second transistor, a first resistor, a constant current source, a first current source and a second current source; wherein a first end of the first transistor receives the reference voltage; a second end of the first transistor is connected to a first end of the constant current source; a control end of the first transistor and a control end of the second transistor are both connected to the second end of the first transistor; a first end of the first resistor receives the power supply voltage; a second end of the first resistor is connected to a first end of the second transistor; a second end of the second transistor is respectively connected to a first end of the first current source and a first end of the second current source; 7. The amplifier circuit of claim 6, wherein, second ends of the constant current source, the first current source and the second current source are grounded. the linear voltage stabilizer comprises a third transistor and a first feedback resistor; wherein 8. The amplifier circuit of claim 7, wherein, the third transistor and the first feedback resistor are connected in series and are both connected in parallel to the second current source. the linear voltage stabilizer further comprises an operational amplifier and a second feedback resistor; wherein The first input end of the operational amplifier receives the reference voltage; the second input end of the operational amplifier is connected with the second end of the first feedback resistor and the first end of the second feedback resistor; and the output end of the operational amplifier is connected with the control end of the third transistor; The first end of the third transistor is connected with the first end of the second current source; and the second end of the first feedback resistor and the first end of the second feedback resistor are both connected with the second end of the second current source; The first end of the third transistor receives the power supply voltage; the second end of the third transistor is connected with the first end of the first feedback resistor; the second end of the third transistor outputs the supply voltage; and the second end of the second feedback resistor is grounded.

9. A radio frequency chip, characterized by The amplifier circuit comprises the amplifier circuit according to any one of claims 1-8.

10. An electronic device, comprising: The radio frequency chip comprises the amplifier circuit according to claim 9.

Images