Protection circuit of power amplifier and radio frequency power amplifier module

Abstract

The invention discloses a protection circuit of a power amplifier and a radio frequency power amplifier module. The protection circuit comprises a current limiting module used for being connected with a power supply and a power amplifier, and the current limiting module is used for detecting the current value of the power amplifier and generating a first control signal according to the difference between the current value and a preset current limit value; the first control signal is used for adjusting power supply current of the power supply to the power amplifier; the enabling control module is connected with the current limiting module, and the enabling control module is used for generating an enabling control signal according to the first control signal; the power conversion module is connected with the enabling control module and is used for adjusting the output voltage signal according to the enabling control signal; and the first amplification circuit is connected with the power supply conversion module, the first amplification circuit is used for being powered by the voltage signal and generating a driving signal, and the driving signal is used for adjusting the output power of the power amplifier. According to the technical scheme provided by the invention, current-limiting protection and power protection of the power amplifier can be realized.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of power amplifier design, and in particular to a protection circuit of a power amplifier and a radio frequency power amplifier module. Background Art

[0002] In the prior art, for the power supply of power amplifiers, the circuit power supply design includes two independent power supplies of 5V and 28V or some include a lower voltage power supply MCU. The power supply design is independent of each other and simply supplies power to small signal amplifiers and high power devices.

[0003] In the prior art, overpower is prone to cause the power amplifier and load resistor to burn out, and it is easy to cause the final stage power amplifier device to burn out and fail under the impact of a large input signal. Summary of the invention

[0004] The embodiments of the present invention provide a protection circuit for a power amplifier and a radio frequency power amplifier module to solve the problem that the existing power amplifier is burned due to overcurrent or overpower, thereby realizing overcurrent protection and overpower protection for the power amplifier.

[0005] In order to achieve the above technical problems, the present invention adopts the following technical solutions:

[0006] According to a first aspect of the present invention, there is provided a protection circuit for a power amplifier, comprising:

[0007] A current limiting module, used to connect the power supply and the power amplifier, the current limiting module is used to detect the current value of the power amplifier, and generate a first control signal according to the difference between the current current value and the preset current limit value; the first control signal is used to adjust the power supply current of the power supply to the power amplifier;

[0008] an enabling control module, connected to the current limiting module, and configured to generate an enabling control signal according to the first control signal;

[0009] A power conversion module, connected to the enable control module, and configured to adjust an output voltage signal according to the enable control signal;

[0010] The first amplifier circuit is connected to the power conversion module. The first amplifier circuit is used to be powered by the voltage signal and generate a drive signal. The drive signal is used to adjust the output power of the power amplifier.

[0011] Optionally, the current limiting module and the enabling control module are integrated into a protection chip, and the protection chip is hot-swappably connected to the power amplifier and the power supply.

[0012] Optionally, the current limiting module includes:

[0013] A current detection unit, the current detection unit is connected to the output end of the power amplifier, and the current detection unit is used to collect a voltage signal corresponding to a current current value of the power amplifier;

[0014] A control unit connected to the current detection unit, the control unit is used to charge the timer terminal when the voltage signal is greater than or equal to the clock reset voltage, and generate a first control signal when the voltage value of the timer terminal is greater than or equal to a preset trip threshold voltage;

[0015] The first control signal is used to control the power supply to be disconnected from the power amplifier, and to control the enable control module to be turned on or off, and to adjust the enable control signal output by the enable control module.

[0016] Optionally, the current detection unit includes a first resistor and a second resistor; the first end of the first resistor is connected to the output end of the main amplifier of the power amplifier, the second end of the first resistor is connected to the output end of the peak amplifier of the power amplifier and the first end of the second resistor, and the second end of the second resistor is connected to the load, and the current detection unit is used to determine the current current value of the power amplifier by collecting the voltage values ​​of the first resistor and the second resistor.

[0017] Optionally, the control unit includes:

[0018] A control chip, the control chip comprising a power input terminal, a sampling input terminal, a clock reset terminal, a timer terminal, a first switch tube and a power output terminal; the sampling input terminal is connected to the current detection unit, and the sampling input terminal is used to transmit a voltage signal corresponding to the current value of the power amplifier;

[0019] A third resistor connected to the sampling input terminal;

[0020] a fourth resistor connected to the clock reset terminal, wherein the operating current of the power amplifier is determined by the ratio of the fourth resistor to the third resistor; and the clock reset terminal is used to provide a clock reset voltage;

[0021] a first capacitor connected to the timer terminal, the control chip being used to charge the first capacitor when the voltage signal at the sampling input terminal is greater than or equal to the clock reset voltage at the clock reset terminal, and to generate a first control signal when the voltage value at the timer terminal is greater than or equal to a preset trip threshold voltage;

[0022] The control end of the first switch tube is used to receive the first control signal, the first pole of the first switch tube is connected to the power supply through the power input end, the second pole of the first switch tube is connected to the power amplifier through the power output end, and the first switch tube is used to shut down according to the first control signal.

