Bias detection circuit and device

Abstract

The utility model is applied to the technical field of audio, and discloses a bias detection circuit and device, the bias detection circuit is connected with a control module, and the bias detection circuit comprises a filtering module which is used for accessing a first audio end and a second audio end of a power amplifier, receiving a first audio voltage of the first audio end and a second voltage of the second audio end, and outputting the first audio voltage and the second audio voltage; after the first audio voltage and the second audio voltage are filtered respectively, first direct-current voltage and second direct-current voltage are output; the detection module is connected with the filtering module and is used for receiving the first direct-current voltage and the second direct-current voltage and outputting a driving signal when detecting that the voltage difference between the first direct-current voltage and the second direct-current voltage is greater than a preset bias voltage; the driving module is respectively connected with the detection module and the control module, the driving module is used for receiving the driving signal and outputting a bias protection signal of the driving signal, the bias protection signal is used for protecting the power amplifier, and the technical problem of how to carry out DC bias detection on the output of the power amplifier is solved.

Description

Technical Field

[0001] The present application relates to the field of audio technology, and in particular to a bias detection circuit and device. Background Art

[0002] At present, in audio products such as BT Speaker (Bluetooth speaker), WI FI speaker (wireless speaker), S-BAR (Star Ring smart sound bar), the power amplifier IC (Integrated Circuit) already has over-current, over-temperature, over-voltage and other detection and corresponding protection circuits. However, in traditional technology, there is no DC (direct current) bias detection for the output of the power amplifier, and thus, DC bias protection cannot be performed on the output of the power amplifier. Utility Model Content

[0003] The main purpose of the present application is to provide a bias detection circuit and device, aiming to solve the technical problem of how to perform DC bias detection on the output of a power amplifier.

[0004] To achieve the above object, the present application provides a bias detection circuit, the bias detection circuit is connected to a control module, and the bias detection circuit includes:

[0005] A filtering module, the filtering module is used to connect to the first audio terminal and the second audio terminal of the power amplifier, receive the first audio voltage of the first audio terminal and the second voltage of the second audio terminal, filter the first audio voltage and the second audio voltage respectively, and output a first DC voltage and a second DC voltage;

[0006] a detection module, the detection module being connected to the filter module, and configured to receive the first DC voltage and the second DC voltage, and output a driving signal when detecting that a voltage difference between the first DC voltage and the second DC voltage is greater than a preset bias voltage;

[0007] A driving module, the driving module is connected to the detection module and the control module respectively, the driving module is used to receive the driving signal and output a bias protection signal of the driving signal, so that the control module can protect the power amplifier based on the bias protection signal.

[0008] Optionally, the filtering module includes:

[0009] a first filtering unit, the first filtering unit being connected to the first audio terminal and the detection module respectively, and outputting a first DC voltage to the detection module after filtering the first audio voltage;

[0010] The second filtering unit is connected to the first audio terminal and the detection module respectively, and outputs a second DC voltage to the detection module after filtering the second audio voltage.

[0011] Optionally, the detection module includes:

[0012] A first triode, wherein a base of the first triode is connected to the first filtering unit, an emitter of the first triode is connected to the second filtering unit, and a collector of the first triode is connected to the driving module;

[0013] A third resistor, wherein a first end of the third resistor is connected to the collector of the first transistor, and a second end of the third resistor is connected to the power supply end of the power amplifier.

[0014] Optionally, the first filtering unit includes:

[0015] a first resistor, wherein a first end of the first resistor is connected to the first audio terminal, and a second end of the first resistor is connected to the detection module;

[0016] A first capacitor, wherein a first end of the first capacitor is connected to a second end of the first resistor, and a second end of the first capacitor is grounded.

[0017] Optionally, the second filtering unit includes:

[0018] a second resistor, wherein a first end of the second resistor is connected to the second audio end, and a second end of the second resistor is connected to the detection module;

[0019] A second capacitor, wherein a first end of the second capacitor is connected to a second end of the second resistor, and a second end of the second capacitor is grounded.

