CN113126668A - High-temperature protection circuit structure of audio power amplifier circuit - Google Patents
High-temperature protection circuit structure of audio power amplifier circuit Download PDFInfo
- Publication number
- CN113126668A CN113126668A CN201911408836.4A CN201911408836A CN113126668A CN 113126668 A CN113126668 A CN 113126668A CN 201911408836 A CN201911408836 A CN 201911408836A CN 113126668 A CN113126668 A CN 113126668A
- Authority
- CN
- China
- Prior art keywords
- resistor
- kth
- temperature
- unit
- gain
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D23/00—Control of temperature
- G05D23/19—Control of temperature characterised by the use of electric means
- G05D23/20—Control of temperature characterised by the use of electric means with sensing elements having variation of electric or magnetic properties with change of temperature
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Amplifiers (AREA)
Abstract
The invention relates to a high-temperature protection circuit structure of an audio power amplifier circuit, which comprises a temperature detection module and a gain adjustment module, wherein the temperature detection module outputs a corresponding gain adjustment signal along with the change of temperature, and the gain adjustment module is used for carrying out gain adjustment according to the gain adjustment signal output by the temperature detection module. By adopting the high-temperature protection circuit structure of the audio power amplifier circuit, the gain of the power amplifier at different temperatures is changed by monitoring the temperature, so that the problems of circuit loss and sound interruption of the temperature protection turn-off power amplifier due to switch switching caused by temperature change caused by continuous temperature rise can be effectively avoided; the circuit structure carries out real-time monitoring on the temperature, continuously processes the over-temperature signal and changes the gain of the power amplifier, so that the distortion degree of the input audio signal is not changed, and the hearing experience is improved.
Description
Technical Field
The invention relates to the technical field of circuit structures, in particular to the field of high-temperature processing of circuits, and particularly relates to a high-temperature protection circuit structure of an audio power amplifier circuit.
Background
At present, power amplifier products are popularized in life, and various products exist in the market, wherein the power amplifier is directly closed after the temperature of a circuit rises, or the products are controlled by changing audio signals; when the product works, along with the prolonging of the working time of the power amplifier circuit or the rising of the temperature of the working environment, the rising of the temperature inside the circuit can be caused to trigger the temperature protection, and the temperature protection comprises the following two processing modes:
the first is to directly close the power amplifier and do not work until the temperature is recovered and the power amplifier recovers to work; the operation mode can lead to repeated and intermittent sound and poor listening experience;
the second is a temperature protection trigger protection signal, which causes the power amplifier to continue working but causes distortion to increase by pulling down the amplitude of the audio signal.
The following exemplary embodiments of the present invention are described below:
1) the temperature-sensitive resistor is used for detecting and connecting the temperature-sensitive resistor to the feedback resistor in parallel, and when the temperature changes, the total feedback resistance value changes to change the gain;
2) a temperature detection module is added outside the chip and is placed on the radiator, and the temperature reduction detection value is converted into current to change the voltage at one end of the comparator;
3) the method for changing the gain by connecting the temperature-sensitive resistor in parallel to the feedback resistor comprises the following steps: the temperature-sensitive resistor has larger resistance change along with the temperature change, the temperature-sensitive resistor is connected to the feedback resistor in parallel to cause the feedback resistor to have larger resistance change along with the temperature, although the gain at high temperature can be improved, the gain change is larger, the sound volume change on hearing is larger, and the gain value of the method depends on the temperature-sensitive resistor to be difficult to control;
4) the method comprises the following steps of: the temperature of the radiating fin detected by the method is fed back to the chip to control the gain of the chip, and the actually detected temperature of the radiating fin is possibly lower than the temperature of the chip due to a certain error between the radiating fin and the actual temperature inside the chip, so that the detection error is caused, and the circuit is possibly burnt out. The method of externally arranging the cooling fin temperature detection module has low circuit integration level and increases the cost of customers.
Disclosure of Invention
The invention aims to overcome at least one defect of the prior art and provides a high-temperature protection circuit structure of an audio power amplifier circuit, which has the advantages of low loss, good safety and wide application range.
In order to achieve the above object, the high temperature protection circuit structure of the audio power amplifier circuit of the present invention is as follows:
the high-temperature protection circuit structure of the audio power amplifier circuit is mainly characterized in that the circuit structure comprises:
the temperature detection module is used for outputting a corresponding gain adjustment signal along with the change of the temperature;
the gain adjusting module is connected with the temperature detecting module and is used for adjusting the gain according to the gain adjusting signal;
the temperature detection module comprises a first resistor string and n +1 temperature detection comparison units, the first resistor string comprises n +2 first resistors which are connected in series, a node between every two adjacent first resistors in the first resistor string forms a voltage acquisition point, the first resistor string is connected between detection current and ground in series, and the detection current changes along with the change of the temperature;
the first input end of the kth temperature detection comparison unit is correspondingly connected between the kth first resistor and the (k +1) th first resistor in the first resistor string, the second input end of the kth temperature detection comparison unit is connected with a reference voltage, the kth temperature detection comparison unit is used for comparing the voltage at the kth voltage acquisition point in the first resistor string with the reference voltage, and the output end of the kth temperature detection comparison unit is connected with a gain adjustment module;
the kth temperature detection comparison unit is any one of the n +1 temperature detection comparison units, the kth first resistor is any one of n +2 first resistors connected in series in the first resistor string, the kth voltage acquisition point is a voltage acquisition point formed by a node between the kth first resistor and the kth +1 first resistor in the first resistor string, and n is larger than or equal to 2.
Preferably, the temperature detection module further includes n +1 temperature drop delay recovery units and a second resistor string, the first resistor string is connected in series with the second resistor string and then grounded, and the second resistor string includes n +1 second resistors connected in series;
the first end of the kth temperature drop delay recovery unit is connected with one end, close to the first resistor, of the kth second resistor, the second end of the kth temperature drop delay recovery unit is grounded, and the control end of the kth temperature drop delay recovery unit is connected with the output end of the kth temperature detection comparison unit;
and the control end of the kth temperature drop delay recovery unit receives a signal to determine whether one end of the kth second resistor close to the first resistor is connected with the ground or not.
Preferably, each of the temperature drop delay restoration units includes a first inverter and a first controllable switch, an input end of the first inverter constitutes a control end of the temperature drop delay restoration unit, an output end of the first inverter is connected to an input end of the first controllable switch, a first end of the first controllable switch constitutes a first end of the temperature drop delay restoration unit, and a second end of the first controllable switch constitutes a second end of the temperature drop delay restoration unit.