[0023] Optionally, the enabling control module includes:

[0024] A switch unit, a first voltage dividing unit and a second voltage dividing unit;

[0025] The first end of the first voltage divider unit is connected to the alarm end of the control unit, and the alarm end is used to transmit the first control signal; the second end of the first voltage divider unit is connected to the control end of the switch unit, the third end of the first voltage divider unit is connected to the first end of the switch unit, the first end of the second voltage divider unit and the enable end of the power conversion module, the second end of the second voltage divider unit is connected to the power supply, and the third end of the second voltage divider unit is connected to the ground end; the second end of the switch unit is connected to the ground end;

[0026] The switch unit is used to be turned off when the first control signal is a first level signal, and the output enable control signal is a turn-off enable signal; and to be turned on when the first control signal is a second level signal, and the output enable control signal is a turn-on enable signal;

[0027] The shutdown enable signal is used to control the voltage signal output by the power conversion module to be a first voltage signal, and the conduction enable signal is used to control the power conversion module to output a second voltage signal; wherein, the first voltage signal is smaller than the second voltage signal.

[0028] Optionally, the switch unit includes a second switch tube, the first voltage dividing unit includes a fifth resistor and a sixth resistor, and the second voltage dividing unit includes a seventh resistor and an eighth resistor;

[0029] The first end of the fifth resistor is connected to the alarm end of the control unit, the second end of the fifth resistor is connected to the first end of the sixth resistor and the control end of the second switch tube, the first electrode of the second switch tube is connected to the second end of the sixth resistor, the first end of the seventh resistor, the first end of the eighth resistor and the enable end of the power conversion module, and the second electrode of the second switch tube is connected to the ground end;

[0030] The second end of the seventh resistor is connected to the power supply, and the second end of the eighth resistor is connected to the ground.

[0031] Optionally, the power conversion module includes:

[0032] A DC voltage step-down conversion chip, a first filtering unit and a second filtering unit;

[0033] The input end of the DC voltage step-down conversion chip is connected to the power supply through the first filtering unit, the enable end of the DC voltage step-down conversion chip is connected to the enable control module, and the output end of the DC voltage step-down conversion chip is connected to the power input end of the first amplifier circuit through the second filtering unit;

[0034] The first filtering unit and the second filtering unit are used for filtering, and the DC voltage step-down conversion chip is used to step down the power supply to the rated voltage of the first amplifier circuit.

[0035] Optionally, the first amplifying circuit includes:

[0036] A first stage signal amplifier and a second stage signal amplifier;

[0037] The input end of the first-stage signal amplifier is used to input a first-stage driving signal, the power supply end of the first-stage signal amplifier is connected to the output end of the power conversion module, the output end of the first-stage signal amplifier is connected to the input end of the second-stage signal amplifier, the power supply end of the second-stage signal amplifier is connected to the output end of the power conversion module, and the output end of the second-stage signal amplifier is used to output a driving signal;

[0038] The first-stage signal amplifier is used to amplify the first-stage driving signal, and the second-stage signal amplifier is used to amplify the amplified first-stage driving signal and output a driving signal;

[0039] The signal amplification power of the first amplifying circuit is smaller than the signal amplification power of the power amplifier.

[0040] According to a second aspect of the present invention, there is provided a radio frequency power amplifier module, comprising: a power amplifier and a protection circuit for the power amplifier provided by any embodiment of the present invention.

[0041] The protection circuit provided in the embodiment of the present invention adjusts the supply current of the power amplifier by detecting the difference between the current value of the power amplifier and the preset current limit value; at the same time, according to the difference between the current value of the power amplifier and the preset current limit value, the driving signal for the power amplifier is adjusted to adjust the output power of the power amplifier. Current limiting protection and over-power protection of the power amplifier are realized, the performance of the power amplifier is improved, and the phenomenon of over-power burning of high-power devices is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0043] Figure 1 is a schematic structural diagram of a protection circuit for a power amplifier provided by an embodiment of the present invention;

[0044] Figure 2 is a schematic structural diagram of another protection circuit for a power amplifier provided by an embodiment of the present invention;

[0045] Figure 3 is a schematic structural diagram of another protection circuit for a power amplifier provided by an embodiment of the present invention;

[0046] Figure 4 is a circuit diagram of a current limiting module provided by an embodiment of the present invention;

[0047] Figure 5 is a schematic structural diagram of another protection circuit for a power amplifier provided by an embodiment of the present invention;

[0048] Figure 6 is a circuit diagram of an enabling control module provided by an embodiment of the present invention;

[0049] Figure 7 It is a circuit diagram of a first amplifier circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0051] Based on the above technical problems, this embodiment proposes the following solutions:

[0052] Figure 1 FIG. 1 is a schematic diagram of a protection circuit for a power amplifier provided by an embodiment of the present invention. Figure 1As shown, the protection circuit 10 includes: a current limiting module 101, which is used to connect the power supply 20 and the power amplifier 30, and the current limiting module 101 is used to detect the current current value of the power amplifier 30, and generate a first control signal according to the difference between the current current value and the preset current limit value; the first control signal is used to adjust the power supply current from the power supply 20 to the power amplifier 30; an enable control module 102, which is connected to the current limiting module 101, and the enable control module 102 is used to generate an enable control signal according to the first control signal; a power conversion module 103, which is connected to the enable control module 102, and the power conversion module 103 is used to adjust the output voltage signal according to the enable control signal; a first amplifier circuit 104 is connected to the power conversion module 103, and the first amplifier circuit 104 is used to be powered by the voltage signal and generate a drive signal, and the drive signal is used to adjust the output power of the power amplifier 30.

[0053] The protection circuit of the power amplifier provided in the embodiment of the present invention provides current limiting protection and power protection for the power amplifier.

[0054] Among them, the current limiting module 101 is connected between the power supply 20 and the power amplifier 30. The current limiting module 101 detects the current value of the power amplifier 30 in real time. The detected current value is compared with the preset current limit. This preset current limit is set after comprehensive consideration based on the rated current of the power amplifier. If the current current value exceeds the preset current limit, it means that the power amplifier may be in an overload state and measures need to be taken to protect it.

[0055] Optionally, the maximum current consumption, that is, the preset current limit I can be calculated based on the relevant parameters of the power amplifier. LIMT For example, according to the following expression (1), the preset current limit value I is calculated: LIMT .

[0056]

[0057] Among them, I LIMT is the preset current limit, V CLREFNORM is the maximum voltage value of the clock reset terminal CLREF during normal operation, that is, the preset trip threshold voltage; G CS is the current sensing gain when the power FET is fully turned on, R CS is the current sensing resistor.

[0058] In the current limiting module, I LIMT It can be calculated according to the manual. According to the preset current limit I LIMTBased on formula (1), the preset trip threshold voltage is determined. The difference between the current current value and the preset current limit value can also be determined by comparing the currently sampled voltage value with the preset trip threshold voltage to generate the first control signal.

[0059] In combination with the above embodiment, once it is determined that the current of the power amplifier is overloaded, the current limiting module 101 generates a first control signal according to the difference between the current current value and the preset current limit value to adjust the output voltage and output current of the power supply 20 .

[0060] The protection circuit of the power amplifier provided in the embodiment of the present invention also includes regulation of the output power of the power amplifier. After the enable control module receives the first control signal, it generates an enable control signal to send to the power conversion module. The power conversion module adjusts the corresponding voltage signal according to the enable control signal. The first amplifier circuit may include a small signal amplifier circuit.

[0061] Exemplarily, the voltage signal is a power supply signal for the internal amplifier when the first amplifier circuit performs small signal amplification. According to the magnitude of the voltage signal, the first amplifier circuit generates a corresponding drive signal. The drive signal can further control the output power of the power amplifier, thereby achieving more sophisticated power protection.

[0062] The protection circuit of the power amplifier provided in the embodiment of the present invention adjusts the supply current of the power amplifier by detecting the difference between the current value of the power amplifier and the preset current limit. According to the difference between the current value of the power amplifier and the preset current limit, the driving signal for the power amplifier is adjusted to adjust the output power of the power amplifier. The protection circuit of the power amplifier provided in the embodiment of the present invention realizes current limiting protection and over-power protection for the power amplifier, improves the performance of the power amplifier, and avoids the phenomenon of over-power burning of high-power devices.

[0063] Optionally, based on the above embodiments, the current limiting module 101 and the enabling control module 102 are integrated into a protection chip, and the protection chip is hot-swappable with the power amplifier 30 and the power supply 20. This arrangement enables the protection chip to implement both overcurrent protection and overpower protection. The protection chip can be hot-swappable, thereby improving the application scenario and practicality of the protection chip.

[0064] Figure 2It is a structural schematic diagram of another protection circuit of a power amplifier provided by an embodiment of the present invention, wherein a current limiting module 101 includes: a current detection unit 1011, the current detection unit 1011 is connected to the output end of the power amplifier, and the current detection unit 1011 is used to collect a voltage signal corresponding to the current current value of the power amplifier; a control unit 1012 is connected to the current detection unit 1011, and the control unit 1012 is used to charge the timer end when the voltage signal is greater than or equal to the clock reset voltage, and generate a first control signal when the voltage value of the timer end is greater than or equal to the preset tripping threshold voltage; the first control signal is used to control the power supply to be disconnected from the power amplifier, and control the enable control module to be turned on or off, and adjust the enable control signal output by the enable control module.