[0020] Optionally, the base of the first transistor is connected to the second end of the first resistor, the emitter of the first transistor is connected to the second end of the second resistor, and the collector of the first transistor is connected to the driving module; a third resistor, the first end of the third resistor is connected to the collector of the first transistor, and the second end of the third resistor is connected to the power supply end of the power amplifier.

[0021] Optionally, the detection module further includes:

[0022] A voltage regulating unit, wherein a first end of the voltage regulating unit is connected to the emitter of the first transistor, and a second end of the voltage regulating unit is connected to the second end of the second resistor.

[0023] Optionally, the voltage regulating unit includes:

[0024] A second triode, wherein the base of the second triode is respectively connected to the collector of the second triode and the emitter of the first triode, and the emitter of the second triode is connected to the second end of the second resistor and is grounded.

[0025] Optionally, the driving module includes:

[0026] a fourth resistor, a first end of the fourth resistor being connected to the collector of the first transistor;

[0027] a fifth resistor, a first end of the fifth resistor being connected to the second end of the fourth resistor, and a second end of the fifth resistor being grounded;

[0028] a third triode, wherein the base of the third triode is connected to the second end of the fourth resistor, and the emitter of the third triode is grounded;

[0029] A sixth resistor, wherein a first end of the sixth resistor is connected to the collector of the third transistor, a second end of the sixth resistor is connected to a preset reference voltage, and a first end of the sixth resistor is used to output a bias protection signal.

[0030] In addition, to achieve the above-mentioned purpose, the present application provides a bias detection device, which includes the bias detection circuit as described above.

[0031] The present application provides a bias detection circuit, the bias detection circuit is connected to a control module, and the bias detection circuit includes: the bias detection circuit is connected to the control module, and the bias detection circuit includes: a filter module, the filter module is used to access the first audio terminal and the second audio terminal of the power amplifier, receive the first audio voltage of the first audio terminal and the second voltage of the second audio terminal, filter the first audio voltage and the second audio voltage respectively, and output the first DC voltage and the second DC voltage; a detection module, the detection module is connected to the filter module, and is used to receive the first DC voltage and the second DC voltage, and output a driving signal when it is detected that the voltage difference between the first DC voltage and the second DC voltage is greater than a preset bias voltage; a driving module, the driving module is connected to the detection module and the control module respectively, and the driving module is used to receive the driving signal and output a bias protection signal of the driving signal, so that the control module can protect the power amplifier based on the bias protection signal. The present application achieves the effect of bias protection of the power amplifier by outputting a bias protection signal when detecting that the bias voltage is greater than the preset bias voltage, so that the control module can protect the power amplifier based on the bias protection signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of a bias detection circuit provided in one embodiment of the present application;

[0033] Figure 2 A schematic diagram of the structure of a filter module in a bias detection circuit provided in an embodiment of the present application;

[0034] Figure 3 A detailed structural diagram of a filter module in a bias detection circuit provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of the structure of a detection module in a bias detection circuit provided in an embodiment of the present application;

[0036] Figure 5 A detailed structural diagram of a detection module in a bias detection circuit provided in an embodiment of the present application;

[0037] Figure 6 A detailed structural diagram of a voltage regulating unit in a bias detection circuit provided in an embodiment of the present application;

[0038] Figure 7 A schematic diagram of the structure of a driving module in a bias detection circuit provided in an embodiment of the present application;

[0039] FIG8(A) is a schematic diagram of an application of a bias detection circuit provided in an embodiment of the present application;

[0040] FIG8(B) is a schematic diagram of an application of a bias detection circuit provided in another embodiment of the present application.