Preferably, the gain adjusting module includes a gain logic unit and a driving unit, and the gain logic unit includes a first operational amplifier, a fourth resistor, a fifth resistor, and a first gain logic set and a second gain logic set with the same structure;
the first gain logic group and the second gain logic group respectively comprise n short-circuit control units and a third resistor string, and the third resistor string comprises n +2 third resistors connected in series;
the first end of the kth short-circuit control unit is connected with the second end of the kth third resistor in the third resistor string, the second end of the kth short-circuit control unit is connected with the first end of the (n + 2) th third resistor in the third resistor string, the control end of the kth short-circuit control unit is connected with the output end of the kth temperature detection comparison unit, and whether the second end of the kth third resistor is short-circuited with the first end of the (n + 2) th third resistor in the third resistor string through the corresponding kth short-circuit control unit is determined by a signal received by the control end of the kth short-circuit control unit, wherein the kth third resistor is any one of the third resistors in the third resistor string except for the n +2 th third resistor;
a first end of a first one of the third resistors in a third resistor string in the first gain logic set is connected with a first input signal, and a second end of an n +2 th one of the third resistors in the third resistor string in the first gain logic set is connected with a non-inverting input end of the first operational amplifier; a first end of a first one of the third resistors in a third resistor string in the second gain logic group is connected with a second input signal, and a second end of an n +2 th one of the third resistors in the third resistor string in the second gain logic group is connected with an inverting input end of the first operational amplifier;
a first end of the fourth resistor is connected with a non-inverting input end of the first operational amplifier, a second end of the fourth resistor is connected with a first output end of the driving unit, and an inverting output end of the first operational amplifier is connected with the first input end of the driving unit; a first end of the fifth resistor is connected with the inverting input end of the first operational amplifier, a second end of the fifth resistor is connected with the second output end of the driving unit, and the non-inverting output end of the first operational amplifier is connected with the second input end of the driving unit; and the third input end of the driving unit is connected with a pulse signal.
Preferably, the gain logic unit further includes an n +1 th short-circuit control unit, a first end of the n +1 th short-circuit control unit is connected to the non-inverting input terminal of the first operational amplifier, a second end of the n +1 th short-circuit control unit is connected to the inverting output terminal of the first operational amplifier, a control end of the n +1 th short-circuit control unit is connected to an output end of the n +1 th temperature detection comparing unit in the temperature detection module, and a signal received by the control end of the n +1 th short-circuit control unit determines whether the non-inverting input terminal of the first operational amplifier is in short circuit with the inverting output terminal of the first operational amplifier through the n +1 th short-circuit control unit.
Preferably, the gain adjusting module further comprises n control signal converting units for performing signal conversion and generating control signals;
the output end of the kth temperature detection comparison unit is simultaneously connected with the control end of the kth short-circuit control unit in the first gain logic group and the second gain logic group through the corresponding kth control signal conversion unit in the n control signal conversion units;
each control signal conversion unit comprises an OR gate;
the first input end of an OR gate in the kth control signal conversion unit is connected with an external control end, the second input end of the OR gate in the kth control signal conversion unit is connected with the output end of the kth temperature detection comparison unit, and the output end of the OR gate in the kth control signal conversion unit is simultaneously connected with the control end of the kth short-circuit control unit in the first gain logic group and the second gain logic group;
wherein, the kth temperature detection comparing unit is any one of the n +1 temperature detection comparing units except the n +1 temperature detection comparing unit.
Furthermore, each short-circuit control unit is composed of a transmission gate formed by connecting a first PMOS tube and a first NMOS tube in parallel, and a control end of the short-circuit control unit is respectively formed by a grid electrode of the first PMOS tube and a grid electrode of the first NMOS tube;
each control signal conversion unit also comprises a second inverter;
one end of the output end of the OR gate in the kth control signal conversion unit is led out and is directly connected with the grid electrode of the first PMOS tube in the kth short-circuit control unit; one end of the output end of the OR gate in the kth control signal conversion unit is also led out and connected with the grid electrode of the first NMOS tube in the kth short-circuit control unit through the second phase inverter in the control signal conversion unit.
Preferably, the driving unit includes a first comparator, a second comparator and a driving subunit;
the non-inverting input terminal of the first comparator forms the first input terminal of the driving unit, the non-inverting input terminal of the second comparator forms the second input terminal of the driving unit, and the inverting input terminal of the first comparator and the inverting input terminal of the second comparator together form the third input terminal of the driving unit;
the output end of the first comparator is connected with the first input end of the driving subunit, the output end of the second comparator is connected with the second input end of the driving subunit, the first output end of the driving subunit forms the first output end of the driving unit, and the second output end of the driving subunit forms the second output end of the driving unit.
Preferably, each of the temperature detection comparing units includes a third comparator, a non-inverting input terminal of each of the third comparators constitutes the first input terminal of the temperature detection comparing unit, an inverting input terminal of each of the third comparators constitutes the second input terminal of the temperature detection comparing unit, and an output terminal of each of the third comparators constitutes the output terminal of the temperature detection comparing unit.
Preferably, the circuit structure further includes a reference module, where the reference module includes a first triode, a second operational amplifier, a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, a fourth field-effect transistor, a sixth resistor, and a seventh resistor;
the base electrode of the first triode, the collector electrode of the first triode, the base electrode of the second triode and the collector electrode of the second triode are all grounded;
the emitter of the first triode is simultaneously connected with the non-inverting input end of the second operational amplifier, the drain of the third field effect transistor and the first end of the sixth resistor;
an emitter of the second triode is connected with a first end of the seventh resistor, and a second end of the seventh resistor is connected with an inverting input end of the second operational amplifier and a drain electrode of the second field effect transistor at the same time;
the output end of the second operational amplifier is simultaneously connected with the grid electrode of the first field effect transistor, the grid electrode of the second field effect transistor, the grid electrode of the third field effect transistor and the grid electrode of the fourth field effect transistor;
the source electrode of the first field effect transistor, the source electrode of the second field effect transistor, the source electrode of the third field effect transistor and the source electrode of the fourth field effect transistor are all connected with a power supply end;
the area of the first triode is smaller than that of the second triode;
the second end of the sixth resistor is connected with the drain electrode of the fourth field effect transistor, and one end of the sixth resistor is led out from the connection position of the sixth resistor and the fourth field effect transistor and used for outputting the reference voltage;
the grid electrode of the first field effect transistor is connected with the drain electrode of the first field effect transistor, and one end of the grid electrode of the first field effect transistor is led out from the connection position of the grid electrode of the first field effect transistor and the drain electrode of the first field effect transistor and used for outputting the detection current.