[0065] Specifically, the current detection unit 1011 is set to monitor the output current of the power amplifier in real time and convert it into a corresponding voltage signal. This real-time monitoring mechanism can quickly capture abnormal changes in the current, so as to take timely measures for protection. When the voltage signal collected by the current detection unit is greater than or equal to the clock reset voltage, the control unit 1012 will start the timer for charging. When the voltage value at the timer end is greater than or equal to the preset trip threshold voltage, that is, after a certain delay, the first control signal is generated accordingly. The first control signal controls the disconnection of the power supply and the power amplifier and controls the on and off of the enable control module. The setting of the protection circuit of the power amplifier provided in the embodiment of the present invention solves the problem of over-current or over-power protection for the power amplifier; and the current detection unit 1011 achieves the effect of over-power amplifier current collection and over-jump prevention for the current sampling and delay of the power amplifier, avoiding the erroneous execution of the over-current or over-power protection operation generated by the protection circuit of the power amplifier when the over-power amplifier current is unstable.

[0066] Figure 3 FIG. 1 is a schematic diagram of another power amplifier protection circuit provided by an embodiment of the present invention. Figure 2 and Figure 3 The current detection unit 1011 of the protection circuit of the power amplifier provided in this embodiment includes a first resistor 106 and a second resistor 107. The first end of the first resistor 106 is connected to the output end of the main amplifier 104 of the power amplifier, the second end of the first resistor 106 is connected to the output end of the peak amplifier 305 of the power amplifier and the first end of the second resistor 107, and the second end of the second resistor 107 is connected to the load 308. The current detection unit 1011 is used to determine the current current value of the power amplifier by collecting the voltage values ​​of the first resistor 106 and the second resistor 107.

[0067] Optional, continue to see Figure 3The power amplifier includes: an input signal 301, a reference signal 302 separator 303, a peak amplifier 305, a main amplifier 304 and a load 308. The input signal 301 is a signal to be amplified by the power amplifier; the reference signal 302 is used for comparison with the input signal of the power amplifier. The separator 303 is used to separate the input signal and the reference signal in the power amplifier.

[0068] Specifically, the first resistor 106 in the current detection unit collects the output signal of the main amplifier 304 in the power amplifier; the second resistor 107 collects the total amplified signal in the power amplifier, and determines the current current value in each branch of the power amplifier respectively, so as to compare the difference between the collected current current value and the preset current value in the current limiting module, adjust the power supply current of the power supply and the power amplifier, and directly perform overcurrent protection on the power amplifier.

[0069] Figure 4 is a circuit diagram of a current limiting module provided by an embodiment of the present invention. Figure 4 , the current limiting module includes a control chip U1, a third resistor R3, a fourth resistor R4 and a first capacitor. The control chip U1 includes a power input terminal VIN, a sampling input terminal CS, a clock reset terminal CLREF, a timer terminal TIMER, a first switch tube and a power output terminal VOUT. The sampling input terminal CS is connected to the current detection unit, and the sampling input terminal CS is used to transmit a voltage signal corresponding to the current current value of the power amplifier. The third resistor R3 is connected to the sampling input terminal CS. The fourth resistor R4 is connected to the clock reset terminal CLREF, and the operating current of the power amplifier is determined by the ratio of the fourth resistor R4 to the third resistor R3; the clock reset terminal CLREF is used to provide a preset clock reset voltage. The first capacitor is connected to the timer terminal TIMER.

[0070] The control chip U1 is used to charge the first capacitor when the voltage signal of the sampling input terminal CS is greater than or equal to the clock reset voltage of the clock reset terminal CLREF. And generate a first control signal when the voltage value of the timer terminal TIMER is greater than or equal to the preset trip threshold voltage. The control end of the first switch tube is used to receive the first control signal, the first electrode of the first switch tube is connected to the power supply through the power input terminal VIN, the second electrode of the first switch tube is connected to the power amplifier through the power output terminal VOUT, and the first switch tube is used to shut down according to the first control signal.

[0071] Specifically, in the control chip U1, the sampling input terminal CS is connected to the third resistor R3 to collect the voltage signal of the corresponding part of the power amplifier. The voltage signal is compared with the clock reset voltage of the clock reset terminal CLREF. When the voltage signal is greater than or equal to the clock reset voltage, the first capacitor C1 is charged. At the same time, the timer terminal TIMER of the control chip U1 detects the voltage value in real time. When the voltage value of the timer terminal TIMER is greater than or equal to the preset trip threshold voltage, a first control signal is generated. At the same time, Figure 4 The control chip U1 shown also includes a first switch tube for receiving a first control signal. The first and second electrodes of the first switch tube are connected in series between the power input terminal VIN and the power output terminal VOUT. When the first control signal is at a first level, the first switch tube is disconnected, and the power input terminal VIN and the power output terminal VOUT of the control chip U1 are also disconnected.

