[go: up one dir, main page]

WO2024250662A1 - 一种保护电路及放大电路 - Google Patents

一种保护电路及放大电路 Download PDF

Info

Publication number
WO2024250662A1
WO2024250662A1 PCT/CN2024/070232 CN2024070232W WO2024250662A1 WO 2024250662 A1 WO2024250662 A1 WO 2024250662A1 CN 2024070232 W CN2024070232 W CN 2024070232W WO 2024250662 A1 WO2024250662 A1 WO 2024250662A1
Authority
WO
WIPO (PCT)
Prior art keywords
transistor
circuit
current
electrically connected
filter
Prior art date
Application number
PCT/CN2024/070232
Other languages
English (en)
French (fr)
Inventor
彭振飞
陆航
Original Assignee
尚睿微电子（上海）有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 尚睿微电子（上海）有限公司 filed Critical 尚睿微电子（上海）有限公司
Publication of WO2024250662A1 publication Critical patent/WO2024250662A1/zh

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H03F1/301—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters in MOSFET amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/08—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers

Definitions

  • the present disclosure is based on the Chinese patent application with application number 202310682633.4, application date June 9, 2023, and application name “A protection circuit and an amplifier circuit”, and claims the priority of the Chinese patent application.
  • the entire contents of the Chinese patent application are hereby introduced into the present disclosure as a reference.
  • the present disclosure relates to but is not limited to the field of analog integrated circuit technology, and in particular to a protection circuit and an amplifier circuit.
  • the existing technology often directly detects the temperature of power devices, such as using temperature-sensitive devices such as thermistors or transistors to sample the temperature, and converting the temperature signal into an electrical signal that is easy to process, thereby achieving a rapid response to temperature changes and protecting the power devices.
  • temperature-sensitive devices such as thermistors or transistors
  • the transistor cannot be integrated in the filter, so the temperature of the filter cannot be directly detected, and the thermistor has low sensitivity, and the detection accuracy is difficult to guarantee.
  • the traditional power amplifier module since the collector of the transistor is directly connected to the power supply, the traditional power amplifier module cannot integrate a protection circuit. Therefore, the traditional power amplifier module cannot protect the filter.
  • the embodiments of the present disclosure provide a protection circuit and an amplifier circuit.
  • the embodiment of the present disclosure provides a protection circuit, the protection circuit is used to be electrically connected to a power amplifier, and the power amplifier is electrically connected to a filter;
  • the protection circuit at least includes a filter analog circuit, a reference voltage circuit, a comparator and a current mirror circuit;
  • the comparator at least includes a first input terminal, a second input terminal and a comparison output terminal;
  • the filter simulation circuit is electrically connected to the first input terminal, and the filter simulation circuit is used to simulate the current of the filter and output a filter voltage related to the filter temperature;
  • the reference voltage circuit is electrically connected to the second input terminal, and the reference voltage circuit is used to output a reference voltage related to the ambient temperature;
  • the current mirror circuit is electrically connected to the comparison output terminal, the power amplifier and the filter simulation circuit respectively, and the current mirror circuit is used to provide a first input current for the power amplifier; the filter simulation circuit is used to obtain a second input current for simulating the filter current according to the first input current;
  • the comparator is used for controlling the current mirror circuit to change the magnitudes of the first input current and the second input current according to the filter voltage and the reference voltage, so as to control the temperature of the filter.
  • the embodiment of the present disclosure provides an amplifier circuit, the amplifier circuit is connected to the above-mentioned protection circuit, the amplifier circuit at least includes the power amplifier; the power amplifier at least includes a bias circuit and an amplifier transistor;
  • One end of the bias circuit is electrically connected to the second end of the second transistor in the current mirror circuit, and the other end of the bias circuit is electrically connected to the third end of the amplifying transistor;
  • the emitter of the amplifying transistor is grounded, and the collector of the amplifying transistor is electrically connected to the filter;
  • the first input current is used to feed the bias circuit
  • the power amplifier is used to amplify the first input current and input the amplified first input current to the filter.
  • An embodiment of the present disclosure provides a radio frequency chip, wherein the radio frequency chip includes the above-mentioned protection circuit.
  • An embodiment of the present disclosure provides an electronic device, which includes the above-mentioned protection circuit or radio frequency chip.
  • the protection circuit and amplifier circuit provided by the embodiments of the present disclosure, firstly, by comparing the filter voltage related to the filter temperature and the reference voltage related to the ambient temperature, the current flowing through the filter is changed and the power output of the power amplifier is adjusted.
  • the embodiments of the present disclosure link the current and the filter temperature together according to the linear relationship between power and current, thereby realizing temperature monitoring of the filter, and then protecting the filter through the protection circuit;
  • the present disclosure directly samples the electrical signal and uses the resistance of the filter to indirectly monitor the filter temperature, thereby protecting the power module, without integrating a temperature detection element in the filter, which not only reduces the cost but also reduces the size of the filter.
  • FIG1 is a schematic diagram of the structure of a power amplifier module in the related art
  • FIG2 is a schematic diagram of a structure of a protection circuit and an amplifier circuit provided in an embodiment of the present disclosure
  • FIG3 is another schematic diagram of the structure of the protection circuit and the amplifier circuit provided by the embodiment of the present disclosure.
  • FIG4 is a schematic diagram of the structure of a current mirror circuit provided in an embodiment of the present disclosure.
  • FIG5 is a schematic diagram of the structure of a filter simulation circuit provided by an embodiment of the present disclosure.
  • FIG6 is a schematic diagram of the structure of a protection circuit and an amplifier circuit provided in an embodiment of the present disclosure
  • FIG7 is a schematic diagram showing the relationship between the critical power and the ambient temperature of the filter provided by an embodiment of the present disclosure
  • FIG8 is a schematic diagram of the relationship between the critical temperature of the filter provided by an embodiment of the present disclosure and the ambient temperature.
  • FIG1 is a schematic diagram of the structure of a power amplifier module in the related art.
  • the power amplifier module in the related art at least includes a bias circuit 101, a matching circuit 102 and an amplifying transistor Q4, wherein the collector of the transistor Q3 in the bias circuit 101 is directly connected to the power supply VDD, so that the power amplifier module in the related art cannot integrate a protection circuit, and therefore cannot protect the filter.
  • FIG2 is a schematic diagram of the structure of the protection circuit and the amplifier circuit provided by the embodiment of the present disclosure.
  • the protection circuit 20 is electrically connected to the power amplifier 10, and the power amplifier 10 is electrically connected to the filter 30.
  • the protection circuit 20 at least includes a filter simulation circuit 201, a reference voltage circuit 202, a comparator COMP and a current mirror circuit 203; the comparator at least includes a first input terminal 1, a second input terminal 2 and a comparison output terminal out1.
  • the filter simulation circuit 201 is electrically connected to the first input terminal 1, and is used to simulate the current of the filter 30 and output a filter voltage V SNS related to the temperature of the filter 30;
  • the reference voltage circuit 202 is electrically connected to the second input terminal 2, and is used to output a reference voltage V REF related to the ambient temperature;
  • the current mirror circuit 203 is electrically connected to the comparison output terminal out1, the power amplifier 10 and the filter simulation circuit 201 respectively, and is used to provide a first input current I HBT for the power amplifier 10, and the filter simulation circuit 201 is used to obtain a second input current I 2 for simulating the filter current according to the first input current I HBT ;
  • the comparator COMP is used to control the current mirror circuit 203 to change the size of the first input current I HBT according to the filter voltage V SNS and the reference voltage V REF , thereby adjusting the power of the power amplifier to control the temperature of the filter 30, wherein the second input current I 2 changes with I HBT .
  • the filter analog circuit 201 has a critical temperature; when the temperature of the filter analog circuit 201 is greater than or equal to the critical temperature, the current mirror circuit is used to limit the current values of the first input current I HBT and the second input current I 2 to be less than a preset current value to limit the power of the power amplifier 10 and the filter 30 to control the temperature of the filter 30.
  • the voltage of the filter 30 is greater than a reference voltage.
  • the embodiment of the present disclosure changes the current flowing through the filter and adjusts the power output of the power amplifier by comparing the filter voltage related to the filter temperature and the reference voltage related to the ambient temperature.
  • the present disclosure links the current and the filter temperature together based on the linear relationship between power and current, thereby realizing temperature monitoring of the filter and further protecting the filter.
  • the present disclosure directly samples the electrical signal and uses the resistance of the filter to indirectly monitor the filter temperature, thereby protecting the power module. There is no need to integrate a temperature detection element in the filter, which reduces both the cost and the size of the filter.
  • the current mirror circuit 203 at least includes a control transistor MN1 , a first current source I LIMIT and a current mirror unit.
  • the circuit further includes an inverter, which is electrically connected to the comparison output terminal out1 and the current mirror circuit 203 respectively.
  • the first end of the control transistor MN1 is electrically connected to the current mirror unit, and the second end of the control transistor MN1 is electrically connected to the current mirror unit.
  • the first current source I LIMIT is connected to the ground, and the third end of the control transistor MN1 is electrically connected to the output end out1 of the comparator COMP through an inverter, and the control transistor MN1 is used to adjust the size of the first input current I HBT .