By adopting the high-temperature protection circuit structure of the audio power amplifier circuit, when the audio power amplifier circuit works for a long time or the temperature rises, the gain adjusting signal which changes along with the temperature change is output to the gain adjusting module through the temperature detecting module, a basis is provided for the gain adjusting module to adjust the gain, the gain of the power amplifier at different temperatures is changed, the auditory experience is improved, and the problems of circuit loss caused by switch switching and sound interruption of the temperature protection turn-off power amplifier caused by temperature change are avoided; after the temperature continues to rise, the protection signal for turning off the power amplifier can still be triggered, and the protection circuit is burnt out; the circuit has set up several temperature detection comparing element, has realized that the gain of many grades is adjustable, carries out continuous processing to the signal when overtemperature, and simultaneously, circuit structure still includes the temperature decline delay recovery unit that quantity and temperature detection comparing element match, and when the temperature recovery back, the circuit safety can get back to original condition, and this circuit structure effectively makes the distortion rate of the audio signal of input keep unchangeable, has promoted the sense of hearing and has experienced.
Drawings
Fig. 1 is a block diagram of a high temperature protection circuit structure of an audio power amplifier circuit according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a temperature detection module according to an embodiment of the invention.
Fig. 3 is a schematic structural diagram of a reference module according to an embodiment of the invention.
Fig. 4 is a schematic structural diagram of n control signal conversion units in the gain adjustment module according to an embodiment of the invention.
Fig. 5 is a schematic structural diagram of a gain logic unit and a driving unit in a gain adjustment module according to an embodiment of the invention.
Detailed Description
In order to more clearly describe the technical contents of the present invention, the following further description is given in conjunction with specific embodiments.
As shown in fig. 1 to 5, the high temperature protection circuit structure of the audio power amplifier circuit of the present invention includes:
the temperature detection module is used for outputting a corresponding gain adjustment signal along with the change of the temperature;
the gain adjusting module is connected with the temperature detecting module and is used for adjusting the gain according to the gain adjusting signal;
as shown in fig. 2, the temperature detection module includes a first resistor string and n +1 temperature detection comparison units, the first resistor string includes n +2 first resistors connected in series, and a node between every two adjacent first resistors in the first resistor string forms a voltage acquisition point (only nodes a1, a2, an and a are indicated in fig. 2, and all are indicated by ellipses), and the first resistor string is connected in series between a detection current IREF and ground, and the detection current IREF varies with the temperature;
the first input end of the kth temperature detection comparison unit is correspondingly connected between the kth first resistor and the (k +1) th first resistor in the first resistor string, the second input end of the kth temperature detection comparison unit is connected with a reference voltage VREF, the kth temperature detection comparison unit is used for comparing the voltage at the kth voltage acquisition point in the first resistor string with the reference voltage VREF, and the output end of the kth temperature detection comparison unit is connected with a gain adjustment module;
the kth temperature detection comparison unit is any one of the n +1 temperature detection comparison units, the kth first resistor is any one of n +2 first resistors connected in series in the first resistor string, the kth voltage acquisition point is a voltage acquisition point formed by a node between the kth first resistor and the kth +1 first resistor in the first resistor string, and n is larger than or equal to 2.
In this embodiment, each of the temperature detection comparing units includes a third comparator, a non-inverting input terminal of each of the third comparators constitutes a first input terminal of the temperature detection comparing unit, an inverting input terminal of each of the third comparators constitutes a second input terminal of the temperature detection comparing unit, and an output terminal of each of the third comparators constitutes an output terminal of the temperature detection comparing unit, and since the structures of each group of temperature detection comparing units are the same, only the third comparators COMP1, COMP2, COMP and COMP are drawn in fig. 2, and the remaining third comparators are replaced with ellipses.
In this embodiment, the temperature detection module further includes n +1 temperature drop delay recovery units and a second resistor string, the first resistor string is connected in series with the second resistor string and then grounded, and the second resistor string includes n +1 second resistors connected in series;
the first end of the kth temperature drop delay recovery unit is connected with one end, close to the first resistor, of the kth second resistor, the second end of the kth temperature drop delay recovery unit is grounded, and the control end of the kth temperature drop delay recovery unit is connected with the output end of the kth temperature detection comparison unit;
and the control end of the kth temperature drop delay recovery unit receives a signal to determine whether one end of the kth second resistor close to the first resistor is connected with the ground or not.
By arranging the temperature drop delay recovery unit, the reduced temperature can be delayed and recovered to the original temperature, so that the temperature detection has a hysteresis range.
In this embodiment, each of the temperature drop delay recovery units includes a first inverter and a first controllable switch, an input end of the first inverter forms a control end of the temperature drop delay recovery unit, an output end of the first inverter is connected to an input end of the first controllable switch, a first end of the first controllable switch forms a first end of the temperature drop delay recovery unit, and a second end of the first controllable switch forms a second end of the temperature drop delay recovery unit.
As shown in fig. 5, in this embodiment, the gain adjustment module includes a gain logic unit and a driving unit, where the gain logic unit includes a first operational amplifier AMP, a fourth resistor Rf1, a fifth resistor Rf2, and a first gain logic set and a second gain logic set with the same structure;
the first gain logic group and the second gain logic group respectively comprise n short-circuit control units and a third resistor string, and the third resistor string comprises n +2 third resistors connected in series;
the first end of the kth short-circuit control unit is connected with the second end of the kth third resistor in the third resistor string, the second end of the kth short-circuit control unit is connected with the first end of the (n + 2) th third resistor in the third resistor string, the control end of the kth short-circuit control unit is connected with the output end of the kth temperature detection comparison unit, and whether the second end of the kth third resistor is short-circuited with the first end of the (n + 2) th third resistor in the third resistor string through the corresponding kth short-circuit control unit is determined by a signal received by the control end of the kth short-circuit control unit, wherein the kth third resistor is any one of the third resistors in the third resistor string except for the n +2 th third resistor;
a first end of a first one of the third resistors in the third resistor string in the first gain logic set is connected to the first input signal INP, and a second end of an n +2 th one of the third resistors in the third resistor string in the first gain logic set is connected to a non-inverting input terminal of the first operational amplifier AMP; a first end of a first one of the third resistors in a third resistor string in the second gain logic group is connected to the second input signal INN, and a second end of an n +2 th one of the third resistors in the third resistor string in the second gain logic group is connected to the inverting input terminal of the first operational amplifier AMP;
a first terminal of the fourth resistor Rf1 is connected to the non-inverting input terminal of the first operational amplifier AMP, a second terminal of the fourth resistor Rf1 is connected to the first output terminal of the driving unit, and the inverting output terminal of the first operational amplifier AMP is connected to the first input terminal of the driving unit; a first terminal of the fifth resistor Rf2 is connected to the inverting input terminal of the first operational amplifier AMP, a second terminal of the fifth resistor Rf2 is connected to the second output terminal of the driving unit, and the non-inverting output terminal of the first operational amplifier AMP is connected to the second input terminal of the driving unit; the third input end of the driving unit is connected with a pulse signal;
when the temperature is not raised, all the short-circuit control units in the first gain logic group and the second gain logic group are in a short-circuit state, and are sequentially disconnected according to the gain adjusting signals output by the temperature detection module along with the rise of the temperature so as to adjust the gain of the circuit.