[0072] like Figure 4 In the embodiment, the power input terminal VIN and the power output terminal VOUT in the control chip U1 are connected in series with the first power terminal EXT1 and the second power terminal EXT2, wherein the two power terminals are connected to the power supply and the power supply terminal of the power amplifier respectively. Optionally, when the first control signal is a second level signal, the first switch tube between the power input terminal VIN and the power output terminal VOUT in the control chip U1 is in a conducting state, and the power amplifier is powered normally.

[0073] When the first control signal is a first level signal, it means that the voltage value of the sampling input terminal CS is greater than or equal to the clock reset voltage, and because the voltage value of the timer terminal TIMER is greater than or equal to the preset trip threshold voltage, it means that the current value of the power amplifier collected is greater than the preset current value and has been for a period of time. Then after the first switch tube receives the first level signal, the switch tube is disconnected, and the power input terminal VIN and the power output terminal VOUT in the control chip U1 are disconnected, and the power supply and the power supply terminal of the power amplifier are disconnected at both ends of the first power supply terminal EXT1 and the second power supply terminal EXT2, and the power supply terminal of the power amplifier loses power supply. In this way, when the current current value of the power amplifier collected is greater than the preset current limit, the power supply of the power amplifier is adjusted to protect the power amplifier from overcurrent. Among them, the setting of the timer terminal TIMER of the control chip U1 also makes it possible to use the first switch tube to adjust the power supply current of the power amplifier after the current value of the power amplifier is too large for a certain period of time, so as to prevent misjudgment of the overcurrent state of the power amplifier.

[0074] Optionally, the preset current limit value may be a ratio of the fourth resistor R4 to the third resistor R3; illustratively, the resistance value of the fourth resistor R4 may be 133KΩ, and the resistance value of the third resistor R3 may be 15KΩ.

[0075] Optionally, the first capacitance value can be selected according to the required delay time; the exemplary first resistor C1 is 10nF. The control chip U1 of the control unit 1012 also includes an alarm terminal FAULT, which sends a first control signal EXT_PG to the enable control module 102 .

[0076] Figure 5 FIG. 1 is a schematic diagram of the structure of another protection circuit for a power amplifier provided by an embodiment of the present invention. Figure 5 As shown, the enabling control module 102 includes: a switch unit 1022, a first voltage dividing unit 1021 and a second voltage dividing unit 1023; the first end of the first voltage dividing unit 1021 is connected to the alarm end of the control unit 1012, and the alarm end is used to transmit a first control signal; the second end of the first voltage dividing unit 1021 is connected to the control end of the switch unit 1022, the third end of the first voltage dividing unit 1021 is connected to the first end of the switch unit 1022, the first end of the second voltage dividing unit 1023 and the enabling end of the power conversion module 103, and the second end of the second voltage dividing unit 1023 is connected to the power supply , the third end of the second voltage divider unit 1023 is connected to the ground end; the second end of the switch unit 1022 is connected to the ground end; the switch unit 1022 is used to turn off when the first control signal is a first level signal, and the output enable control signal is a shutdown enable signal; it is turned on when the first control signal is a second level signal, and the output enable control signal is a conduction enable signal; the shutdown enable signal is used to control the voltage signal output by the power conversion module 103 to be a first voltage signal, and the conduction enable signal is used to control the power conversion module 103 to output a second voltage signal; wherein, the first voltage signal is less than the second voltage signal.

[0077] Specifically, the enable control module 102 receives the first control signal generated by the control unit 1012 in the current limiting module 101 to control the enable terminal of the power conversion module 103. The power conversion module 103 converts the power to supply power to the first amplifier circuit 104.

[0078] Exemplarily, when the current signal collected by the current limiting module 101 is greater than the preset current value, the current limiting module 101 sends a first control signal which is a first level signal to the enable control module 102. After the switch unit 1022 in the enable control module 102 receives the first level signal, the switch unit 1022 is turned off, and a shutdown enable signal is sent to the power conversion chip, so that the voltage signal output by the power conversion module is a first voltage signal. Optionally, the first voltage signal is 0V, which means that the first amplifier circuit loses power supply, and the power amplifier loses the drive signal, thereby achieving over-power protection for the power amplifier.

[0079] Figure 61 is a circuit diagram of an enabling control module provided by an embodiment of the present invention. Figure 6 As shown, the switch unit 1022 may include a second switch tube Q2, the first voltage divider unit 1021 includes a fifth resistor R5 and a sixth resistor R6, and the second voltage divider unit 1023 includes a seventh resistor R7 and an eighth resistor R8; the first end of the fifth resistor R5 is connected to the alarm end of the control unit, the second end of the fifth resistor R5 is connected to the first end of the sixth resistor R6 and the control end of the second switch tube Q2, the first electrode of the second switch tube Q2 is connected to the second end of the sixth resistor R6, the first end of the seventh resistor R7, the first end of the eighth resistor R8 and the enable end of the power conversion module, and the second electrode of the second switch tube Q2 is connected to the ground end; the second end of the seventh resistor R7 is connected to the power supply, and the second end of the eighth resistor R8 is connected to the ground end.