[0041] Description of Figure Numbers:

[0042] Label name Label name 10 Filter module 20 Detection module 30 Driver module 11 The first filter unit 12 The second filter unit 21 Voltage regulating unit Q1-Q3 First-third transistor R1-R5 The first to fifth resistors C1-C2 First-second capacitor

[0043] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0044] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0047] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0049] At present, in audio products such as BT Speaker (Bluetooth speaker), WIFI speaker (wireless speaker), S-BAR (Star Ring smart sound bar), the power amplifier IC (Integrated Circuit) already has over-current, over-temperature, over-voltage and other detection and corresponding protection circuits. However, in traditional technology, there is no DC (direct current) bias detection for the output of the power amplifier, and thus, DC bias protection cannot be performed on the output of the power amplifier.

[0050] Based on this, the present application proposes a bias detection circuit and device, wherein the bias detection circuit includes: a filtering module, a detection module and a driving module. The present application outputs a bias protection signal when it detects that the bias voltage is greater than a preset bias voltage, so that the control module protects the power amplifier based on the bias protection signal, thereby achieving the effect of bias protection of the power amplifier.

[0051] The present application provides a bias detection circuit, referring to Figure 1 , Figure 1This is a schematic diagram of the structure of a bias detection circuit provided in an embodiment of the present application. The bias detection circuit is connected to a control module, and the bias detection circuit includes:

[0052] A filter module 10, the filter module 10 is used to connect to a first audio terminal and a second audio terminal of the power amplifier, receive a first audio voltage of the first audio terminal and a second voltage of the second audio terminal, filter the first audio voltage and the second audio voltage respectively, and output a first DC voltage and a second DC voltage;

[0053] a detection module 20, the detection module 20 being connected to the filter module 10, and configured to receive the first DC voltage and the second DC voltage, and output a driving signal when detecting that a voltage difference between the first DC voltage and the second DC voltage is greater than a preset bias voltage;

[0054] The driving module 30 is connected to the detection module 20, and is used to receive the driving signal and output a bias protection signal of the driving signal, so that the control module can protect the power amplifier based on the bias protection signal.

[0055] In this embodiment, the filtering module 10 obtains the first audio voltage of the first audio terminal and the second audio voltage of the second audio terminal, filters the first audio voltage and the second audio voltage, filters out the AC voltage output by the power amplifier, and retains the DC (direct current) bias voltage, that is, sends the first DC voltage obtained after filtering and the second DC voltage obtained after filtering to the detection module 20 respectively, and the detection module 20 uses the voltage difference between the first DC voltage and the second DC voltage as the DC bias voltage of the power amplifier, and compares the bias voltage with the preset bias voltage. When it is detected that the bias voltage is greater than the preset bias voltage, the driving module 30 outputs a driving signal, and the driving module 30 outputs a bias protection signal after receiving the driving signal. After receiving the bias protection signal, the control module takes bias protection measures for the power amplifier. It should be noted that the bias protection voltage can be a high level or a low level.

[0056] Exemplarily, the filter module 10 is connected to the audio output terminal of the power amplifier, the audio output terminal may be a first audio terminal and a second audio terminal, the first audio terminal and the second audio terminal may be L+ and L-. That is, the first audio terminal is L+, the second audio terminal is L-, the first audio terminal is L-, and the second audio terminal is L+. Under normal circumstances, V L+ =V L- , no bias voltage is generated at this time. This bias detection circuit is used when the voltage at the first audio terminal is greater than the voltage at the second audio terminal. In actual applications, if V L+ ﹥V LWhen L+ is used as the first audio terminal, L- is used as the second audio terminal. L+ ﹤V L When the bias voltage is greater than the preset bias voltage, the present application outputs a bias protection signal, so that the control module can protect the power amplifier based on the bias protection signal, thereby achieving the bias protection effect of the power amplifier.

[0057] It should be noted that the audio voltage and the filtered DC voltage have the same voltage value.

[0058] Optionally, in some feasible embodiments, reference Figure 2 , Figure 2 This is a schematic diagram of the structure of a filter module in a bias detection circuit provided in an embodiment of the present application. The filter module 10 includes:

[0059] A first filtering unit 11, wherein the first filtering unit 11 is connected to the first audio terminal and the detection module 20 respectively, and outputs a first DC voltage to the detection module 20 after filtering the first audio voltage;

[0060] The second filtering unit 12 is connected to the first audio terminal 12 and the detection module 20 respectively, and outputs a second DC voltage to the detection module 20 after filtering the second audio voltage.