In this embodiment, the gain logic unit further includes an n +1 th short-circuit control unit, a first end of the n +1 th short-circuit control unit is connected to a non-inverting input terminal of the first operational amplifier AMP, a second end of the n +1 th short-circuit control unit is connected to an inverting output terminal of the first operational amplifier AMP, a control end of the n +1 th short-circuit control unit is connected to an output terminal of an n +1 th temperature detection comparing unit in the temperature detection module, and a signal received by the control end of the n +1 th short-circuit control unit determines whether the non-inverting input terminal of the first operational amplifier AMP is short-circuited with the inverting output terminal of the first operational amplifier AMP through the n +1 th short-circuit control unit;
when the temperature is not raised, the (n +1) th short-circuit control unit in the gain logic unit is in an off state (namely, is not in short circuit), and when the temperature is raised to a preset upper limit value, under the control of the (n +1) th temperature detection comparison unit in the temperature detection module, the (n +1) th short-circuit control unit short-circuits the non-inverting input end of the first operational amplifier AMP and the inverting output end of the first operational amplifier AMP so as to close the gain of the circuit.
In this embodiment, the gain adjustment module further includes n control signal conversion units, configured to perform signal conversion and generate a control signal;
the output end of the kth temperature detection comparison unit is simultaneously connected with the control end of the kth short-circuit control unit in the first gain logic group and the second gain logic group through the corresponding kth control signal conversion unit in the n control signal conversion units;
each control signal conversion unit comprises an OR gate;
the first input end of an OR gate in the kth control signal conversion unit is connected with an external control end, the second input end of the OR gate in the kth control signal conversion unit is connected with the output end of the kth temperature detection comparison unit, and the output end of the OR gate in the kth control signal conversion unit is simultaneously connected with the control end of the kth short-circuit control unit in the first gain logic group and the second gain logic group;
wherein, the kth temperature detection comparing unit is any one of the n +1 temperature detection comparing units except the n +1 temperature detection comparing unit.
In this embodiment, each of the short-circuit control units connected to the third resistor string is formed by a transmission gate formed by connecting a first PMOS transistor and a first NMOS transistor in parallel, and a control end of the short-circuit control unit is formed by a gate of the first PMOS transistor and a gate of the first NMOS transistor respectively; the structure can reduce the influence of channel effect;
each control signal conversion unit also comprises a second inverter;
one end of the output end of the OR gate in the kth control signal conversion unit is led out and is directly connected with the grid electrode of the first PMOS tube in the kth short-circuit control unit; one end of the output end of the OR gate in the kth control signal conversion unit is also led out and connected with the grid electrode of the first NMOS tube in the kth short-circuit control unit through the second phase inverter in the control signal conversion unit.
In other embodiments, a single controllable switch can be adopted to form a short-circuit control unit, and the required function can be realized through one control signal; each short-circuit control unit in the embodiment is composed of a transmission gate formed by connecting a first PMOS tube and a first NMOS tube in parallel, and the control ends of the first PMOS tube and the first NMOS tube are respectively controlled through two opposite control signals so as to control the on-off of the two tubes.
In this embodiment, the driving unit includes a first comparator COMP1 ', a second comparator COMP 2', and a driving subunit;
the non-inverting input terminal of the first comparator COMP1 'forms the first input terminal of the driving unit, the non-inverting input terminal of the second comparator COMP 2' forms the second input terminal of the driving unit, and the inverting input terminal of the first comparator COMP1 'and the inverting input terminal of the second comparator COMP 2' together form the third input terminal of the driving unit;
the output end of the first comparator COMP1 'is connected to the first input end of the driving subunit, the output end of the second comparator COMP 2' is connected to the second input end of the driving subunit, the first output end of the driving subunit constitutes the first output end of the driving unit, and the second output end of the driving subunit constitutes the second output end of the driving unit.
In this embodiment, the circuit structure further includes a reference module, and the reference module includes a first transistor Q0, a second transistor Q1, a second operational amplifier, a first field effect transistor M0, a second field effect transistor M1, a third field effect transistor M2, a fourth field effect transistor M3, a sixth resistor R' and a seventh resistor R ";
the base of the first triode Q0, the collector of the first triode Q0, the base of the second triode Q1 and the collector of the second triode Q1 are all grounded;
the emitter of the first triode Q0 is simultaneously connected to the non-inverting input of the second operational amplifier, the drain of the third fet M2 and the first end of the sixth resistor R';
an emitter of the second triode Q1 is connected to a first end of the seventh resistor R ", and a second end of the seventh resistor R" is connected to an inverting input terminal of the second operational amplifier and a drain of the second fet M1;
the output end of the second operational amplifier is simultaneously connected with the grid electrode of the first field effect transistor M0, the grid electrode of the second field effect transistor M1, the grid electrode of the third field effect transistor M2 and the grid electrode of the fourth field effect transistor M3;
the source electrode of the first field effect transistor M0, the source electrode of the second field effect transistor M1, the source electrode of the third field effect transistor M2 and the source electrode of the fourth field effect transistor M3 are all connected with a power supply end VCC;
a second end of the sixth resistor R 'is connected to the drain of the fourth fet M3, and a terminal is led out from the connection between the sixth resistor R' and the fourth fet M3 for outputting the reference voltage VREF;
the area of the first triode is smaller than that of the second triode;
the grid of the first field effect transistor M0 is connected with the drain of the first field effect transistor M0, and one end of the first field effect transistor M0 is led out from the connection of the grid and the drain of the first field effect transistor M0 to output the detection current IREF.
The reference voltage VREF generated by the reference module is a reference voltage with zero temperature drift, and the corresponding detection current IREF is a bias current, which is a detection current varying with temperature, i.e., the reference voltage VREF has no temperature coefficient, and the bias current has a temperature coefficient.
The reference voltage VREF can be calculated by using the following formula:
VBE is voltage between a base stage and an emitter stage of the triode, delta VBE is voltage difference between a base region and an emitter region of the triode, R 'is resistance of the sixth resistor, and R' is resistance of the seventh resistor;
the detection current IREF can be calculated using the following formula:
Δ VBE has a positive temperature, i.e., the detection current IREF.