[0080] Specifically, when the control chip U1 of the control unit 1012 in the current limiting module 101 sends an alarm signal EXT_PG to the enable control module 102, the switch unit 1022 in the enable control module 102 receives the alarm signal EXT_PG. The second switch tube Q2 is turned off under the control of the alarm signal EXT_PG, and the enable control signal output to the power conversion module is a shutdown enable signal. At this time, the voltage output by the power conversion module is a first voltage signal. Optionally, the first voltage signal cannot provide a drive signal for the power amplifier circuit. When the switch unit 1022 in the enable control module 102 does not receive the alarm signal EXT_PG, the enable control signal output by the second switch tube Q2 is a conduction signal. After the enable end of the power conversion module receives the conduction signal, the output voltage signal is a second voltage signal. The optional second voltage signal can provide a drive signal for the power amplifier circuit.

[0081] Optionally, the fifth resistor R5 is 10KΩ; the sixth resistor R6 may be 0Ω; the seventh resistor R7 and the eighth resistor R8 may not be set.

[0082] In combination with the above embodiments, Figure 6 As shown, the power conversion module 103 may include: a DC voltage step-down conversion chip 1032, a first filtering unit 1031 and a second filtering unit 1033; the input end of the DC voltage step-down conversion chip 1032 is connected to the power supply through the first filtering unit 1031, the enable end of the DC voltage step-down conversion chip 1032 is connected to the enable control module, and the output end of the DC voltage step-down conversion chip 1032 is connected to the power input end of the first amplifier circuit through the second filtering unit 1033; the first filtering unit 1031 and the second filtering unit 1033 are used for filtering, and the DC voltage step-down conversion chip 1032 is used to step down the power supply to the rated voltage of the first amplifier circuit.

[0083] Specifically, the voltage signal passes through the third power supply terminal EXT3, is filtered by the first filtering unit 1031, is stepped down by the DC voltage step-down conversion chip 1032, is filtered again by the second filtering unit 1033, and is sent to the first amplifier circuit 104 through the fourth power supply terminal EXT4, which is used to power the first amplifier circuit 104 for small signal amplification. Optionally, the voltage signal of the third power supply terminal EXT3 is 48V, and the voltage signal of the fourth power supply terminal EXT4 is 5V. Among them, the enable control module 102 enables the enable control terminal EN of the DC voltage step-down conversion chip 1032. When the enable control terminal EN of the DC voltage step-down conversion chip 1032 receives a conduction signal, the DC voltage step-down conversion chip 1032 performs the step-down function normally and outputs the second voltage signal; and when the enable control terminal EN of the DC voltage step-down conversion chip 1032 receives a shutdown signal, the DC voltage step-down conversion chip 1032 stops the step-down function and outputs the first voltage signal.

[0084] Figure 7 is a circuit diagram of a first amplifier circuit provided by an embodiment of the present invention, such as Figure 7 As shown, the first amplifier circuit may include: a first-stage signal amplifier 1041 and a second-stage signal amplifier 1042; the input end of the first-stage signal amplifier 1041 is used to input a first-stage drive signal, the power supply end of the first-stage signal amplifier 1041 is connected to the output end EXT4 of the power conversion module, the output end of the first-stage signal amplifier 1041 is connected to the input end of the second-stage signal amplifier 1042, the power supply end of the second-stage signal amplifier 1042 is connected to the output end EXT4 of the power conversion module, and the output end of the second-stage signal amplifier 1042 is used to output a drive signal; the first-stage signal amplifier 1041 is used to amplify the first-stage drive signal, and the second-stage signal amplifier 1042 is used to amplify the amplified first-stage drive signal and output the drive signal; the signal amplification power of the first amplifier circuit is less than the signal amplification power of the power amplifier.

[0085] Specifically, the first-stage signal amplifier 1041 and the second-stage signal amplifier 1042 include a first RF amplifier RF1 and a second RF amplifier RF2 to amplify the input signal in the input terminal EXT7 of the first amplifier circuit twice, and send it to the power amplifier through the output terminal EXT8 of the first amplifier circuit. The first amplifier circuit provides a driving signal for the power amplifier.

[0086] Optionally, the first amplifier circuit can be a small signal amplifier circuit. The first-stage signal amplifier 1041 also includes a power supply terminal EXT5, and the second-stage signal amplifier 1042 also includes a power supply terminal EXT6. The two power supply terminals are connected to the output terminal EXT4 of the power conversion module. In combination with the above-mentioned embodiment, when the current limiting module 101 detects that the current current value of the power amplifier is greater than or equal to the preset current limit, the first control signal EXT_PG is output to the enable control module 102, and the enable control module 102 controls the power conversion module 105 to output the first voltage signal according to the first control signal EXT_PG. Optionally, the first voltage signal is 0V at this time. Then the power signal received by the power supply terminal of the first-stage signal amplifier 1041 and the second-stage signal amplifier 1042 is also 0V. The first amplifier circuit cannot perform two-stage amplification of the signal, and the power amplifier cannot obtain the drive signal. In this way, when it is detected that the current current value of the power amplifier is greater than or equal to the preset current limit, the power drive signal is no longer provided to the power amplifier, thereby realizing over-power protection for the power amplifier.

[0087] Table 1 is a comparison table of shutdown current and shutdown power corresponding to different parameters of the power amplifier.

[0088]

[0089] Comparison table of shutdown current and shutdown power corresponding to different parameters of power amplifier

[0090] In combination with the above embodiments, in the above Table 1, the quiescent current refers to the current value consumed by the RF power amplifier module after it is powered on when the power amplifier 30 is turned off, and is the basic current consumption when the RF power amplifier module does not perform any signal amplification. In the above Table 1, the basic current refers to the current value consumed by the RF power amplifier module as a whole when the power amplifier 30 is in the on state, including the current of the normal operation of the power amplifier 30 and the current consumption of the protection circuit of the power amplifier. In the above Table 1, the full-power enabling current refers to the current value required to enable the power amplifier 30 when the power amplifier 30 outputs at full power (output power is 46dBm). In the above Table 1, the shutdown current refers to the current value when a sudden high-power signal is input to the power amplifier when the power amplifier 30 is in the on state, but the power amplifier is still in the on state, but is about to be shut down. In the above Table 1, the signal source power refers to the signal source output power value when the power amplifier 30 is in the on state and a sudden high-power signal is input to the power amplifier, so that the power amplifier is shut down after over-power protection. In the above Table 1, the shutdown power is the maximum output power value that can be output when the power amplifier is shut down after the protection circuit protects the power amplifier.

[0091] It can be seen from Table 1 that for the first and second group of parameters, when the quiescent current and the basic current are the same, when the signal source power is different, the full-power enable current of the one with a larger signal source power will be smaller, but the shutdown current and shutdown power will be larger. For the first and third group of parameters, when the signal source power decreases, the shutdown current will be larger, and the shutdown power will be smaller. For the first and fourth group of parameters, when the signal source power, quiescent current and basic current are the same, the larger the full-power enable current, the larger the corresponding shutdown current, and the smaller the shutdown power. For the first and third group of parameters, when the signal source power decreases, the shutdown current will be larger, and the shutdown power will be smaller.

[0092] On the basis of the above embodiments, the RF power amplifier module may include a power amplifier and a protection circuit. The RF power amplifier module may be hot-swappable with the control device. A power supply and / or a control module for the RF power amplifier module may be provided in the control device. A card slot is provided on the control device, and the RF power amplifier module is provided with a connection port corresponding to the card slot of the control device. The power amplifier and the protection circuit may also be hot-swappable.

[0093] Specifically, by setting up a hot-swap connection between the RF power amplifier module and the control device, as well as a hot-swap connection between the power amplifier and the protection circuit, technicians are allowed to directly replace faulty modules or modules that need to be upgraded during system operation without shutting down the entire RF power amplifier module or control device, thereby reducing maintenance time, improving maintenance efficiency, and reducing the risk of instability of the RF power amplifier module due to restart.

[0094] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A protection circuit for a power amplifier, characterized in that: include: A current limiting module, used to connect the power supply and the power amplifier, the current limiting module is used to detect the current value of the power amplifier, and generate a first control signal according to the difference between the current current value and the preset current limit value; the first control signal is used to adjust the power supply current of the power supply to the power amplifier; an enabling control module, connected to the current limiting module, and configured to generate an enabling control signal according to the first control signal; A power conversion module, connected to the enable control module, and configured to adjust an output voltage signal according to the enable control signal; The first amplifier circuit is connected to the power conversion module. The first amplifier circuit is used to be powered by the voltage signal and generate a drive signal. The drive signal is used to adjust the output power of the power amplifier.

2. The protection circuit according to claim 1, characterized in that: The current limiting module and the enabling control module are integrated into a protection chip, and the protection chip is hot-swappably connected to the power amplifier and the power supply.

3. The protection circuit according to claim 1, characterized in that: The current limiting module comprises: A current detection unit, the current detection unit is connected to the output end of the power amplifier, and the current detection unit is used to collect a voltage signal corresponding to a current current value of the power amplifier; A control unit connected to the current detection unit, the control unit is used to charge the timer terminal when the voltage signal is greater than or equal to the clock reset voltage, and generate a first control signal when the voltage value of the timer terminal is greater than or equal to a preset trip threshold voltage; The first control signal is used to control the power supply to be disconnected from the power amplifier, and to control the enable control module to be turned on or off, and to adjust the enable control signal output by the enable control module.

4. The protection circuit according to claim 3, characterized in that: The current detection unit includes a first resistor and a second resistor; the first end of the first resistor is connected to the output end of the main amplifier of the power amplifier, the second end of the first resistor is connected to the output end of the peak amplifier of the power amplifier and the first end of the second resistor, and the second end of the second resistor is connected to the load. The current detection unit is used to determine the current current value of the power amplifier by collecting the voltage values ​​of the first resistor and the second resistor.

5. The protection circuit according to claim 3, characterized in that: The control unit comprises: A control chip, the control chip comprising a power input terminal, a sampling input terminal, a clock reset terminal, a timer terminal, a first switch tube and a power output terminal; the sampling input terminal is connected to the current detection unit, and the sampling input terminal is used to transmit a voltage signal corresponding to the current value of the power amplifier; A third resistor connected to the sampling input terminal; a fourth resistor connected to the clock reset terminal, wherein the operating current of the power amplifier is determined by the ratio of the fourth resistor to the third resistor; the clock reset terminal is used to provide a clock reset voltage; a first capacitor connected to the timer terminal, the control chip being used to charge the first capacitor when the voltage signal at the sampling input terminal is greater than or equal to the clock reset voltage at the clock reset terminal, and to generate a first control signal when the voltage value at the timer terminal is greater than or equal to a preset trip threshold voltage; The control end of the first switch tube is used to receive the first control signal, the first pole of the first switch tube is connected to the power supply through the power input end, the second pole of the first switch tube is connected to the power amplifier through the power output end, and the first switch tube is used to shut down according to the first control signal.

6. The protection circuit according to any one of claims 3 to 5, characterized in that: The enabling control module comprises: A switch unit, a first voltage dividing unit and a second voltage dividing unit; The first end of the first voltage divider unit is connected to the alarm end of the control unit, and the alarm end is used to transmit the first control signal; the second end of the first voltage divider unit is connected to the control end of the switch unit, the third end of the first voltage divider unit is connected to the first end of the switch unit, the first end of the second voltage divider unit and the enable end of the power conversion module, the second end of the second voltage divider unit is connected to the power supply, and the third end of the second voltage divider unit is connected to the ground end; the second end of the switch unit is connected to the ground end; The switch unit is used to be turned off when the first control signal is a first level signal, and the output enable control signal is a turn-off enable signal; and to be turned on when the first control signal is a second level signal, and the output enable control signal is a turn-on enable signal; The shutdown enable signal is used to control the voltage signal output by the power conversion module to be a first voltage signal, and the conduction enable signal is used to control the power conversion module to output a second voltage signal; wherein, the first voltage signal is smaller than the second voltage signal.

7. The protection circuit according to claim 6, characterized in that: The switch unit includes a second switch tube, the first voltage dividing unit includes a fifth resistor and a sixth resistor, and the second voltage dividing unit includes a seventh resistor and an eighth resistor; The first end of the fifth resistor is connected to the alarm end of the control unit, the second end of the fifth resistor is connected to the first end of the sixth resistor and the control end of the second switch tube, the first electrode of the second switch tube is connected to the second end of the sixth resistor, the first end of the seventh resistor, the first end of the eighth resistor and the enable end of the power conversion module, and the second electrode of the second switch tube is connected to the ground end; The second end of the seventh resistor is connected to the power supply, and the second end of the eighth resistor is connected to the ground.

8. The protection circuit according to claim 1, characterized in that: The power conversion module comprises: A DC voltage step-down conversion chip, a first filtering unit and a second filtering unit; The input end of the DC voltage step-down conversion chip is connected to the power supply through the first filtering unit, the enable end of the DC voltage step-down conversion chip is connected to the enable control module, and the output end of the DC voltage step-down conversion chip is connected to the power input end of the first amplifier circuit through the second filtering unit; The first filtering unit and the second filtering unit are used for filtering, and the DC voltage step-down conversion chip is used to step down the power supply to the rated voltage of the first amplifier circuit.

9. The protection circuit according to claim 1, characterized in that: The first amplifying circuit comprises: A first stage signal amplifier and a second stage signal amplifier; The input end of the first-stage signal amplifier is used to input a first-stage driving signal, the power supply end of the first-stage signal amplifier is connected to the output end of the power conversion module, the output end of the first-stage signal amplifier is connected to the input end of the second-stage signal amplifier, the power supply end of the second-stage signal amplifier is connected to the output end of the power conversion module, and the output end of the second-stage signal amplifier is used to output a driving signal; The first-stage signal amplifier is used to amplify the first-stage driving signal, and the second-stage signal amplifier is used to amplify the amplified first-stage driving signal and output a driving signal; The signal amplification power of the first amplification circuit is smaller than the signal amplification power of the power amplifier.

10. A radio frequency power amplifier module, characterized in that: include: A power amplifier and a protection circuit for the power amplifier as claimed in any one of claims 1 to 9.

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