  • the positive electrode of the first current source I LIMIT is electrically connected to the current mirror unit and the first end of the control transistor MN1, respectively, and the negative electrode of the first current source I LIMIT is grounded.
  • the first current source I LIMIT is used to cooperate with the control transistor MN1 to adjust the size of the first input current I HBT and the second input current I 2 .
  • FIG. 4 is a schematic diagram of the structure of a current mirror circuit provided by an embodiment of the present disclosure.
  • the current mirror unit at least includes a first transistor MP1 and a second transistor MP2.
  • the first end of the transistor is the source of the transistor
  • the second end of the transistor is the drain of the transistor
  • the third end of the transistor is the gate of the transistor.
  • the transistor may also be a triode, etc., which is not limited here.
  • the first ends of the first transistor MP1 and the second transistor MP2 are electrically connected to the power supply VDD; the second end of the first transistor MP1 is electrically connected to the first end of the control transistor MN1, the second end of the control transistor MN1 is grounded, and the third end of the control transistor MN1 is electrically connected to the comparison output end out1 of the comparator COMP through the inverter inverter; the third end of the first transistor MP1 is electrically connected to the first control port A, the third end of the second transistor MP2, and the positive electrode of the first current source I LIMIT respectively; the second end of the second transistor MP2 is electrically connected to the power amplifier 10 for outputting the first input current I HBT , wherein the first transistor MP1 and the second transistor MP2 form a first current mirror circuit so that the first input current I HBT is proportional to the output current of the first transistor MP1, so that the first input current I HBT and the second input current I 2 are adjusted by adjusting the output current of the first transistor
  • the control transistor MN1 when the temperature of the filter simulation circuit 201 is greater than or equal to the critical temperature, the control transistor MN1 is turned off, and the current of the first transistor MP1 is limited to the current of the first current source I LIMIT , thereby limiting the current values of the first input current I HBT and the second input current I 2.
  • the control transistor MN1 When the temperature of the filter simulation circuit 201 is less than the critical temperature, the control transistor MN1 is turned on, and the current of the first transistor MP1 is the sum of the current of the control transistor MN1 and I LIMIT .
  • the filter simulation circuit 201 includes a current simulation module and a thermal resistance simulation module R1 .
  • the current simulation module is connected to the thermal resistance simulation module R1 .
  • the thermal resistance simulation module R1 is used to simulate the thermal resistance of the filter 30 .
  • the current simulation module includes a third transistor MP3 and a second current source I QC .
  • a first end of the third transistor MP3 is electrically connected to a power supply VDD, a second end of the third transistor MP3 is electrically connected to the thermal resistance simulation module, a third end of the third transistor MP3 is electrically connected to a first control port A of a current mirror circuit, and a magnitude of the second input current I 2 is determined by an output current I 3 of the third transistor MP3 and the second current source I QC , wherein the output current I 3 of the third transistor MP3 is proportional to the first input current I HBT of the current mirror circuit.
  • a first terminal of the third transistor MP3 is electrically connected to a power source VDD
  • a second terminal of the third transistor MP3 is electrically connected to a thermal resistance simulation module R1
  • a third terminal of the third transistor MP3 is electrically connected to a first control port A.
  • the first transistor MP1 and the third transistor MP3 form a second current mirror circuit to control the current I HBT of the second transistor MP2 to be proportional to the current I 3 of the third transistor MP3.
  • the current simulation module further includes an operational amplifier OPMAP and a fourth transistor MP4, as shown in FIG5, which is a schematic diagram of the structure of the filter simulation circuit provided by an embodiment of the present disclosure.
  • the operational amplifier OPMAP includes a third input terminal 3, a fourth input terminal 4 and an operational amplifier output terminal out2; the second end of the second transistor MP2 and the second end of the third transistor MP3 in the current mirror circuit 203 are electrically connected to the third input terminal 3 and the fourth input terminal 4 of the operational amplifier OPAMP, respectively, and the operational amplifier controls the second end voltage of the second transistor MP2 to be the same as the second end voltage of the third transistor MP3, that is, the drain voltage of the second transistor MP2 and the drain voltage of the third transistor MP3 are the same.
  • the magnitude of the second input current I2 is determined by the output current I3 of the third transistor MP3 and the second current source IQC , wherein the output current I3 of the third transistor MP3 is proportional to the first input current IHBT , and the second current source IQC is a reference current that is not affected by temperature. Therefore, the magnitude of the second input current I2 is proportional to the first input current IHBT.
  • the magnitude of the current I HBT is relevant.
  • the third input terminal 3 of the operational amplifier OPAMP is electrically connected to the power amplifier 10 based on the second end of the second transistor MP2, the fourth input terminal 4 of the operational amplifier OPAMP is electrically connected to the second control port B, and the operational amplifier output terminal out2 of the operational amplifier OPAMP is electrically connected to the third control port C.
  • the first control port A is connected to the third end of the third transistor MP3 in the filter simulation circuit 201
  • the second control port B is connected to the second end of the third transistor MP3 in the filter simulation circuit 201
  • the third control port C is connected to the third end of the fourth transistor MP4 in the filter simulation circuit 201.
  • the second end of the second transistor MP2 and the second end of the third transistor MP3 are electrically connected to the third input terminal 3 and the fourth input terminal 4 of the operational amplifier OPAMP, respectively.
  • the operational amplifier controls the second end voltage of the second transistor MP2 to be the same as the second end voltage of the third transistor MP3, that is, the drain voltage of the second transistor MP2 and the drain voltage of the third transistor MP3 are the same.
  • the second transistor MP2 and the third transistor MP3 both operate in the linear region or the saturation region.
  • the field effect transistor current mirror circuit needs to work in the linear region
  • the bipolar transistor current mirror needs to work in the saturation region. Therefore, when the first transistor, the second transistor, and the third transistor are field effect transistors, the current mirror circuit 203 needs to work in the linear region; when the first transistor, the second transistor, and the third transistor are bipolar transistors, the current mirror circuit 203 needs to work in the saturation region.
  • the following embodiments will no longer describe the specific types and working states of the transistors.
  • the second end of the first transistor MP1 is used to receive the input current of the first current source I LIMIT , the second end of the second transistor MP2 outputs the first input current I HBT according to the input current mirror, and the second end of the third transistor MP3 outputs the output current I 3 of the third transistor MP3 according to the input current mirror, and the first input current I HBT and the output current I 3 of the third transistor MP3 are in a mirror proportional relationship with the current of the first transistor MP1.
  • Figure 6 is a structural schematic diagram of the protection circuit and the amplification circuit provided by the embodiment of the present disclosure.
  • the filter simulation circuit 201 also includes an analog capacitor C1 and a conversion resistor R2; one end of the analog capacitor C1 is electrically connected to one end of the thermal resistance simulation module R1 and the first input terminal 1 respectively, and the other end of the analog capacitor C1 is grounded; one end of the conversion resistor R2 is electrically connected to the other end of the thermal resistance simulation module R1, and the other end of the conversion resistor R2 is grounded.
  • the conversion resistor R2 is used to convert current into voltage.
  • the power amplifier 10 includes at least an amplifying transistor Q.
  • the output current I 3 of the third transistor MP3 is used to simulate the output current of the amplifying transistor Q
  • the current output by the second current source I QC is used to simulate the quiescent current of the amplifying transistor Q.
  • the filter simulation circuit 201 is used to output a filter voltage related to the filter temperature according to the output current, the quiescent current and the thermal resistance simulation module R1.
  • the difference between the output current I 3 of the third transistor MP3 and the output current of the second current source I QC is the second output current I 2
  • the second output current I 2 can be used as the output current of the fourth transistor MP4.
  • the output current of the fourth transistor MP4 is used to simulate the filter current, that is, the current flowing into the filter by the power amplifier.
  • the thermal resistance simulation module R1 is used to simulate the thermal resistance of the filter. After the output current of the fourth transistor MP4 flows through the thermal resistance simulation module R1, a filter voltage V SNS related to the filter temperature is output.
  • the reference voltage circuit 202 at least includes a third current source I PTAT , a fourth current source IR and a voltage divider resistor R3, wherein the positive electrode of the third current source I PTAT is electrically connected to the power supply VDD, the negative electrode of the third current source I PTAT is electrically connected to the positive electrode of the fourth current source IR and the second input terminal 2, respectively, and the negative electrode of the fourth current source IR is grounded; wherein the third current source IPTAT is used to output a current proportional to the ambient temperature, and the fourth current source IR is a constant current source; one end of the voltage divider resistor R3 is electrically connected to the negative electrode of the third current source I PTAT , the positive electrode of the fourth current source IR , and the second input terminal 2, respectively, and the other end is grounded.
  • the reference voltage circuit 202 further includes a fifth transistor MP5 and a sixth transistor MP6.
  • the fifth transistor MP5 and the sixth transistor MP6 form a current mirror.
  • the first end of the body transistor MP6 is electrically connected to the power supply VDD
  • the third end of the fifth transistor MP5 is electrically connected to the third end of the sixth transistor MP6
  • the second end of the fifth transistor MP5 is electrically connected to the second input terminal 2