The working principle of the high-temperature protection circuit structure of the audio power amplifier circuit is further explained as follows:
in this embodiment, since the first resistor string is connected in series between the detection current IREF and the ground, the voltage across the first resistor in the first resistor string closer to the detection current IREF is larger, and the voltage across the first resistor farther from the detection current IREF is smaller, as shown in fig. 2, the voltage across the first resistor R1 in the first resistor string > the voltage across the first resistor R2 > the voltage across the first resistor R3 > … … > the voltage across the first resistor Rn +1 > the voltage across the first resistor Rn +2, that is, the voltage across the voltage collection point a1 > the voltage across the voltage collection point a2 > … … > the voltage across the voltage collection point an > the voltage across the voltage collection point a.
In this embodiment, the third comparators COMP1 to COMP in fig. 2 are comparators functioning as gain adjustment functions, and the third comparators COMP1 to COMP output corresponding temperature detection signals V1, V2, … …, Vn when the detection temperature rises to T1, T2, … …, Tn, respectively; the third comparator COMP is a comparator that performs gain turn-off control, and outputs a corresponding temperature detection signal V (V1 > V2 > … … > Vn > V) when the temperature rises to T; when the circuit is in operation, when the temperature does not rise, assuming that the signals V1, V2, … … and Vn output by each third comparator are all in the first state (i.e. low level), as the temperature of the circuit rises, the signals V1, V2, … … and Vn output by each third comparator sequentially change to the second state (i.e. low level), and in the process, the gain gradually decreases; until the temperature continues to rise to T, the third comparator COMP is triggered, the output signal V is changed from the first state to the second state (i.e. from low level to high level), and the output signal V is transmitted to the short circuit control unit connected to the two ends of the first operational amplifier AMP, so that the circuit power amplifier is turned off.
It is assumed that the low level mentioned in the above is 0V and the high level is 5V. When the temperature rises, the circuit detects n +1 temperatures which are respectively used for triggering the third comparators to change; the first n detected temperatures are used for changing output signals V1, V2, … … and Vn of corresponding third comparators COMP1 to COMPn, so that the gain is adjusted; and the (n +1) th temperature is used for triggering the change of V output by the third comparator COMP to close the circuit efficacy.
In this embodiment, each third comparator is connected to a temperature drop delay recovery unit, which sets a temperature hysteresis for each voltage comparator (i.e. third comparator) for detecting temperature, for the sake of easy understanding, the operation state of the third comparator COMP1 is taken as an example for the following description, when the temperature rises, since the signal V1 output from the third comparator COMP1 changes from low level to high level, under the action of the first inverter and the first controllable switch connected to the third comparator COMP1, the resistance from the node a1 connected in series to the ground increases, the voltage of the node becomes large, and at this time, if the circuit wants to recover the previous power amplifier gain, since the total resistance value R of the resistor connected in series between the detection current IREF and ground increases, the current I becomes smaller, the temperature needs to be lowered to a lower temperature, the temperature hysteresis range can be conveniently adjusted in the circuit by adjusting the resistance at node a11 to ground.
The first resistors R1 to Rn are node resistors providing nodes for the comparator having the gain adjustment function, during actual design, resistors with different resistance values may be used to form each first resistor in the first resistor string to obtain different corresponding temperature rise detection temperatures, the first resistor Rn +1 is a node resistor providing nodes for the comparator having the gain turn-off control, Rn +2 is an intermediate resistor, and the second resistors R11 to R (n +1)1 are hysteresis resistors, and similarly, during actual design, resistors with different resistance values may be used to form each second resistor in the second resistor string to obtain different corresponding temperature fall detection temperatures.
For ease of understanding, the operating states of the respective temperature drop delay recovery units are described below with reference to specific values:
the first inverter and the first controllable switch in each temperature drop delay recovery unit function as:
the temperature detection provides hysteresis x deg.C, and if the temperature rises to 120 deg.C, V1 changes from low to high, then the temperature drops to (120-x) deg.C, and V1 changes from high to low. Similarly, the temperature continues to rise to 130 ℃, V2 begins to go low to high, then the temperature drops to (130-x) degrees c, and so on.
When the detected temperature rises, the output signals of all the third comparators in the temperature detection module are sequentially changed from low level to high level, the temperature rise detection temperature of trigger change is determined by the first resistors R1 to Rn, and different temperature rise detection temperatures are obtained by adjusting the corresponding first resistors R1 to Rn; when the detected temperature is reduced, the output signal of each third comparator is sequentially changed from high level to low level, the temperature reduction detected temperature of the trigger change is determined by the hysteresis resistors R11 to R (n +1)1, and different temperature reduction detected temperatures are obtained by adjusting the corresponding hysteresis resistors R11 to R (n +1) 1. The change in resistance value affects the temperature detection value and the hysteresis amount of the circuit.
The above-mentioned 120 ℃ and 130 ℃ are only one form of embodiment, and the specific values in practical use can be obtained by adjusting the corresponding resistors R1 to Rn, and the hysteresis temperature x can be obtained by adjusting R11 to R (n +1) 1.
When the circuit works, each temperature detection comparison unit respectively compares the voltage on the voltage acquisition point acquired by each temperature detection comparison unit with the reference voltage VREF, and if the detection current IREF rises to a certain value, the voltage acquired on the corresponding voltage acquisition point is larger than the reference voltage VREF, so that the state of the signal output by the temperature detection comparison unit is changed.
For convenience of description, the operation state of the third comparator COMP1 is taken as an example, when the voltage collected by the third comparator COMP1 from the voltage collection point a1 is greater than the reference voltage VREF as the temperature rises, the output state of the third comparator COMP1 changes from low level to high level, that is, v1 changes from low level to high level, so that the short circuit control unit corresponding to the third comparator COMP1 in the gain logic unit in the gain adjustment module is disconnected to allow a signal to pass through the third resistor r1, and the gain is reduced; on the contrary, as the temperature decreases, after the voltage collected by the third comparator COMP1 from the voltage collection point a1 is less than the reference voltage, the output state of the third comparator COMP1 changes from high level to low level, that is, v1 changes from high level to low level, so that the short-circuit control unit in the gain logic unit in the gain adjustment module corresponding to the third comparator COMP1 shorts the resistor r1, so that the signal does not pass through the third resistor r1, and the gain is increased.
The working principle of each temperature detection comparing unit in the temperature detection module is the same, but the voltage collected by each temperature detection comparing unit from the voltage collecting point is different, that is, the triggering condition of each third comparator is different (the temperature rise detection temperature corresponding to each temperature detection comparing unit in fig. 2 is sequentially increased from top to bottom, and the temperature fall detection temperature is sequentially decreased), along with the larger the variation amplitude of the detection current IREF is, the more the third comparators changing the output state are, and the larger the adjustment amount of the gain is; in the temperature rising process, if the output of the third comparator COMP is also converted from a low level to a high level when the temperature rises to a certain value, the short-circuit control unit connected to the two ends of the first operational amplifier AMP is also triggered, so that the gain of the whole circuit is turned off.