[0061] In this embodiment, the first filtering unit 11 filters the first audio voltage input from the first audio end, that is, after filtering out the AC component in the first audio voltage, the DC component in the first audio voltage is sent to the detection module 20 as the first DC voltage; the second filtering unit 12 filters the second audio voltage input from the second audio end, that is, after filtering out the AC component in the second audio voltage, the DC component in the second audio voltage is sent to the detection module 20 as the second DC voltage.

[0062] Optionally, in some feasible embodiments, reference Figure 3 , Figure 3 This is a detailed structural diagram of a filter module in a bias detection circuit provided in an embodiment of the present application, wherein the first filter unit 11 includes:

[0063] A first resistor R1, wherein a first end of the first resistor R1 is connected to the first audio terminal, and a second end of the first resistor R1 is connected to the detection module 20;

[0064] A first capacitor C1 , wherein a first end of the first capacitor C1 is connected to a second end of the first resistor R1 , and a second end of the first capacitor C1 is grounded.

[0065] In this embodiment, the first resistor R1 and the first capacitor C1 form a low-pass filter to filter out the AC component of the power amplifier output voltage, F (frequency) = 1 / 2πRC. If the first resistor R1 is 10K and the first capacitor C1 is 220UF, the frequency is 0.1HZ. Since the audio signal range is 20-20KHZ, the bias voltage can be retained after filtering by the low-pass filter composed of the first resistor R1 and the first capacitor C1.

[0066] Optionally, in some feasible embodiments, reference Figure 3 , the second filtering unit 12 includes:

[0067] a second resistor R2, wherein a first end of the second resistor R2 is connected to the second audio end, and a second end of the second resistor R2 is connected to the detection module 20;

[0068] A second capacitor C2, wherein a first end of the second capacitor C2 is connected to a second end of the second resistor R2, and a second end of the second capacitor C2 is grounded.

[0069] In this embodiment, the second resistor R2 and the second capacitor C2 also form a low-pass filter to filter out the AC component of the power amplifier output voltage, F (frequency) = 1 / 2πRC. If the second resistor R2 is 10K and the second capacitor C2 is 220UF, the frequency is 0.1HZ. Since the audio signal range is 20-20KHZ, the bias voltage is retained after filtering by the low-pass filter composed of the second resistor R2 and the second capacitor C2.

[0070] Optionally, in some feasible embodiments, the detection module 20 includes:

[0071] A first transistor Q1, wherein the base of the first transistor Q1 is connected to the first filtering unit 11, the emitter of the first transistor Q1 is connected to the second filtering unit 12, and the collector of the first transistor Q1 is connected to the driving module 30;

[0072] A third resistor R3, wherein a first end of the third resistor R3 is connected to the collector of the first transistor Q1, and a second end of the third resistor R3 is connected to the power supply end of the power amplifier.

[0073] Specifically, refer to Figure 4 , Figure 4This is a detailed structural schematic diagram of the detection module in the bias detection circuit provided in an embodiment of the present application, wherein the base of the first transistor Q1 is connected to the second end of the first resistor R1, the emitter of the first transistor Q1 is connected to the second end of the second resistor R2, and the collector of the first transistor Q1 is connected to the driving module 30; the first end of the third resistor R3 is connected to the collector of the first transistor Q1, and the second end of the third resistor R3 is connected to the power supply end PVDD of the power amplifier.

[0074] In this embodiment, the first transistor Q1 is turned on when it is detected that the voltage difference between the base voltage and the emitter voltage is greater than the conduction condition of the first transistor Q1. After being turned on, the voltage of the first end of the third resistor R3 is pulled down, thereby sending a low level to the driving module 30.

[0075] For example, the on-state voltage V of the first transistor Q1 is be The bias voltage is preset to be 0.6V at this time. Therefore, when the voltage difference between the first DC voltage and the second DC voltage is greater than 0.6V, the first transistor Q1 is turned on, thereby sending a low level to the driving module 30. The power amplifier IC generates a lot of heat when working. The on-voltage of the first transistor Q1 in the present application is less affected by temperature, thereby reducing the cost while improving the performance stability, and realizing the effect of detecting the output DC bias of the power amplifier at a very low cost.

[0076] It should be noted that in the present embodiment, the first transistor Q1 is an NPN transistor. If the voltage applied to the first audio terminal is greater than the voltage applied to the second audio terminal, the first transistor Q1 can be a PNP transistor to achieve application in a scenario where the first audio voltage is less than the second audio voltage.

[0077] Optionally, in some feasible embodiments, reference Figure 5 , Figure 5 This is a detailed structural diagram of a detection module in a bias detection circuit provided in an embodiment of the present application, wherein the detection module 20 further includes:

[0078] A voltage regulating unit 21 , wherein a first end of the voltage regulating unit 21 is connected to the emitter of the first transistor Q1 , and a second end of the voltage regulating unit 21 is connected to the second end of the second resistor R2 .

[0079] In this embodiment, the first DC voltage is transmitted to the base of the first transistor Q1, and the second DC voltage is transmitted to the second end of the voltage regulating unit 21. The voltage regulating unit 21 is turned on when it is detected that the voltage difference between the first end and the second end of the voltage regulating unit 21 is greater than the conduction condition of the voltage regulating unit 21, and the voltage regulating unit 21 is turned on when the voltage difference between the base and the emitter of the first transistor Q1 is greater than the conduction condition of the first transistor Q1. Therefore, when the voltage difference between the first DC voltage and the second DC voltage simultaneously satisfies the conduction conditions of the voltage regulating unit 21 and the first transistor, the first transistor Q1 and the voltage regulating unit 21 are turned on at the same time, thereby lowering the voltage of the collector of the first transistor Q1 to send a low level to the driving module 30. That is to say, the voltage regulating unit 21 is used to adjust the size of the preset bias voltage, thereby adjusting the accuracy of the bias voltage of the detection amplifier, that is, the sum of the on-condition voltage of the voltage regulating unit 21 and the on-condition voltage of the first transistor Q1 is the adjusted preset bias voltage, and when the bias voltage is greater than the adjusted preset bias voltage, a low level is sent to the driving module 30.

[0080] Optionally, in some feasible embodiments, reference Figure 6 , Figure 6 This is a detailed structural diagram of a voltage regulating unit in a bias detection circuit provided in an embodiment of the present application, wherein the voltage regulating unit 21 includes:

[0081] A second transistor Q2, wherein the base of the second transistor Q2 is respectively connected to the collector of the second transistor Q2 and the emitter of the first transistor Q1, and the emitter of the second transistor Q2 is connected to the second end of the second resistor R2 and is grounded.

[0082] In this embodiment, the voltage regulating unit 21 may be a second transistor Q2. Since the conduction voltage of the transistor is less affected by temperature, the preset reference voltage can be accurately adjusted. be It is also 0.6V. When the voltage difference between the base of the second transistor Q2 and the emitter of the second transistor Q2 is greater than 0.6V, the second transistor Q2 is turned on. At the same time, when the voltage difference between the base of the first transistor Q1 and the emitter of the first transistor Q1 is greater than 0.6V, the first transistor Q1 is turned on. Therefore, when the voltage difference between the first DC voltage and the second DC voltage is greater than 1.2V (0.6V+0.6V), the first transistor Q1 and the second transistor Q2 are turned on at the same time, thereby pulling down the voltage of the collector of the first transistor to send a low level to the driving module 30. At this time, the adjusted preset reference voltage is 1.2V.

[0083] Under normal circumstances, the first audio voltage and the second audio voltage are the same, and the first transistor Q1 and the second transistor Q2 cannot be turned on at the same time. At this time, a low level cannot be sent to the driving module 30. When the voltage difference between the first audio voltage and the second audio voltage is greater than the adjusted preset reference voltage, the first transistor Q1 and the second transistor Q2 are turned on, and a low level is sent to the driving module 30.

[0084] It should be noted that the voltage regulating unit 21 may include one or more second transistors Q2, so as to adjust the preset reference voltage.

[0085] Optionally, in some feasible embodiments, reference Figure 7 , Figure 7 This is a schematic diagram of the structure of a driving module in a bias detection circuit provided in an embodiment of the present application, wherein the driving module 30 includes:

[0086] a fourth resistor R4, wherein a first end of the fourth resistor R4 is connected to the collector of the first transistor Q1;

[0087] a fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to a second end of the fourth resistor R4, and a second end of the fifth resistor R5 is grounded;

[0088] a third triode Q3, wherein the base of the third triode Q3 is connected to the second end of the fourth resistor R4, and the emitter of the third triode Q3 is grounded;

[0089] A sixth resistor R6, a first end of the sixth resistor R6 is connected to the collector of the third transistor Q3, a second end of the sixth resistor R6 is connected to a preset reference voltage, and a first end of the sixth resistor R6 is used to output a bias protection signal.

[0090] In this embodiment, two implementation situations are provided. In the first situation, if the third transistor Q3 is a PNP transistor, the bias protection signal is at a low level, and the PNP transistor is turned on at a low voltage. Specifically, when the voltage difference between the first DC voltage and the second DC voltage is greater than the preset bias voltage, the first transistor Q1 is turned on, and the collector voltage of the first transistor Q1 is pulled down, so that the third transistor Q3 is turned on. At this time, the collector voltage of the third transistor Q3 is pulled down, and the output bias protection signal is at a low level.

[0091] If the third transistor Q3 is an NPN transistor, the bias protection signal is at a high level, and the NPN transistor is turned on at a high voltage. Specifically, when the voltage difference between the first DC voltage and the second DC voltage is greater than the preset bias voltage, the first transistor Q1 is turned on, and the collector voltage of the first transistor Q1 is pulled down, so that the third transistor Q3 is turned off. At this time, the collector voltage of the third transistor Q3 cannot be pulled down, and the output bias protection signal is at a high level.

[0092] In addition, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 act as voltage divider resistors. The preset reference voltage Ref1 can be a power supply terminal of the control module, specifically 1.8V or 3.3V, or can be a voltage obtained by voltage conversion based on the power supply terminal PVDD of the power amplifier.

[0093] Referring to FIG8(A) and FIG8(B), FIG8(A) is an application diagram of a bias detection circuit provided by an embodiment of the present application, wherein the first audio terminal is L+, and the second audio terminal is L-. When the voltage difference between the voltage of L+ and the voltage of L- is greater than the preset bias voltage, a bias protection signal protect is output. The conduction voltage of the first transistor Q1 is 0.6V at room temperature, and the conduction voltage of the second transistor Q1 is 0.6V at room temperature. That is, if the first audio voltage V L+ than the second audio voltage V L- When the voltage is higher than 1.2V, V L+ =V b , V L- =Ve, so that the first transistor Q1 is turned on and the bias protection signal protect is output. FIG8(B) is an application diagram of the bias detection circuit provided by another embodiment of the present application, in which the first audio terminal is L-, and the second audio terminal is L+. When the voltage difference between the voltage of L- and the voltage of L+ is greater than the preset bias voltage, the bias protection signal protect is output. That is, if the second audio voltage V L- than the first audio voltage V L+ When it is higher than 1.2V, the first transistor Q1 is turned on and the bias protection signal protect is output.

[0094] The present application also proposes a bias detection device, which includes a bias detection circuit. The specific structure of the bias detection circuit refers to the above-mentioned embodiment. Since the present optimized bias detection device adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0095] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0096] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0097] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a computer storage medium (such as Flash memory, ROM / RAM, disk, CD), including several instructions for enabling a controller in a terminal device (which can be a mobile phone, computer, server, or network device, etc.) for controlling the storage medium to perform data read and write operations to execute the methods described in each embodiment of the present application.

[0098] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A bias detection circuit, characterized in that: The bias detection circuit is connected to the control module, and the bias detection circuit includes: a filtering module, the filtering module being connected to the first audio terminal and the second audio terminal of the power amplifier, and being used for receiving a first audio voltage of the first audio terminal and a second audio voltage of the second audio terminal, filtering the first audio voltage and the second audio voltage respectively, and outputting a first DC voltage and a second DC voltage; a detection module, the detection module being connected to the filter module, and configured to receive the first DC voltage and the second DC voltage, and output a driving signal when detecting that a voltage difference between the first DC voltage and the second DC voltage is greater than a preset bias voltage; A driving module, the driving module is connected to the detection module and the control module respectively, the driving module is used to receive the driving signal and output a bias protection signal of the driving signal, so that the control module can protect the power amplifier based on the bias protection signal.

2. The bias detection circuit according to claim 1, wherein: The filtering module comprises: a first filtering unit, the first filtering unit being connected to the first audio terminal and the detection module respectively, and outputting a first DC voltage to the detection module after filtering the first audio voltage; The second filtering unit is connected to the first audio terminal and the detection module respectively, and outputs a second DC voltage to the detection module after filtering the second audio voltage.

3. The bias detection circuit according to claim 2, wherein: The detection module comprises: A first triode, wherein a base of the first triode is connected to the first filtering unit, an emitter of the first triode is connected to the second filtering unit, and a collector of the first triode is connected to the driving module; A third resistor, wherein a first end of the third resistor is connected to the collector of the first transistor, and a second end of the third resistor is connected to the power supply end of the power amplifier.

4. The bias detection circuit according to claim 3, characterized in that: The first filtering unit comprises: a first resistor, wherein a first end of the first resistor is connected to the first audio terminal, and a second end of the first resistor is connected to the detection module; A first capacitor, wherein a first end of the first capacitor is connected to a second end of the first resistor, and a second end of the first capacitor is grounded.

5. The bias detection circuit according to claim 4, characterized in that: The second filtering unit comprises: a second resistor, wherein a first end of the second resistor is connected to the second audio end, and a second end of the second resistor is connected to the detection module; A second capacitor, wherein a first end of the second capacitor is connected to a second end of the second resistor, and a second end of the second capacitor is grounded.

6. The bias detection circuit according to claim 5, characterized in that: The control end base of the first transistor is connected to the second end of the first resistor, the first end emitter of the first transistor is connected to the second end of the second resistor, and the collector of the first transistor is connected to the driving module; the first end of the third resistor is connected to the second end collector of the first transistor, and the second end of the third resistor is connected to the power supply end of the power amplifier.

7. The bias detection circuit according to claim 6, wherein: The detection module also includes: A voltage regulating unit, wherein a first end of the voltage regulating unit is connected to the emitter of the first transistor, and a second end of the voltage regulating unit is connected to the second end of the second resistor.

8. The bias detection circuit according to claim 7, wherein: The voltage regulating unit comprises: At least one second triode, the base of the second triode is respectively connected to the collector of the second triode and the emitter of the first triode, and the emitter of the second triode is connected to the second end of the second resistor and is grounded.

9. The bias detection circuit according to claim 8, characterized in that: The driving module comprises: a fourth resistor, a first end of the fourth resistor being connected to the collector of the first transistor; a fifth resistor, a first end of the fifth resistor being connected to the second end of the fourth resistor, and a second end of the fifth resistor being grounded; a third triode, wherein the base of the third triode is connected to the second end of the fourth resistor, and the emitter of the third triode is grounded; A sixth resistor, wherein a first end of the sixth resistor is connected to the collector of the third transistor, a second end of the sixth resistor is connected to a preset reference voltage, and a first end of the sixth resistor is used to output a bias protection signal.

10. A bias detection device, characterized in that: The bias detection device comprises a bias detection circuit as described in any one of claims 1-9.

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