  • the second end of the sixth transistor MP6 is electrically connected to the third end of the sixth transistor MP6 and the negative electrode of the third current source I PTAT
  • one end of the voltage dividing resistor R3 is electrically connected to the negative electrode of the third current source I PTAT through the fifth transistor MP5 and the sixth transistor MP6.
  • the reference voltage circuit 202 at least includes a fifth transistor MP5, a sixth transistor MP6, a third current source I PTAT , a fourth current source IR and a voltage-dividing resistor R3.
  • the positive electrode of the third current source I PTAT is electrically connected to the power supply VDD
  • the negative electrode of the third current source I PTAT is electrically connected to the positive electrode of the fourth current source IR , the second end and the third end of the sixth transistor MP6, respectively
  • the negative electrode of the fourth current source IR is grounded.
  • the first end of the sixth transistor MP6 is electrically connected to the power supply VDD
  • the third end of the sixth transistor MP6 is electrically connected to the third end of the fifth transistor MP5
  • the first end of the fifth transistor MP5 is electrically connected to the power supply VDD
  • the second end of the fifth transistor MP5 is electrically connected to the second input end and one end of the voltage-dividing resistor R3, respectively, and the other end of the voltage-dividing resistor R3 is grounded.
  • a current proportional to the ambient temperature can be obtained through the third current source I PTAT , and then a current linearly inversely proportional to the ambient temperature is obtained through a constant current source that is not affected by temperature, that is, a fourth current source IR , and is given to the drain of the sixth transistor MP6.
  • a current linearly inversely proportional to the ambient temperature is obtained through a constant current source that is not affected by temperature, that is, a fourth current source IR , and is given to the drain of the sixth transistor MP6.
  • the drain current of the sixth transistor MP6 is the difference between the currents of the third current source I PTAT and the fourth current source IR . Therefore, when the third current source I PTAT obtains a current proportional to the ambient temperature, the drain current of the sixth transistor MP6 is linearly inversely proportional to the ambient temperature.
  • the third end of the fifth transistor MP5 is connected to the third end of the sixth transistor MP6, and the first end of the fifth transistor MP5 and the first end of the sixth transistor MP6 are both electrically connected to the power supply VDD. Therefore, the fifth transistor MP5 and the sixth transistor MP6 constitute a current mirror circuit, and based on the drain current of the sixth transistor MP6, the drain of the fifth transistor MP5 outputs a mirror current corresponding to the drain current of the sixth transistor MP6, and the mirror current is linearly inversely proportional to the ambient temperature.
  • the drain terminal of the fifth transistor MP5 outputs a reference voltage V REF through the voltage divider resistor R3 and the mirror current outputted from the drain terminal of the fifth transistor MP5 .
  • the reference voltage V REF changes with the ambient temperature.
  • the reference voltage V REF may be inversely proportional to the ambient temperature.
  • the temperature of the filter 30 is equal to the ambient temperature plus the heat temperature generated by the operation of the filter.
  • the threshold temperature of filter damage is fixed, the higher the ambient temperature, the lower the threshold of the heat temperature generated by the operation. Therefore, the embodiment of the present disclosure forms a reference voltage V REF that is inversely proportional to the ambient temperature and compares it with the filter voltage V SNS related to the filter temperature.
  • V REF the reference voltage
  • the filter has a critical temperature.
  • the reference voltage V REF is less than the filter voltage V SNS , and the comparison output terminal out1 of the comparator outputs a high level, which is converted by the inverter and given a low level to the gate of the control transistor MN1, and MN1 is cut off.
  • the current of the first transistor MP1 is limited to the current I limit output by the first current source I LIMIT , and the maximum value of the drain current I HBT of the second transistor MP2 after the second transistor MP2 mirrors the first transistor MP1 is limited to M*I limit , thereby limiting the current of the power amplifier, further limiting the output power of the power amplifier, thereby limiting the power of the filter, and preventing the filter temperature from exceeding the critical temperature, so as to achieve temperature adjustment of the filter.
  • the drain current I HBT of the second transistor when the filter temperature is lower than the critical temperature, the drain current I HBT of the second transistor is small, so that the reference voltage V REF is greater than the filter voltage, and the comparison output terminal out1 of the comparator outputs a low level, which is converted by the inverter and given to the gate of the control transistor MN1 as a high level, so that the control transistor MN1 is turned on, so that the Vgate voltage is lower, and the MP2 tube works in the linear region.
  • the current of the control transistor MN1 also flows through the first transistor MP1, the current of the first transistor MP1 increases, and the drain current I HBT of the second transistor MP2 of the mirror MP1 is not limited.
  • the circuit further includes a hysteresis circuit 204, which is electrically connected to the reference voltage circuit 202; the hysteresis circuit 204 at least includes a hysteresis transistor MN2 and a hysteresis resistor R4 connected in parallel.
  • the first end of the hysteresis transistor MN2 is electrically connected to the voltage divider resistor R3 and the hysteresis resistor R4, respectively, the other end of the hysteresis resistor R4 is grounded, the second end of the hysteresis transistor MN2 is grounded, and the third end of the hysteresis transistor MN2 is electrically connected to the comparison output end out1.
  • the hysteresis circuit 204 is used to change the size of the reference voltage V REF according to the filter voltage V SNS and the reference voltage V REF .
  • the comparison output terminal out1 of the comparator COMP outputs a high level
  • the drain current IHBT of the second transistor MP2 is limited, and then the power of the filter is limited.
  • the hysteresis circuit 204 outputs a high level due to the comparison output terminal out1 outputting a high level, so that the hysteresis transistor MN2 is turned on, and the reference voltage V REF is further reduced through the hysteresis transistor MN2 and the hysteresis resistor R4.
  • the filter temperature is less than the critical temperature of the filter.
  • the reference voltage V REF is greater than the filter voltage V SNS , the comparison output terminal out1 outputs a low level, and the hysteresis transistor MN2 is turned off. In this way, the repeated conversion of the comparator output logic level due to thermal oscillation can be prevented, and the reliability of components is improved.
  • the embodiment of the present disclosure further provides an amplifier circuit, which at least includes a power amplifier 10, a protection circuit 20 electrically connected to the power amplifier 10, and the power amplifier 10 electrically connected to a filter 30.
  • the power amplifier 10 at least includes a bias circuit 101 and an amplifier transistor Q.
  • One end of the bias circuit 101 is electrically connected to the second end of the second transistor MP2 in the current mirror circuit 203, that is, electrically connected to the drain of the second transistor MP2 in the current mirror circuit 203, and the other end of the bias circuit 101 is electrically connected to the third end (that is, the base) of the amplifier transistor Q; the emitter of the amplifier transistor Q is grounded, and the collector of the amplifier transistor Q is electrically connected to the filter 30.
  • the first input current I HBT is used to feed the bias circuit 101 ; the power amplifier 10 is used to amplify the first input current I HBT and input the amplified first input current to the filter 30 .
  • a current that is linearly inversely proportional to the ambient temperature is obtained through the third current source I PTAT and the fourth current source IR , the current is converted through a current mirror formed by the fifth transistor MP5 and the sixth transistor MP6, and then the current is converted into a voltage through the voltage divider resistor R3 and the hysteresis resistor R4, thereby obtaining a reference voltage V REF for comparison with the filter thermal temperature, the reference voltage V REF changes with temperature, the reference voltage V REF is compared with the filter voltage V SNS through the comparator COMP, and the current I HBT of the power amplifier 10 is adjusted by controlling the transistor MN1.
  • the drain current I HBT of the second transistor MP2 is small, so that the filter voltage V SNS is less than the reference voltage V REF , and therefore the gate voltage of the control transistor MN1 is high.
  • the Vgate voltage is low, and the MP2 operates in the linear region.
  • the maximum value of the drain current I HBT of the second transistor MP2 after the second transistor MP2 mirrors the first transistor MP1 is limited to M*I limit , thereby limiting the current of the power amplifier, further limiting the output power of the power amplifier, thereby limiting the power of the filter, and preventing the filter temperature from exceeding the critical temperature, so as to achieve the temperature adjustment of the filter.
  • Figure 7 is a schematic diagram of the relationship between the critical power of the filter provided in the embodiment of the present disclosure and the ambient temperature
  • Figure 8 is a schematic diagram of the relationship between the critical temperature of the filter provided in the embodiment of the present disclosure and the ambient temperature.
  • the relationship between the critical power (PTH) of the filter and the ambient temperature (Ta) is shown in Figure 7
  • the relationship between the critical temperature (Tf0) of the filter and the ambient temperature (Ta) is shown in Figure 8.
  • the critical power PTH of the filter in the related art does not change with the change of the ambient temperature Ta, which will cause the critical temperature Tf0 of the filter to increase linearly with the increase of the ambient temperature Ta, causing the filter to fail due to high temperature; and after the protection circuit is optimized by the embodiment of the present disclosure, the critical power PTH of the filter decreases linearly with the change of the ambient temperature Ta, so that the critical temperature Tf0 of the filter does not change with the increase of the ambient temperature Ta, achieving the optimization. Effect.
  • the disclosed embodiment not only automatically adjusts the maximum power output of the power amplifier according to the ambient temperature and realizes automatic tracking of the filter temperature; it also links power and temperature together by simulating the thermal resistance of the filter, and utilizes the linear relationship between power and current to sample the branch current of the power amplifier to realize temperature monitoring of the filter, thereby achieving more accurate protection of the filter.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)

Abstract

本公开涉及一种保护电路及放大电路，其中，比较器至少包括第一输入端、第二输入端和比较输出端；滤波器模拟电路与第一输入端电连接，滤波器模拟电路用于模拟滤波器的电流，并输出与滤波器温度相关的滤波器电压；基准电压电路与第二输入端电连接，基准电压电路用于输出与环境温度相关的基准电压；电流镜电路分别与比较输出端、功率放大器和滤波器模拟电路电连接，电流镜电路用于为功率放大器提供第一输入电流，滤波器模拟电路用于根据第一输入电流，获取用于模拟滤波器电流的第二输入电流；比较器用于根据滤波器电压和基准电压，控制电流镜电路改变第一输入电流和第二输入电流的大小，以控制滤波器的温度。

Description

一种保护电路及放大电路
相关申请的交叉引用
本公开基于申请号为202310682633.4、申请日为2023年06月09日、申请名称为“一种保护电路及放大电路”的中国专利申请提出，并要求该中国专利申请的优先权，该中国专利申请的全部内容在此引入本公开作为参考。
技术领域
本公开涉及但不限于模拟集成电路技术领域，尤其涉及一种保护电路及放大电路。
背景技术
无线通信协议从3G(Generation)到4G、5G发展过程中，射频信号的传输频率越来越高，由于频率的提高，功率器件的高功率增加了滤波器因发热而烧毁的风险。为了保证射频前端模组的可靠性，需要持续监控滤波器的功率，保护其在极端条件下不会因过度发热被烧毁。
目前，现有技术往往是直接检测功率器件的温度，如采用热敏电阻或三极管等对温度敏感器件对温度采样，并将温度信号转化为便于处理的电信号，从而实现对温度变化的快速响应和对功率器件的保护。但在射频前端电路中，由于制作工艺的限制，滤波器中无法集成三极管，因此无法直接检测滤波器的温度，而热敏电阻灵敏度较低，检测精度难以保证。且传统的功率放大器模块中，由于三极管的集电极直接与电源连接，使得传统的功率放大器模块无法集成保护电路，因此，传统的功率放大器模块无法保护滤波器。
发明内容
基于相关技术中的问题，本公开实施例提供一种保护电路及放大电路。
本公开实施例的技术方案是这样实现的：
本公开实施例提供一种保护电路，所述保护电路用于与功率放大器电连接，所述功率放大器与滤波器电连接；所述保护电路至少包括滤波器模拟电路、基准电压电路、比较器和电流镜电路；所述比较器至少包括第一输入端、第二输入端和比较输出端；
所述滤波器模拟电路与所述第一输入端电连接，所述滤波器模拟电路用于模拟所述滤波器的电流，并输出与所述滤波器温度相关的滤波器电压；
所述基准电压电路与所述第二输入端电连接，所述基准电压电路用于输出与环境温度相关的基准电压；
所述电流镜电路分别与所述比较输出端、所述功率放大器和所述滤波器模拟电路电连接，所述电流镜电路用于为所述功率放大器提供第一输入电流；所述滤波器模拟电路用于根据所述第一输入电流，获取用于模拟所述滤波器电流的第二输入电流；
所述比较器用于根据所述滤波器电压和所述基准电压，控制所述电流镜电路改变所述第一输入电流和所述第二输入电流的大小，以控制所述滤波器的温度。
本公开实施例提供一种放大电路，所述放大电路与上述的保护电路连接，所述放大电路至少包括所述功率放大器；所述功率放大器至少包括偏置电路和放大晶体管；
所述偏置电路的一端与所述电流镜电路中第二晶体管的第二端电连接，所述偏置电路的另一端与放大晶体管的第三端电连接；
所述放大晶体管的发射极接地，所述放大晶体管的集电极与所述滤波器电连接；
所述第一输入电流用于为所述偏置电路馈电；
所述功率放大器用于对所述第一输入电流进行放大，并将放大后的第一输入电流输入至所述滤波器。
本公开实施例提供一种射频芯片，所述射频芯片包括上述保护电路。
本公开实施例提供一种电子设备，所述电子设备包括上述保护电路或射频芯片。
本公开实施例提供的保护电路及放大电路，首先，通过对比与滤波器温度相关的滤波器电压和与环境温度相关的基准电压，改变流经滤波器的电流大小，调整功率放大器的功率输出，如此，本公开实施例根据功率和电流的线性关系，将电流和滤波器温度联系在一起，实现了对滤波器的温度监控，进而通过保护电路实现对滤波器的保护；其次，本公开直接对电信号进行采样，并利用滤波器的电阻间接监控滤波器温度，从而实现对功率模块进行保护，无需在滤波器中集成温度检测元件，既降低了成本，也减小了滤波器的尺寸。
应当理解的是，以上的一般描述和后文的细节描述仅是示例性和解释性的，而非限制本公开。根据下面参考附图对示例性实施例的详细说明，本公开的其它特征及方面将变得清楚。
附图说明
为了更清楚地说明本公开实施例的技术方案，下面将对本公开实施例中所需要使用的附图进行说明。
此处的附图被并入说明书中并构成本说明书的一部分，这些附图示出了符合本公开的实施例，并与说明书一起用于说明本公开的技术方案。
图1是相关技术中的功率放大器模块的结构示意图；
图2是本公开实施例提供的保护电路及放大电路的一种结构示意图；
图3是本公开实施例提供的保护电路及放大电路的另一种结构示意图；
图4是本公开实施例提供的电流镜电路的结构示意图；
图5是本公开实施例提供的滤波器模拟电路的结构示意图；
图6是本公开实施例提供的保护电路及放大电路的结构示意图；
图7是本公开实施例提供的滤波器的临界功率与环境温度的关系示意图；
图8是本公开实施例提供的滤波器的临界温度与环境温度的关系示意图。
具体实施方式
为了使本公开的目的、技术方案和优点更加清楚，下面将结合附图对本公开作进一步地详细描述，所描述的实施例不应视为对本公开的限制，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其它实施例，都属于本公开保护的范围。
在以下的描述中，涉及到“一些实施例”，其描述了所有可能实施例的子集，但是可以理解，“一些实施例”可以是所有可能实施例的相同子集或不同子集，并且可以在 不冲突的情况下相互结合。除非另有定义，本公开实施例所使用的所有的技术和科学术语与属于本公开实施例的技术领域的技术人员通常理解的含义相同。本公开实施例所使用的术语只是为了描述本公开实施例的目的，不是旨在限制本公开。
另外，为了更好地说明本公开，在下文的具体实施方式中给出了众多的具体细节。本领域技术人员应当理解，没有某些具体细节，本公开同样可以实施。在一些实例中，对于本领域技术人员熟知的方法、手段、元件和电路未作详细描述，以便于凸显本公开的主旨。
图1是相关技术中的功率放大器模块的结构示意图，如图1所示，相关技术中的功率放大器模块至少包括偏置电路101、匹配电路102和放大晶体管Q4，其中，偏置电路101中三极管Q3的集电极直接与电源VDD连接，使得相关技术中的功率放大器模块无法集成保护电路，因此无法保护滤波器。
基于相关技术存在的问题，本公开实施例提供一种保护电路，图2是本公开实施例提供的保护电路及放大电路的结构示意图，保护电路20与功率放大器10电连接，功率放大器10与滤波器30电连接。保护电路20至少包括滤波器模拟电路201、基准电压电路202、比较器COMP和电流镜电路203；比较器至少包括第一输入端1、第二输入端2和比较输出端out1。
在一些实施例中，滤波器模拟电路201与第一输入端1电连接，滤波器模拟电路201用于模拟滤波器30的电流，并输出与滤波器30温度相关的滤波器电压VSNS；基准电压电路202与第二输入端2电连接，基准电压电路202用于输出与环境温度相关的基准电压VREF；电流镜电路203分别与比较输出端out1、功率放大器10和滤波器模拟电路201电连接，电流镜电路203用于为功率放大器10提供第一输入电流IHBT，滤波器模拟电路201用于根据第一输入电流IHBT，获取用于模拟滤波器电流的第二输入电流I2；比较器COMP用于根据滤波器电压VSNS和基准电压VREF，控制电流镜电路203改变第一输入电流IHBT的大小，从而调节功率放大器的功率，以控制滤波器30的温度，其中，第二输入电流I2跟随IHBT变化。
在一些实施例中，滤波器模拟电路201具有临界温度；当滤波器模拟电路201的温度大于或等于临界温度时，电流镜电路用于限制第一输入电流IHBT和第二输入电流I2的电流值小于预设电流值，以限制功率放大器10和滤波器30的功率，以控制滤波器30的温度。
在一些实施例中，当滤波器模拟电路201的温度大于或等于临界温度时，滤波器30电压大于基准电压。
本公开实施例通过对比与滤波器温度相关的滤波器电压和与环境温度相关的基准电压，改变流经滤波器的电流大小，调整功率放大器的功率输出，本公开根据功率和电流的线性关系，将电流和滤波器温度联系在一起，实现了对滤波器的温度监控，进而实现对滤波器的保护；且本公开直接对电信号进行采样，并利用滤波器的电阻间接监控滤波器温度，从而实现对功率模块进行保护，无需在滤波器中集成温度检测元件，既降低了成本，也减小了滤波器的尺寸。
接下来请参照图3，图3是本公开实施例提供的保护电路及放大电路的结构示意图，如图3所示，电流镜电路203至少包括控制晶体管MN1、第一电流源ILIMIT和电流镜单元。
在一些实施例中，电路还包括反相器inverter，反相器inverter分别与比较输出端out1和电流镜电路203电连接。
其中，控制晶体管MN1的第一端与电流镜单元电连接，控制晶体管MN1的第二端 接地，控制晶体管MN1的第三端通过反相器与比较器COMP的输出端out1电连接，控制晶体管MN1用于调节第一输入电流IHBT的大小。第一电流源ILIMIT的正极分别与电流镜单元、控制晶体管MN1的第一端电连接，第一电流源ILIMIT的负极接地，第一电流源ILIMIT用于配合控制晶体管MN1调节第一输入电流IHBT和第二输入电流I2的大小。
在一些实施例中，图4是本公开实施例提供的电流镜电路的结构示意图，如图4所示，电流镜单元至少包括第一晶体管MP1、第二晶体管MP2。
在本公开实施例中，晶体管的第一端为晶体管的源极，晶体管的第二端为晶体管的漏极，晶体管的第三端为晶体管的栅极。其他实施例中，晶体管也可以为三极管等，此处不做限制。
在电流镜电路203的电流镜单元中，第一晶体管MP1和第二晶体管MP2的第一端与电源VDD电连接；第一晶体管MP1的第二端与控制晶体管MN1的第一端电连接，控制晶体管MN1的第二端接地，控制晶体管MN1的第三端通过反相器inverter与比较器COMP的比较输出端out1电连接；第一晶体管MP1的第三端分别与第一控制端口A、第二晶体管MP2的第三端、第一电流源ILIMIT的正极电连接；第二晶体管MP2的第二端和功率放大器10电连接，用于输出第一输入电流IHBT，其中，第一晶体管MP1、第二晶体管MP2形成第一电流镜电路，以使第一输入电流IHBT与第一晶体管MP1的输出电流成比例，从而通过调节第一晶体管MP1的输出电流对第一输入电流IHBT、第二输入电流I2进行调节。
具体地，当滤波器模拟电路201的温度大于或等于临界温度时，控制晶体管MN1关闭，第一晶体管MP1的电流被限制为第一电流源ILIMIT的电流，进而限制第一输入电流IHBT和第二输入电流I2的电流值。当滤波器模拟电路201的温度小于临界温度时，控制晶体管MN1开启，第一晶体管MP1的电流与为控制晶体管MN1的电流与ILIMIT之和。
接下来请继续参照图3，如图3所示，滤波器模拟电路201包括电流模拟模块及热阻模拟模块R1，其中，电流模拟模块与热阻模拟模块R1连接，热阻模拟模块R1用于模拟滤波器30的热阻。
一些实施例中，电流模拟模块包括第三晶体管MP3、第二电流源IQC。第三晶体管MP3的第一端与电源VDD电连接，第三晶体管MP3的第二端与热阻模拟模块电连接，第三晶体管MP3的第三端与电流镜电路的第一控制端口A电连接，第二输入电流I2的大小通过第三晶体管MP3的输出电流I3与第二电流源IQC确定，其中，第三晶体管MP3的输出电流I3与电流镜电路的第一输入电流IHBT成比例。
一些实施例中，第三晶体管MP3的第一端与电源VDD电连接，第三晶体管MP3的第二端与热阻模拟模块R1电连接，第三晶体管MP3的第三端与第一控制端口A电连接。第一晶体管MP1与第三晶体管MP3形成第二电流镜电路，以控制第二晶体管MP2的电流IHBT与第三晶体管MP3的电流I3成比例。
一些实施例中，电流模拟模块还包括运算放大器OPMAP、第四晶体管MP4，如图5所示，图5是本公开实施例提供的滤波器模拟电路的结构示意图。运算放大器OPMAP包括第三输入端3、第四输入端4和运放输出端out2；电流镜电路203中的第二晶体管MP2的第二端和第三晶体管MP3的第二端分别与运算放大器OPAMP的第三输入端3和第四输入端4电连接，运算放大器控制第二晶体管MP2的第二端电压与第三晶体管MP3的第二端电压相同，即第二晶体管MP2与第三晶体管MP3的漏极电压相同。
在一些实施例中，第二输入电流I2的大小通过第三晶体管MP3的输出电流I3与第二电流源IQC确定，其中，第三晶体管MP3的输出电流I3与第一输入电流IHBT成比例，第二电流源IQC为不受温度影响的基准电流，因此，第二输入电流I2的大小与第一输入 电流IHBT的大小相关。
在一些实施例中，运算放大器OPAMP的第三输入端3基于第二晶体管MP2的第二端与功率放大器10电连接，运算放大器OPAMP的第四输入端4与第二控制端口B电连接，运算放大器OPAMP的运放输出端out2与第三控制端口C电连接。
在本公开实施例中，第一控制端口A与滤波器模拟电路201中的第三晶体管MP3的第三端连接，第二控制端口B与滤波器模拟电路201中的第三晶体管MP3的第二端连接，第三控制端口C与滤波器模拟电路201中的第四晶体管MP4的第三端连接。
这里，第二晶体管MP2的第二端和第三晶体管MP3的第二端分别与运算放大器OPAMP的第三输入端3和第四输入端4电连接，运算放大器控制第二晶体管MP2的第二端电压与第三晶体管MP3的第二端电压相同，即第二晶体管MP2与第三晶体管MP3的漏极电压相同，基于第二晶体管MP2与第三晶体管MP3的栅极电压Vgate，使第二晶体管MP2和第三晶体管MP3均工作于线性区或饱和区。
这里，为了从功率放大器的HBT端口看向保护电路为低阻，场效应晶体管电流镜电路需要工作在线性区，双极晶体管电流镜需要工作在饱和区。因此，当第一晶体管、第二晶体管和第三晶体管为场效应晶体管时，电流镜电路203需要工作在线性区；当第一晶体管、第二晶体管和第三晶体管为双极晶体管时，电流镜电路203需要工作在饱和区。下述实施例不再对晶体管的具体类型和工作状态进行描述。
在一些实施例中，第一晶体管MP1的第二端用于接收第一电流源ILIMIT的输入电流，第二晶体管MP2的第二端根据输入电流镜像输出第一输入电流IHBT，第三晶体管MP3的第二端根据输入电流镜像输出第三晶体管MP3的输出电流I3，第一输入电流IHBT和第三晶体管MP3的输出电流I3与第一晶体管MP1的电流成镜像比例关系。
在一些实施例中，图6是本公开实施例提供的保护电路及放大电路的结构示意图，如图6所示，滤波器模拟电路201还包括模拟电容C1和转换电阻R2；模拟电容C1的一端分别与热阻模拟模块R1的一端和第一输入端1电连接，模拟电容C1的另一端接地；转换电阻R2的一端与热阻模拟模块R1的另一端电连接，转换电阻R2的另一端接地，转换电阻R2用于将电流转换为电压。
在一些实施例，功率放大器10至少包括放大晶体管Q，如图6所示，第三晶体管MP3的输出电流I3用于模拟放大晶体管Q的输出电流，第二电流源IQC输出的电流用于模拟放大晶体管Q的静态电流。滤波器模拟电路201用于根据输出电流、静态电流和热阻模拟模块R1，输出与滤波器温度相关的滤波器电压。这里，第三晶体管MP3的输出电流I3与第二电流源IQC的输出电流之间的差值为第二输出电流I2，第二输出电流I2可以作为第四晶体管MP4的输出电流，第四晶体管MP4的输出电流用于模拟滤波器电流，即功率放大器流入滤波器的电流。
在一些实施例中，热阻模拟模块R1用于模拟滤波器的热阻，第四晶体管MP4的输出电流流过热阻模拟模块R1后，输出与滤波器温度相关的滤波器电压VSNS。
在一些实施例中，如图6所示，基准电压电路202至少包括第三电流源IPTAT、第四电流源IR和分压电阻R3，其中，第三电流源IPTAT的正极与电源VDD电连接，第三电流源IPTAT的负极分别与第四电流源IR的正极、第二输入端2电连接，第四电流源IR的负极接地；其中，第三电流源IPTAT用于输出与环境温度成比例的电流，第四电流源IR为恒流源；分压电阻R3的一端分别与第三电流源IPTAT的负极、第四电流源IR的正极、第二输入端2电连接，另一端接地。
如图6所示，基准电压电路202还包括第五晶体管MP5、第六晶体管MP6。其中，第五晶体管MP5与第六晶体管MP6形成电流镜，第五晶体管MP5的第一端、第六晶 体管MP6的第一端均与电源VDD电连接，第五晶体管MP5的第三端与第六晶体管MP6的第三端电连接，第五晶体管MP5的第二端与第二输入端2电连接，第六晶体管MP6的第二端与第六晶体管MP6的第三端、第三电流源IPTAT的负极电连接；分压电阻R3的一端通过第五晶体管MP5、第六晶体管MP6与第三电流源IPTAT的负极电连接。
在一些实施例中，如图6所示，基准电压电路202至少包括第五晶体管MP5、第六晶体管MP6、第三电流源IPTAT、第四电流源IR和分压电阻R3。第三电流源IPTAT的正极与电源VDD电连接，第三电流源IPTAT的负极分别与第四电流源IR的正极、第六晶体管MP6的第二端和第三端电连接，第四电流源IR的负极接地。第六晶体管MP6的第一端与电源VDD电连接，第六晶体管MP6的第三端与第五晶体管MP5的第三端电连接，第五晶体管MP5的第一端与电源VDD电连接，第五晶体管MP5的第二端分别与第二输入端和分压电阻R3的一端电连接，分压电阻R3的另一端接地。
在一些实施例中，通过第三电流源IPTAT可以获取与环境温度成正比的电流，再通过不受温度影响的恒流源，即第四电流源IR，得到与环境温度成线性反比的电流给到第六晶体管MP6的漏极。这里，由于第三电流源IPTAT的负极与第四电流源IR的正极连接，而第四电流源IR为不受温度影响的恒流源，因此，第六晶体管MP6的漏极电流为第三电流源IPTAT与第四电流源IR的电流之差，因此，在第三电流源IPTAT获取与环境温度成正比的电流的情况下，第六晶体管MP6的漏极电流与环境温度成线性反比。
在一些实施例中，第五晶体管MP5的第三端和第六晶体管MP6的第三端连接，第五晶体管MP5的第一端和第六晶体管MP6的第一端均与电源VDD电连接，因此，第五晶体管MP5和第六晶体管MP6构成电流镜电路，基于第六晶体管MP6的漏极电流，第五晶体管MP5的漏极输出第六晶体管MP6的漏极电流对应的镜像电流，该镜像电流与环境温度成线性反比。
这里，通过分压电阻R3和第五晶体管MP5的漏极端输出的镜像电流，使得第五晶体管MP5的漏极端输出基准电压VREF，基准电压VREF随环境温度发生变化，这里可以是基准电压VREF与环境温度成反比。
在本公开实施例中，滤波器30的温度等于环境温度加上由于滤波器工作产生的热温度，当滤波器损坏的阈值温度固定时，环境温度越高时，由于工作产生的热温度的阈值就越低，因此本公开实施例通过形成一个与环境温度成反比的基准电压VREF与滤波器温度相关的滤波器电压VSNS进行比较，当环境温度越高，滤波器热温度的阈值越低，而此时基准电压VREF就越低。
在一些实施例中，滤波器具有临界温度，当滤波器温度达到临界温度并继续升高时，基准电压VREF小于滤波器电压VSNS，比较器的比较输出端out1输出高电平，经反相器inverter转换后，给到控制晶体管MN1的栅极低电平，MN1截止，此时，第一晶体管MP1的电流被限定在第一电流源ILIMIT输出的电流Ilimit，则第二晶体管MP2镜像第一晶体管MP1后的第二晶体管MP2的漏极电流IHBT的最大值被限定在M*Ilimit，从而限制了功率放大器的电流，进一步限制了功率放大器的输出功率，从而限定了滤波器的功率，阻止滤波器温度超过临界温度，以实现滤波器的温度进行调节。
在一些实施例中，当滤波器温度小于临界温度时，第二晶体管的漏极电流IHBT较小，从而基准电压VREF大于滤波器电压，比较器的比较输出端out1输出低电平，经反相器inverter转换后，给到控制晶体管MN1的栅极为高电平，使得控制晶体管MN1导通，使得Vgate电压较低，MP2管工作在线性区，此时，控制晶体管MN1的电流也流过第一晶体管MP1，第一晶体管MP1的电流增加，镜像MP1的第二晶体管MP2的漏极电流IHBT不受限。
在一些实施例中，如图5所示，电路还包括迟滞电路204，迟滞电路204与基准电压电路202电连接；迟滞电路204至少包括并联的迟滞晶体管MN2和迟滞电阻R4。其中，迟滞晶体管MN2的第一端分别与分压电阻R3和迟滞电阻R4电连接，迟滞电阻R4的另一端接地，迟滞晶体管MN2的第二端接地，迟滞晶体管MN2的第三端与比较输出端out1电连接。
这里，迟滞电路204用于根据滤波器电压VSNS和基准电压VREF，改变基准电压VREF的大小。这里，比较器COMP的比较输出端out1输出高电平后，第二晶体管MP2的漏极电流IHBT被限定，进而滤波器的功率被限定，此时，迟滞电路204由于比较输出端out1输出高电平，使得迟滞晶体管MN2导通，通过迟滞晶体管MN2和迟滞电阻R4使得基准电压VREF进一步降低，当滤波器的热温度降低到滤波器的热温度阈值后，滤波器温度小于滤波器的临界温度，此时基准电压VREF大于滤波器电压VSNS，比较输出端out1输出低电平，迟滞晶体管MN2截止，如此，可以防止因热振荡导致比较器输出逻辑电平的反复变换，提高了元器件的可靠性。
本公开实施例再提供一种放大电路，放大电路至少包括功率放大器10，保护电路20与功率放大器10电连接，功率放大器10与滤波器30电连接。其中，功率放大器10至少包括偏置电路101和放大晶体管Q。偏置电路101的一端与电流镜电路203中第二晶体管MP2的第二端电连接，即与电流镜电路203中第二晶体管MP2的漏极电连接，偏置电路101的另一端与放大晶体管Q的第三端(即基极)电连接；放大晶体管Q的发射极接地，放大晶体管Q的集电极与滤波器30电连接。
在一些实施例中，第一输入电流IHBT用于为偏置电路101馈电；功率放大器10用于对第一输入电流IHBT进行放大，并将放大后的第一输入电流输入至滤波器30。
在本公开实施例中，基准电压电路202中，通过第三电流源IPTAT和第四电流源IR获取与环境温度成线性反比的电流，将电流通过第五晶体管MP5和第六晶体管MP6形成的电流镜进行转换，再通过分压电阻R3和迟滞电阻R4将电流转换为电压，从而得到用于与滤波器热温度进行比较的基准电压VREF，基准电压VREF随温度变化，将基准电压VREF与滤波器电压VSNS通过比较器COMP进行比较，从而通过控制晶体管MN1对功率放大器10的电流IHBT进行调节。
在一些实施例中，当滤波器温度小于临界温度时，第二晶体管MP2漏极电流IHBT较小，从而滤波器电压VSNS小于基准电压VREF，因此控制晶体管MN1管的栅端电压为高电平，此时，Vgate电压较低，MP2管工作在线性区。当滤波器温度一旦达到临界温度并继续升高时，控制晶体管MN1管的栅端电压转换为低电平，MN1截止，第一晶体管MP1的电流被限定在第一电流源ILIMIT输出的电流Ilimit，则第二晶体管MP2镜像第一晶体管MP1后的第二晶体管MP2的漏极电流IHBT的最大值被限定在M*Ilimit，从而限制了功率放大器的电流，进一步限制了功率放大器的输出功率，从而限定了滤波器的功率，阻止滤波器温度超过临界温度，以实现滤波器的温度进行调节。
接下来请参照图7和图8，图7是本公开实施例提供的滤波器的临界功率与环境温度的关系示意图，图8是本公开实施例提供的滤波器的临界温度与环境温度的关系示意图。滤波器临界功率(PTH)与环境温度(Ta)之间的关系如图7所示，滤波器临界温度(Tf0)与环境温度(Ta)之间的关系如图8所示，其中，在本公开提出的保护电路之前，相关技术中的滤波器临界功率PTH不随环境温度Ta的变化而变化，这会导致滤波器的临界温度Tf0随环境温度Ta的增加而线性增大，会造成滤波器因高温失效；而通过本公开实施例提供的保护电路优化后，滤波器临界功率PTH随环境温度Ta的变化而线性减小，使得滤波器的临界温度Tf0不随环境温度Ta的增加而变化，达到了优化 效果。
本公开实施例不仅根据环境温度自动调整了功率放大器最大功率输出，实现了对滤波器温度的自动追踪；还通过模拟滤波器的热阻，将功率和温度联系在一起，并利用功率和电流的线性关系，对功率放大器支路电流采样，实现对滤波器的温度监控，从而实现对滤波器更精准的保护。
以上所述，仅为本公开的实施例而已，并非用于限定本公开的保护范围。凡在本公开的精神和范围之内所作的任何修改、等同替换和改进等，均包含在本公开的保护范围之内。
应理解，说明书通篇中提到的“一个实施例”或“一实施例”意味着与实施例有关的特定特征、结构或特性包括在本公开的至少一个实施例中。因此，在整个说明书各处出现的“在一个实施例中”或“在一实施例中”未必一定指相同的实施例。此外，这些特定的特征、结构或特性可以任意适合的方式结合在一个或多个实施例中。应理解，在本公开的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本公开实施例的实施过程构成任何限定。上述本公开实施例序号仅仅为了描述，不代表实施例的优劣。
需要说明的是，在本文中，术语“包括”、“包含”或者其任何其他变体意在涵盖非排他性的包含，从而使得包括一系列要素的过程、方法或者装置不仅包括那些要素，而且还包括没有明确列出的其他要素，或者是还包括为这种过程、方法或者装置所固有的要素。在没有更多限制的情况下，由语句“包括一个……”限定的要素，并不排除在包括该要素的过程、方法、物品或者装置中还存在另外的相同要素。在本公开所提供的几个实施例中，应该理解到，所揭露的设备和方法，可以通过其它的方式实现。以上所描述的设备实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，如：多个单元或组件可以结合，或可以集成到另一个系统，或一些特征可以忽略，或不执行。
以上所述，仅为本公开的实施方式，但本公开的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本公开揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本公开的保护范围之内。因此，本公开的保护范围应以所述权利要求的保护范围为准。
以上已经描述了本公开的各实施例，上述说明是示例性的，并非穷尽性的，并且也不限于所披露的各实施例。在不偏离所说明的各实施例的范围和精神的情况下，对于本技术领域的普通技术人员来说许多修改和变更都是显而易见的。本文中所用术语的选择，旨在最好地解释各实施例的原理、实际应用或对市场中的技术的改进，或者使本技术领域的其它普通技术人员能理解本文披露的各实施例。

Claims (13)

  1. 一种保护电路，所述保护电路用于与功率放大器电连接，所述功率放大器与滤波器电连接；所述保护电路至少包括滤波器模拟电路、基准电压电路、比较器和电流镜电路；所述比较器至少包括第一输入端、第二输入端和比较输出端；
    所述滤波器模拟电路与所述第一输入端电连接，所述滤波器模拟电路用于模拟所述滤波器的电流，并输出与所述滤波器温度相关的滤波器电压；
    所述基准电压电路与所述第二输入端电连接，所述基准电压电路用于输出与环境温度相关的基准电压；
    所述电流镜电路分别与所述比较输出端、所述功率放大器和所述滤波器模拟电路电连接，所述电流镜电路用于为所述功率放大器提供第一输入电流；所述滤波器模拟电路用于根据所述第一输入电流，获取用于模拟所述滤波器电流的第二输入电流；
    所述比较器用于根据所述滤波器电压和所述基准电压，控制所述电流镜电路改变所述第一输入电流和所述第二输入电流的大小，以控制所述滤波器的温度。
  2. 根据权利要求1所述的电路，所述电流镜电路包括控制晶体管、第一电流源和电流镜单元；
    所述控制晶体管的第一端与所述电流镜单元电连接，所述控制晶体管的第二端接地，所述控制晶体管的第三端与所述比较器的输出端电连接，所述控制晶体管用于调节所述第一输入电流和所述第二输入电流的大小；
    所述第一电流源的正极分别与所述电流镜单元、所述控制晶体管的第一端电连接，所述第一电流源的负极接地，所述第一电流源用于配合所述控制晶体管调节所述第一输入电流和所述第二输入电流的大小。
  3. 根据权利要求2所述的电路，所述滤波器模拟电路具有临界温度；
    当所述滤波器模拟电路的温度大于或等于所述临界温度时，所述控制晶体管限制所述第一输入电流、所述第二输入电流小于预设电流值，以限制所述功率放大器和所述滤波器的功率，以控制所述滤波器的温度。
  4. 根据权利要求3所述的电路，当所述滤波器模拟电路的温度大于或等于所述临界温度时，所述滤波器电压大于所述基准电压。
  5. 根据权利要求2所述的电路，所述电路还包括反相器，所述反相器分别与所述比较输出端和所述控制晶体管的第三端电连接。
  6. 根据权利要求2所述的电路，所述电流镜单元至少包括第一晶体管和第二晶体管；
    所述第一晶体管和所述第二晶体管的第一端与电源电连接，所述第一晶体管的第二端与所述控制晶体管的第一端电连接，所述第一晶体管的第三端分别与第一控制端口和所述第二晶体管的第三端电连接；
    所述第二晶体管的第二端用于与所述功率放大器电连接，并输出所述第一输入电流。
  7. 根据权利要求6所述的电路，所述滤波器模拟电路包括电流模拟模块及热阻模拟模块；
    所述电流模拟模块与所述热阻模拟模块连接，所述热阻模拟模块用于模拟所述滤波器的热阻。
  8. 根据权利要求7所述的电路，所述电流模拟模块至少包括第三晶体管和第二电流源；
    所述第三晶体管的第一端与电源电连接，所述第三晶体管的第二端与所述热阻模拟模块电连接，所述第三晶体管的第三端与所述电流镜电路的第一控制端口电连接；
    所述第二输入电流基于所述第三晶体管的输出电流与所述第二电流源获取，所述第三晶体管的输出电流与所述第一输入电流成比例。
  9. 根据权利要求8所述的电路，所述电流模拟模块还包括运算放大器和第四晶体管；所述运算放大器包括第三输入端、第四输入端和运放输出端；
    所述第三输入端分别与所述第二晶体管的第二端和所述功率放大器电连接，所述运算放大器的第四输入端与第二控制端口电连接，所述运算放大器的运放输出端与第三控制端口电连接；
    所述第四晶体管的第一端分别与第三晶体管的第二端和第二电流源的正极电连接，所述第四晶体管的第二端与所述热阻模拟模块的一端电连接，所述第四晶体管的第三端与所述电流镜电路的第三控制端口电连接，所述热阻模拟模块的另一端与所述第一输入端电连接。
  10. 根据权利要求1所述的电路，所述基准电压电路至少包括第三电流源、第四电流源和分压电阻；
    所述第三电流源的正极与电源电连接，所述第三电流源的负极分别与第四电流源的正极、所述第二输入端电连接，所述第四电流源的负极接地；其中，所述第三电流源用于输出与环境温度成比例的电流，所述第四电流源为恒流源；
    所述分压电阻的一端分别与所述第三电流源的负极、所述第四电流源的正极、所述第二输入端电连接，另一端接地。
  11. 根据权利要求10所述的电路，所述基准电压电路还包括第五晶体管、第六晶体管；
    所述第五晶体管与所述第六晶体管形成电流镜，所述第五晶体管的第一端、所述第六晶体管的第一端均与电源电连接，所述第五晶体管的第三端与所述第六晶体管的第三端电连接，所述第五晶体管的第二端与所述第二输入端电连接，所述第六晶体管的第二端与所述第六晶体管的第三端、所述第三电流源的负极电连接；
    所述分压电阻的一端通过所述第五晶体管、所述第六晶体管与所述第三电流源的负极电连接。
  12. 根据权利要求1至11任一项所述的电路，所述电路还包括迟滞电路，所述迟滞电路与所述基准电压电路电连接；所述迟滞电路至少包括并联的迟滞晶体管和迟滞电阻；
    所述迟滞晶体管的第一端分别与分压电阻和迟滞电阻电连接，所述迟滞电阻的另一端接地，所述迟滞晶体管的第二端接地，所述迟滞晶体管的第三端与所述比较输出端电连接；
    所述迟滞电路用于根据所述滤波器电压和所述基准电压，改变所述基准电压的大小。
  13. 一种放大电路，所述放大电路与权利要求1至12任一项所述的保护电路连接，所述放大电路至少包括功率放大器；所述功率放大器至少包括偏置电路和放大晶体管；
    所述偏置电路的一端与保护电路的电流镜电路中第二晶体管的第二端电连接，所述偏置电路的另一端与放大晶体管的第三端电连接；
    所述放大晶体管的发射极接地，所述放大晶体管的集电极与滤波器电连接；
    第一输入电流用于为所述偏置电路馈电；
    所述功率放大器用于对所述第一输入电流进行放大，并将放大后的第一输入电流输入至所述滤波器。
PCT/CN2024/070232 2023-06-09 2024-01-02 一种保护电路及放大电路 WO2024250662A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202310682633.4 2023-06-09
CN202310682633.4A CN116436418B (zh) 2023-06-09 2023-06-09 一种保护电路及放大电路

Publications (1)

Publication Number Publication Date
WO2024250662A1 true WO2024250662A1 (zh) 2024-12-12

Family

ID=87083605

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2024/070232 WO2024250662A1 (zh) 2023-06-09 2024-01-02 一种保护电路及放大电路

Country Status (2)

Country Link
CN (1) CN116436418B (zh)
WO (1) WO2024250662A1 (zh)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116418315B (zh) * 2023-06-09 2023-12-19 尚睿微电子（上海）有限公司 一种滤波器温度模拟电路
CN116436418B (zh) * 2023-06-09 2023-09-08 尚睿微电子（上海）有限公司 一种保护电路及放大电路
CN117691961A (zh) * 2023-12-22 2024-03-12 尚睿微电子（上海）有限公司 一种过流保护电路和放大器

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080191794A1 (en) * 2007-02-08 2008-08-14 Mediatek Inc. Method and apparatus for tuning an active filter
CN101557203A (zh) * 2009-03-20 2009-10-14 深圳市民展科技开发有限公司 一种具有过流保护的功率放大器
CN102075148A (zh) * 2011-01-13 2011-05-25 惠州市正源微电子有限公司 射频功率放大器过温保护电路
CN112653319A (zh) * 2020-12-10 2021-04-13 中国科学院微电子研究所 一种隔离驱动电路的接收电路
CN114447890A (zh) * 2022-02-10 2022-05-06 广东省大湾区集成电路与系统应用研究院 驱动保护电路及电子芯片
CN116009641A (zh) * 2022-12-31 2023-04-25 尚睿微电子（上海）有限公司 一种电流镜电路、保护电路、偏置电路及电子设备
CN116436418A (zh) * 2023-06-09 2023-07-14 尚睿微电子（上海）有限公司 一种保护电路及放大电路

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1249844B (it) * 1991-10-18 1995-03-28 Sgs Thomson Microelectronics Amplificatore di potenza, in particolare di tipo audio.
JP2001308683A (ja) * 2000-04-18 2001-11-02 Asahi Kasei Microsystems Kk Ｇｍ−Ｃフィルタ
CN104967425A (zh) * 2015-07-21 2015-10-07 海宁市丰达电子有限公司 一种双极型低通滤波器
CN107332520B (zh) * 2017-07-24 2024-03-19 尚睿微电子（上海）有限公司 一种偏置电路及功率放大电路
US10903802B2 (en) * 2019-02-01 2021-01-26 Texas Instruments Incorporated Analog based speaker thermal protection in class-D amplifiers
US11569784B2 (en) * 2021-05-31 2023-01-31 Richwave Technology Corp. Power amplifier capable of maintaining constant gain regardless of temperature variations
CN114825563B (zh) * 2022-06-30 2022-10-04 苏州贝克微电子股份有限公司 一种具有温度保护的电路结构
CN115543000B (zh) * 2022-09-30 2025-05-06 中国兵器工业集团第二一四研究所苏州研发中心 一种适用于超低功耗线性稳压器的过温保护电路

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080191794A1 (en) * 2007-02-08 2008-08-14 Mediatek Inc. Method and apparatus for tuning an active filter
CN101557203A (zh) * 2009-03-20 2009-10-14 深圳市民展科技开发有限公司 一种具有过流保护的功率放大器
CN102075148A (zh) * 2011-01-13 2011-05-25 惠州市正源微电子有限公司 射频功率放大器过温保护电路
CN112653319A (zh) * 2020-12-10 2021-04-13 中国科学院微电子研究所 一种隔离驱动电路的接收电路
CN114447890A (zh) * 2022-02-10 2022-05-06 广东省大湾区集成电路与系统应用研究院 驱动保护电路及电子芯片
CN116009641A (zh) * 2022-12-31 2023-04-25 尚睿微电子（上海）有限公司 一种电流镜电路、保护电路、偏置电路及电子设备
CN116436418A (zh) * 2023-06-09 2023-07-14 尚睿微电子（上海）有限公司 一种保护电路及放大电路

Also Published As

Publication number Publication date
CN116436418B (zh) 2023-09-08
CN116436418A (zh) 2023-07-14

Similar Documents

Publication Publication Date Title
WO2024250662A1 (zh) 一种保护电路及放大电路
WO2024141108A1 (zh) 一种电流镜电路、保护电路、偏置电路及电子设备
CN106357227B (zh) 功率放大模块
CN109917846B (zh) 稳压电路、半导体装置以及电源装置
KR100547236B1 (ko) 전력증폭기에서의 바이어스 안정화 회로
US10014826B2 (en) Apparatus and methods for power enhancement of self-biased distributed amplifiers with gate bias networks
WO2024250663A1 (zh) 一种滤波器温度模拟电路
US11177777B2 (en) Temperature detection circuit, power amplification circuit, and electronic device
CN113411055B (zh) 偏置电流控制装置、射频放大器、电子设备及芯片
WO2021138769A1 (zh) 一种放大电路、补偿方法及雷达
CN114355027A (zh) 一种检测电路及芯片
KR101015049B1 (ko) 공정 드리프트에 대한 보정 기능을 가지는 온도 센서 회로 및 그 방법
CN114265462B (zh) 一种带隙基准、芯片、电子器件及电子设备
US5917382A (en) Sensor of the instant power dissipated in a power transistor
CN210221328U (zh) 温度检测模块、温度监控电路以及功率芯片
US4308504A (en) Direct-coupled amplifier circuit with DC output offset regulation
US5300877A (en) Precision voltage reference circuit
US6664856B2 (en) Circuit configuration for setting the operating point of a radiofrequency transistor and amplifier circuit
US9972614B2 (en) Overheat detection circuit and power supply apparatus
CN116075797B (zh) 对数电流-电压转换器
CN109375687B (zh) 一种抗辐照双极温度监测电路
JPS60198907A (ja) トランスレス式プツシユプル出力回路
CN103604516A (zh) 一种温度传感器
JP2017022685A (ja) 電力増幅モジュール
JP6481398B2 (ja) 検波器及び通信装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24818201

Country of ref document: EP

Kind code of ref document: A1