In this embodiment, the external control terminal connected to the first input terminal of the or gate in each control signal conversion unit is configured to receive the GAIN of the regulating circuit before the circuit is heated, and the kth control signal conversion unit is configured to perform signal conversion on the signal output by the output terminal of the kth temperature detection comparing unit and the GAIN received from the external control terminal, and generate a corresponding control signal, which is transmitted to the control terminal of the kth short-circuit control unit in the first GAIN logic group and the second GAIN logic group. That is, the GAIN adjustment module obtains the GAIN control signals CTRT1, CTRT2, … … and CTRTn by performing logic calculation on the detected temperature detection signals V1, V2, … … and Vn and the GAIN received from the external control terminal, and the associated truth table is shown in table 1 below, where "0" indicates a low level and "1" indicates a high level:
| GAIN | V1 | V2 | …… | Vn | CTRT1 | CTRT2 | …… | |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| 1 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
| 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
TABLE 1
The calculation formula of the actual gain value in the gain adjustment module in fig. 5 is as follows:
Avfor the gain of the gain adjustment module, Rin is an actual resistance value of a resistor through which the first input signal INP (or the second input signal INN) is transmitted to the first operational amplifier AMP, the value of Rin varies with temperature (i.e., the gain adjustment signal output by the temperature detection module determines the number of transmission gates turned on to adjust the actual value of Rin), the states of the gain control signals CTRT1, CTRT2, … …, CTRTn also vary with temperature, and Rf is a resistance value of the fourth resistor Rf1 (or the fifth resistor Rf 2).
When the temperature gradually rises, the change process of the gain adjusting module can be sequentially referred to the following formula:
……
i.e., the input resistance increases (i.e., Rin increases) after the temperature rises, the gain a of the gain adjustment modulevAnd decreases.
When the temperature is not raised, V1, V2, … …, Vn are low level, and the circuit GAIN depends on the level of the external control terminal of the GAIN of the regulating circuit before the access circuit is raised in temperature. For example, the circuit has two levels of selectable gains, namely, when the external control end is at a low level, the gain is 26 dB; when the level of the external control terminal is high, the gain is 20 dB. When the temperature rises, the temperature detection signals V1, V2, … … and Vn change from low level to high level, and the gain range is 20dB to 26 dB. And when the temperature is detected to rise, the gain is reduced by 6/n (dB), wherein n is the number of third comparators for detecting COMP 1-COMPn in the circuit. The circuit can be provided with a plurality of external control ends for receiving the GAIN GAIN, the circuit can obtain different stepping power amplifier GAINs by adjusting the number n of the third comparators, and the corresponding GAIN adjusting module is arranged, so that the continuous adjustment of the GAINs in the over-temperature process can be obtained.
The high-temperature protection circuit structure of the audio power amplifier circuit in the embodiment provides a high-temperature processing method of the audio power amplifier circuit, when the temperature rises, the power amplifier circuit continues to work, the signal distortion rate is unchanged, after the temperature continues to rise, the circuit can still be turned off, and the circuit is protected from being burnt out, so that the high-temperature protection circuit structure has the following advantages:
1) the temperature detection module is integrated in the chip, and when the temperature rises, the method of outputting a corresponding gain adjustment signal through the temperature detection module to reduce the gain of the power amplifier is adopted, so that the sound is continuously amplified, the auditory experience is improved, and the circuit loss caused by switching due to temperature change is avoided;
2) the distortion rate of the signal remains unchanged;
3) after the temperature continues to rise, the protection signal for turning off the power amplifier can still be triggered, and the protection circuit is prevented from being burnt out;
4) the temperature hysteresis function is set, and when the temperature is recovered and reaches the safe circuit temperature, the circuit can return to the original state, so that the influence on the hearing feeling caused by the repeated change of signals is avoided;
5) and a plurality of temperature detection and comparison units are arranged to realize multi-gear gain adjustment in a temperature range.
By adopting the circuit structure in the embodiment, the signals are continuously amplified by changing the gain of the power amplifier at different temperatures through temperature detection when the circuit works for a long time or the temperature rises, the phenomenon that the power amplifier is turned off under temperature protection due to temperature rise is avoided, sound break occurs, the distortion degree of the input audio signals is not changed by changing the gain of the power amplifier, and the hearing experience is improved. The method is simple and realizes continuous processing of the over-temperature signal. And when the temperature recovers, the gain is reversible.
By adopting the high-temperature protection circuit structure of the audio power amplifier circuit, when the audio power amplifier circuit works for a long time or the temperature rises, the gain adjusting signal which changes along with the temperature change is output to the gain adjusting module through the temperature detecting module, a basis is provided for the gain adjusting module to adjust the gain, the gain of the power amplifier at different temperatures is changed, the auditory experience is improved, and the problems of circuit loss caused by switch switching and sound interruption of the temperature protection turn-off power amplifier caused by temperature change are avoided; after the temperature continues to rise, the protection signal for turning off the power amplifier can still be triggered, and the protection circuit is burnt out; the circuit has set up several temperature detection comparing element, has realized that the gain of many grades is adjustable, carries out continuous processing to the signal when overtemperature, and simultaneously, circuit structure still includes the temperature decline delay recovery unit that quantity and temperature detection comparing element match, and when the temperature recovery back, the circuit safety can get back to original condition, and this circuit structure effectively makes the distortion rate of the audio signal of input keep unchangeable, has promoted the sense of hearing and has experienced.
In this specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
Claims (10)
1. The high-temperature protection circuit structure of the audio power amplifier circuit is characterized by comprising the following components:
the temperature detection module is used for outputting a corresponding gain adjustment signal along with the change of the temperature;
the gain adjusting module is connected with the temperature detecting module and is used for adjusting the gain according to the gain adjusting signal;
the temperature detection module comprises a first resistor string and n +1 temperature detection comparison units, the first resistor string comprises n +2 first resistors which are connected in series, a node between every two adjacent first resistors in the first resistor string forms a voltage acquisition point, the first resistor string is connected between detection current and ground in series, and the detection current changes along with the change of the temperature;
the first input end of the kth temperature detection comparison unit is correspondingly connected between the kth first resistor and the (k +1) th first resistor in the first resistor string, the second input end of the kth temperature detection comparison unit is connected with a reference voltage, the kth temperature detection comparison unit is used for comparing the voltage at the kth voltage acquisition point in the first resistor string with the reference voltage, and the output end of the kth temperature detection comparison unit is connected with a gain adjustment module;
the kth temperature detection comparison unit is any one of the n +1 temperature detection comparison units, the kth first resistor is any one of n +2 first resistors connected in series in the first resistor string, the kth voltage acquisition point is a voltage acquisition point formed by a node between the kth first resistor and the kth +1 first resistor in the first resistor string, and n is larger than or equal to 2.
2. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 1, wherein the temperature detection module further comprises n +1 temperature drop delay recovery units and a second resistor string, the first resistor string is connected in series with the second resistor string and then grounded, and the second resistor string comprises n +1 second resistors connected in series;
the first end of the kth temperature drop delay recovery unit is connected with one end, close to the first resistor, of the kth second resistor, the second end of the kth temperature drop delay recovery unit is grounded, and the control end of the kth temperature drop delay recovery unit is connected with the output end of the kth temperature detection comparison unit;
and the control end of the kth temperature drop delay recovery unit receives a signal to determine whether one end of the kth second resistor close to the first resistor is connected with the ground or not.
3. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 2, wherein each of the temperature drop delay recovery units comprises a first inverter and a first controllable switch, an input terminal of the first inverter forms a control terminal of the temperature drop delay recovery unit, an output terminal of the first inverter is connected to an input terminal of the first controllable switch, a first terminal of the first controllable switch forms a first terminal of the temperature drop delay recovery unit, and a second terminal of the first controllable switch forms a second terminal of the temperature drop delay recovery unit.
4. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 1, wherein the gain adjustment module comprises a gain logic unit and a driving unit, the gain logic unit comprises a first operational amplifier, a fourth resistor, a fifth resistor, and a first gain logic group and a second gain logic group with the same structure;
the first gain logic group and the second gain logic group respectively comprise n short-circuit control units and a third resistor string, and the third resistor string comprises n +2 third resistors connected in series;
the first end of the kth short-circuit control unit is connected with the second end of the kth third resistor in the third resistor string, the second end of the kth short-circuit control unit is connected with the first end of the (n + 2) th third resistor in the third resistor string, the control end of the kth short-circuit control unit is connected with the output end of the kth temperature detection comparison unit, and whether the second end of the kth third resistor is short-circuited with the first end of the (n + 2) th third resistor in the third resistor string through the corresponding kth short-circuit control unit is determined by a signal received by the control end of the kth short-circuit control unit, wherein the kth third resistor is any one of the third resistors in the third resistor string except for the n +2 th third resistor;
a first end of a first one of the third resistors in a third resistor string in the first gain logic set is connected with a first input signal, and a second end of an n +2 th one of the third resistors in the third resistor string in the first gain logic set is connected with a non-inverting input end of the first operational amplifier; a first end of a first one of the third resistors in a third resistor string in the second gain logic group is connected with a second input signal, and a second end of an n +2 th one of the third resistors in the third resistor string in the second gain logic group is connected with an inverting input end of the first operational amplifier;
a first end of the fourth resistor is connected with a non-inverting input end of the first operational amplifier, a second end of the fourth resistor is connected with a first output end of the driving unit, and an inverting output end of the first operational amplifier is connected with the first input end of the driving unit; a first end of the fifth resistor is connected with the inverting input end of the first operational amplifier, a second end of the fifth resistor is connected with the second output end of the driving unit, and the non-inverting output end of the first operational amplifier is connected with the second input end of the driving unit; and the third input end of the driving unit is connected with a pulse signal.
5. The high temperature protection circuit structure of audio power amplifier circuit of claim 4, the gain logic unit also comprises an n +1 th short-circuit control unit, the first end of the n +1 th short-circuit control unit is connected with the non-inverting input end of the first operational amplifier, the second end of the (n +1) th short-circuit control unit is connected with the inverted output end of the first operational amplifier, the control end of the (n +1) th short-circuit control unit is connected with the output end of the (n +1) th temperature detection comparison unit in the temperature detection module, and whether the non-inverting input end of the first operational amplifier is in short circuit with the inverting output end of the first operational amplifier through the (n +1) th short-circuit control unit is determined by a signal received by the control end of the (n +1) th short-circuit control unit.
6. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 4, wherein the gain adjustment module further comprises n control signal conversion units for performing signal conversion and generating control signals;
the output end of the kth temperature detection comparison unit is simultaneously connected with the control end of the kth short-circuit control unit in the first gain logic group and the second gain logic group through the corresponding kth control signal conversion unit in the n control signal conversion units;
each control signal conversion unit comprises an OR gate;
the first input end of an OR gate in the kth control signal conversion unit is connected with an external control end, the second input end of the OR gate in the kth control signal conversion unit is connected with the output end of the kth temperature detection comparison unit, and the output end of the OR gate in the kth control signal conversion unit is simultaneously connected with the control end of the kth short-circuit control unit in the first gain logic group and the second gain logic group;
wherein, the kth temperature detection comparing unit is any one of the n +1 temperature detection comparing units except the n +1 temperature detection comparing unit.
7. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 6, wherein each of the short-circuit control units is formed by a transmission gate formed by connecting a first PMOS transistor and a first NMOS transistor in parallel, and a control end of the short-circuit control unit is formed by a gate of the first PMOS transistor and a gate of the first NMOS transistor respectively;
each control signal conversion unit also comprises a second inverter;
one end of the output end of the OR gate in the kth control signal conversion unit is led out and is directly connected with the grid electrode of the first PMOS tube in the kth short-circuit control unit; one end of the output end of the OR gate in the kth control signal conversion unit is also led out and connected with the grid electrode of the first NMOS tube in the kth short-circuit control unit through the second phase inverter in the control signal conversion unit.
8. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 4, wherein the driving unit comprises a first comparator, a second comparator and a driving subunit;
the non-inverting input terminal of the first comparator forms the first input terminal of the driving unit, the non-inverting input terminal of the second comparator forms the second input terminal of the driving unit, and the inverting input terminal of the first comparator and the inverting input terminal of the second comparator together form the third input terminal of the driving unit;
the output end of the first comparator is connected with the first input end of the driving subunit, the output end of the second comparator is connected with the second input end of the driving subunit, the first output end of the driving subunit forms the first output end of the driving unit, and the second output end of the driving subunit forms the second output end of the driving unit.
9. The high temperature protection circuit structure of audio power amplifier circuit according to claim 1, wherein each of said temperature detection comparing units comprises a third comparator, a non-inverting input terminal of each of said third comparators constitutes a first input terminal of the temperature detection comparing unit, an inverting input terminal of each of said third comparators constitutes a second input terminal of the temperature detection comparing unit, and an output terminal of each of said third comparators constitutes an output terminal of the temperature detection comparing unit.
10. The high-temperature protection circuit structure of an audio power amplifier circuit according to claim 1, wherein the circuit structure further comprises a reference module, and the reference module comprises a first triode, a second operational amplifier, a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, a fourth field-effect transistor, a sixth resistor and a seventh resistor;
the base electrode of the first triode, the collector electrode of the first triode, the base electrode of the second triode and the collector electrode of the second triode are all grounded;
the emitter of the first triode is simultaneously connected with the non-inverting input end of the second operational amplifier, the drain of the third field effect transistor and the first end of the sixth resistor;
an emitter of the second triode is connected with a first end of the seventh resistor, and a second end of the seventh resistor is connected with an inverting input end of the second operational amplifier and a drain electrode of the second field effect transistor at the same time;
the output end of the second operational amplifier is simultaneously connected with the grid electrode of the first field effect transistor, the grid electrode of the second field effect transistor, the grid electrode of the third field effect transistor and the grid electrode of the fourth field effect transistor;
the source electrode of the first field effect transistor, the source electrode of the second field effect transistor, the source electrode of the third field effect transistor and the source electrode of the fourth field effect transistor are all connected with a power supply end;
the area of the first triode is smaller than that of the second triode;
the second end of the sixth resistor is connected with the drain electrode of the fourth field effect transistor, and one end of the sixth resistor is led out from the connection position of the sixth resistor and the fourth field effect transistor and used for outputting the reference voltage;
the grid electrode of the first field effect transistor is connected with the drain electrode of the first field effect transistor, and one end of the grid electrode of the first field effect transistor is led out from the connection position of the grid electrode of the first field effect transistor and the drain electrode of the first field effect transistor and used for outputting the detection current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911408836.4A CN113126668B (en) | 2019-12-31 | 2019-12-31 | High-temperature protection circuit structure of audio power amplifier circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911408836.4A CN113126668B (en) | 2019-12-31 | 2019-12-31 | High-temperature protection circuit structure of audio power amplifier circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113126668A true CN113126668A (en) | 2021-07-16 |
| CN113126668B CN113126668B (en) | 2021-11-26 |
Family
ID=76770034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911408836.4A Active CN113126668B (en) | 2019-12-31 | 2019-12-31 | High-temperature protection circuit structure of audio power amplifier circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113126668B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710791A (en) * | 2009-07-27 | 2010-05-19 | 张仁增 | High-frequency transform type power supply and audio power amplification processing circuit with same |
| CN101930247A (en) * | 2009-06-25 | 2010-12-29 | 上海华虹Nec电子有限公司 | Voltage reference circuit with automatic protection |
| CN101959100A (en) * | 2010-05-25 | 2011-01-26 | 瑞声声学科技(深圳)有限公司 | Protective circuit for voice frequency circuit system and voice frequency circuit system using same |
| CN201887652U (en) * | 2010-11-16 | 2011-06-29 | 中国电子科技集团公司第五十八研究所 | Adjustable overheat protection circuit in switch power supply |
| CN102142818A (en) * | 2011-01-21 | 2011-08-03 | 上海艾为电子技术有限公司 | Class-AB amplifier and over-temperature protection circuit thereof |
| CN108092630A (en) * | 2016-11-22 | 2018-05-29 | 无锡华润矽科微电子有限公司 | Power amplifier and its load supplying circuit with overcurrent protection structure |
| CN208369534U (en) * | 2018-01-29 | 2019-01-11 | 广州市浪源音响器材有限公司 | A kind of active audio frequency power amplifier with thermostat |
-
2019
- 2019-12-31 CN CN201911408836.4A patent/CN113126668B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101930247A (en) * | 2009-06-25 | 2010-12-29 | 上海华虹Nec电子有限公司 | Voltage reference circuit with automatic protection |
| CN101710791A (en) * | 2009-07-27 | 2010-05-19 | 张仁增 | High-frequency transform type power supply and audio power amplification processing circuit with same |
| CN101959100A (en) * | 2010-05-25 | 2011-01-26 | 瑞声声学科技(深圳)有限公司 | Protective circuit for voice frequency circuit system and voice frequency circuit system using same |
| CN201887652U (en) * | 2010-11-16 | 2011-06-29 | 中国电子科技集团公司第五十八研究所 | Adjustable overheat protection circuit in switch power supply |
| CN102142818A (en) * | 2011-01-21 | 2011-08-03 | 上海艾为电子技术有限公司 | Class-AB amplifier and over-temperature protection circuit thereof |
| CN108092630A (en) * | 2016-11-22 | 2018-05-29 | 无锡华润矽科微电子有限公司 | Power amplifier and its load supplying circuit with overcurrent protection structure |
| CN208369534U (en) * | 2018-01-29 | 2019-01-11 | 广州市浪源音响器材有限公司 | A kind of active audio frequency power amplifier with thermostat |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113126668B (en) | 2021-11-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11082010B2 (en) | Systems and methods for TIA base current detection and compensation | |
| JP5563154B2 (en) | Differential comparison circuit with wide common mode input range | |
| JP4896547B2 (en) | Transimpedance amplifier with signal amplification circuit for adjusting power signal | |
| CN108462476B (en) | Power amplifier and power control method thereof | |
| US9154090B2 (en) | Integrated start-up bias boost for dynamic error vector magnitude enhancement | |
| CN104460811A (en) | Reference voltage temperature coefficient calibration circuit and method | |
| CN107562111B (en) | DC stabilized power supply and voltage regulation method | |
| EP0587965B1 (en) | Differential transconductance stage, dynamically controlled by the input signal's amplitude | |
| WO2019227822A1 (en) | Operational amplification circuit and method for overcurrent protection thereof | |
| CN102710109B (en) | Current limiting circuit for DC/DC (Direct Current/Direct Current) converter | |
| CN106066419A (en) | Current detection circuit | |
| CN112148054A (en) | Feedback network circuit applied to LDO (low dropout regulator) with ultra-low voltage input and multi-voltage output | |
| CN113126668B (en) | High-temperature protection circuit structure of audio power amplifier circuit | |
| CN101485083A (en) | Variable gain amplifier having linear-in-dB gain characteristic | |
| CN110132444B (en) | Temperature detection circuit | |
| CN204347680U (en) | Reference voltage temperature coefficient calibration circuit | |
| CN113541657A (en) | Power switch overcurrent detection circuit and current detection circuit | |
| CN104617899A (en) | differential amplifier and electronic device | |
| US9654074B2 (en) | Variable gain amplifier circuit, controller of main amplifier and associated control method | |
| WO2023134667A1 (en) | Adjustable driving unit, driving assembly, power supply conversion apparatus, and output control method | |
| US20230327659A1 (en) | Driving apparatus and driving method | |
| CN115967359B (en) | Temperature compensation circuit of radio frequency amplifier and grid voltage adjusting method of radio frequency amplifier | |
| CN112198925B (en) | Current network trimming circuit applied to multi-voltage output low-noise LDO (Low dropout regulator) | |
| JP5678829B2 (en) | Output circuit | |
| US8195107B2 (en) | Signal transmission system and signal transmission method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |