CN102468808A - Thermal protection circuit and method of audio power amplification circuit - Google Patents
Thermal protection circuit and method of audio power amplification circuit Download PDFInfo
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- CN102468808A CN102468808A CN2010105343777A CN201010534377A CN102468808A CN 102468808 A CN102468808 A CN 102468808A CN 2010105343777 A CN2010105343777 A CN 2010105343777A CN 201010534377 A CN201010534377 A CN 201010534377A CN 102468808 A CN102468808 A CN 102468808A
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Abstract
The invention discloses a thermal protection circuit and a thermal protection method of an audio power amplification circuit. The audio power amplification circuit comprises a preamplifier, an output amplifier, a temperature detector and a gain adjustment circuit, wherein the preamplifier is used for receiving and amplifying an audio signal to generate an amplified audio signal; the output amplifier is used for receiving the amplified audio signal and outputting the amplified audio signal to a rear load; the temperature detector is used for detecting the temperature of the output amplifier to output a temperature signal; and the gain adjustment circuit is used for adjusting the magnitude of the amplified audio signal output by the preamplifier according to the magnitude of the temperature signal.
Description
Technical field
The present invention system is about a kind of temperature protection circuit, and further, the present invention system is about a kind of thermal protection circuit and method of audio power amplifying circuit.
Background technology
The purpose of audio frequency amplifier is on sonorific output element, rebuilds the audio signal of input.Audiorange is about 20Hz～20kHz, so amplifier must have good frequency response in this scope.According to the difference of using; Watt level is widely different; From the milliwatt level of earphone to TV or computer audio frequency several watts; Arrive " mini " family's stereophonic and automobile audio again tens watts,, big to the sound requirement that can satisfy whole cinema or auditorium up to more than hundreds of watts of more powerful family expenses and commercial sound system.
Fig. 1 is the circuit block diagram of the audio frequency amplifier of prior art.Please refer to Fig. 1, audio frequency amplifier comprises pre-amplifier 101, output stage amplifier 102 and a feedback circuit 103.Pre-amplifier 101 is responsible for the small-signal Vin of input is amplified, the input signal Va after amplifying with output.Because the input signal Va through after the voltage amplification still is not enough to directly promote loudspeaker, output stage amplifier 102 mainly is the input signal Va after amplifying to be made electric current amplify to obtain enough electric current promotion loudspeaker 104.103 of feedback circuits are to utilize degenerative principle, improve the stability of integrated circuit, and improve frequency response.
Because the electric current that output stage amplifier 102 flows through is bigger, power consumption is also bigger, can be coupled with fin usually.Yet therefore fin might not usually have output stage amplifier 102 overheated situations of burning with the complete dissipation of the heat that output stage amplifier 102 is distributed.For head it off, the someone proposes to be provided with temperature detection mechanism, and the temperature of monitoring audio frequency amplifier when temperature during greater than certain threshold, is just closed audio frequency amplifier and burnt to avoid audio frequency amplifier.Yet, so, can let the user's acoustically have a uncomfortable feeling.
Summary of the invention
A purpose of the present invention is to provide a kind of thermal protection circuit of audio amplifier circuit, is burnt in order to avoid audio amplifier circuit.
Another purpose of the present invention is to provide a kind of audio amplifier circuit, in order to do not avoid the use of simultaneously the person acoustically sticky feeling and the protection audio amplifier circuit running normal.
In view of this, the present invention provides a kind of audio power amplifying circuit, and this audio power amplifying circuit comprises pre-amplifier, output stage amplifier, Temperature Detector and gain adjustment circuit.Pre-amplifier is in order to receiving an audio signal, and amplifies, to produce a audio signal after amplifying.Output stage amplifier is in order to receiving the audio signal after this amplification, and exports to the load of back level.Temperature Detector is in order to the temperature of detecting output stage amplifier, to export a temperature signal.Gain adjustment circuit is in order to the size according to temperature signal, the size of the audio signal after the amplification that the adjustment pre-amplifier is exported.
According to the said audio power amplifying circuit of preferred embodiment of the present invention, above-mentioned pre-amplifier comprises that one is differential right.In addition; In one embodiment, above-mentioned gain adjustment circuit comprises the adjustable current source, this adjustable current source couple above-mentioned differential to and Temperature Detector; In order to the temperature signal of being exported according to the said temperature detector, adjustment is supplied to an above-mentioned differential right direct current bias current.
In another embodiment; Above-mentioned gain adjustment circuit comprises an attenuator; This attenuator is coupled between pre-amplifier and the output stage amplifier; Audio signal after the amplification that the reception pre-amplifier is exported is according to the temperature that Temperature Detector is exported, the size of the audio signal after adjustment is amplified.In another embodiment, above-mentioned attenuator comprises a transistor and a resistance.Above-mentioned transistor comprises a grid, one first source-drain electrode and one second source-drain electrode, and its grid receives this temperature signal, and its first source-drain electrode couples this pre-amplifier, and receives the audio signal after this amplification.Above-mentioned resistance comprises one first end and one second end, and its first end couples this transistorized first source-drain electrode, and its second end couples and connects voltage altogether.
According to the said audio power amplifying circuit of preferred embodiment of the present invention, above-mentioned attenuator comprises N transmission lock and N+1 resistance.Each transmission lock comprises an input, an output respectively, and each output couples this output stage amplifier.Each resistance comprises one first end and one second end respectively; First end of first resistance couples this pre-amplifier; And receive the audio signal after this amplification; Second end of N+1 resistance couples and connects voltage altogether, and second end of K resistance couples first end of K+1 resistance, and second end of K resistance couples the input of K transmission lock.Wherein, according to the size of this temperature signal, the conducting that determines those N transmission locks with end, wherein, K and N are natural number, 0＜K≤N.
In another embodiment, above-mentioned attenuator comprises an amplifier, one first resistance, N+1 second resistance and N transmission lock.Amplifier comprises a first input end, one second input and an output.First resistance comprises one first end and one second end, and its first end couples this pre-amplifier, and receives the audio signal after this amplification, and its second end couples the first input end of this amplifier.Each second resistance comprises one first end and one second end respectively, and first end of each second resistance couples the first input end of this amplifier, and second end of first second resistance couples the output of this amplifier.N transmission lock, each transmission lock comprises an input and an output respectively, and the input of K transmission lock couples second end of K+1 second resistance, and the output of each transmission lock couples the output of this amplifier.According to the size of this temperature signal, the conducting that determines those N transmission locks with end, wherein, K and N are natural number, 0＜K≤N.
According to the said audio power amplifying circuit of preferred embodiment of the present invention, the said temperature detector comprises a thermocouple and an amplifier.Above-mentioned thermocouple comprises one first metal wire and one second metal wire, and wherein first end of this first metal wire connects first end of this second metal wire, the wherein first end in contact output stage amplifier of this first metal wire.Above-mentioned amplifier couples second end of this first metal wire and this second metal wire, to export a temperature signal.
The present invention provides a kind of integrated audio power amplifying circuit in addition, and this integrated audio power amplifying circuit comprises pre-amplifier, output stage amplifier, Temperature Detector and gain adjustment circuit.Pre-amplifier is in order to receiving an audio signal, and amplifies, to produce a audio signal after amplifying.Output stage amplifier is in order to receiving the audio signal after this amplification, and exports to the load of back level.Temperature Detector is in order to the temperature of detecting output stage amplifier, to export a temperature signal.Gain adjustment circuit is in order to the size according to temperature signal; The size of the audio signal after the amplification that the adjustment pre-amplifier is exported, wherein above-mentioned pre-amplifier, above-mentioned output stage amplifier, said temperature detector and above-mentioned gain adjustment circuit are integrated in the same integrated circuit.
According to the said integrated audio power amplifying circuit of preferred embodiment of the present invention, the said temperature detector comprises a diode, a reference voltage generator and an amplifier.Above-mentioned diode comprises an anode and a negative electrode, and anode couples a bias voltage, and negative electrode couples and connects voltage altogether, and wherein diode arrangement is near the pyrotoxin of integrated audio power amplifying circuit.Above-mentioned reference voltage generator is in order to produce a reference voltage.Above-mentioned amplifier comprises a first input end, one second input and an output; Its first input end couples the anode of this diode; Its second input couples this reference voltage generator, and to receive this reference voltage, its output is in order to export a temperature signal.In a further embodiment, above-mentioned reference voltage generator comprises a bandgap reference circuit.
The present invention provides a kind of heat radiation protection method of audio amplifier circuit in addition, and the method comprises the following steps: that (a) detects a temperature level of the pyrotoxin of audio amplifier circuit; (b) judge that whether temperature level is greater than a temperature threshold; (c) when temperature level less than the temperature threshold, get back to step (b); And (d) when temperature level greater than the temperature threshold, according to temperature level, the size of output signal of adjustment audio amplifier circuit, wherein, temperature level is high more, the output signal of audio amplifier circuit big or small controlled more little.
The present invention's spirit is to be temperature protection is integrated gain adjustment mechanism, as long as temperature is higher than preset threshold value, just along with the height of temperature, progressively reduces gain.So, can avoid sound played to interrupt, that also reduces the user acoustically has a uncomfortable feeling.
State with other purposes for letting on the present invention, feature and advantage can be more obviously understandable, hereinafter is special lifts preferred embodiment, and cooperates appended graphicly, elaborates as follows.
Description of drawings
Fig. 1 is the circuit block diagram of the audio frequency amplifier of prior art;
Fig. 2 is the flow chart of steps of the indoor environment parameter adjusting method of first embodiment of the invention;
Build the circuit diagram of the audio frequency amplifier of thermal protection circuit in Fig. 3 second embodiment of the invention;
Build the circuit block diagram of the audio frequency amplifier of thermal protection circuit in Fig. 4 third embodiment of the invention;
Fig. 5 then builds the circuit diagram of attenuator 404 of the audio frequency amplifier of thermal protection circuit in the fourth embodiment of the invention;
Fig. 6 then builds another circuit diagram of attenuator 404 of the audio frequency amplifier of thermal protection circuit in the fifth embodiment of the invention;
Fig. 7 then builds another circuit diagram of attenuator 404 of the audio frequency amplifier of thermal protection circuit in the sixth embodiment of the invention;
Fig. 8 is the circuit diagram of the integrated audio power amplifying circuit of seventh embodiment of the invention;
Fig. 9 is the flow chart of heat radiation protection method of the audio amplifier circuit of eighth embodiment of the invention.
The main element symbol description:
101,201: pre-amplifier
102,202: output stage amplifier
103: feedback circuit
Vin: input signal, audio signal
Va: the audio signal after the input signal after the amplification, the amplification
104: loudspeaker
203: Temperature Detector
204,404: gain adjustment circuit
301: differential right
302: the adjustable current source
I301: electric current
205: loudspeaker
501: transistor
502, R801: resistance
Vc: the voltage after being attenuated
A601: amplifier
T601: the first transistor
T602: transistor seconds
T603: the 3rd transistor
R601: first resistance
R601: second resistance
R603: the 3rd resistance
R604: the 4th resistance
R605: the 5th resistance
R606: the 6th resistance
TC: temperature control signals
T701: the first transmission lock
T702: the second transmission lock
T703: the 3rd transmission lock
R701: first resistance
R702: second resistance
R703: the 3rd resistance
R704: the 4th resistance
801: diode
802: amplifier
803: reference voltage generator
VTC: temperature signal
VREF: reference voltage
S901～S904: each step of the embodiment of the invention
Embodiment
First embodiment
Build the circuit block diagram of the audio frequency amplifier of thermal protection circuit in Fig. 2 first embodiment of the invention.Please refer to Fig. 2, this audio frequency amplifier comprises pre-amplifier 201, output stage amplifier 202, Temperature Detector 203 and gain adjustment circuit 204.Pre-amplifier 201 is in order to receiving an audio signal Vin, and amplifies, to produce an audio signal Va after amplifying.Audio signal Va after output stage amplifier 202 is amplified in order to reception, and the load 205 (generally being loudspeaker) of exporting to the back level.Temperature Detector 203 is in order to the temperature of detecting output stage amplifier 202, to export a temperature signal.Because output stage amplifier 203 is to be used to promote load, the power of consumption is relatively large, is the main thermal source of audio frequency amplifier therefore.Gain adjustment circuit 204 is adjusted the gain of pre-amplifier 201 in order to the size according to temperature signal.
When temperature is high more, the gain of pre-amplifier 201 is controlled more little, and the electric current that output stage amplifier 202 is exported to load 205 is more little, the sound that the user the heard sound that also can diminish.Because the size sound of sound is to diminish gradually along with the rising of temperature, rather than moment closes.When temperature reduces, gain and can heighten again, it is big that sound also can become gradually.Therefore sound can not closed the person's of avoiding the use of sticky feeling acoustically moment.
In general, can be considered to be automatic gain adjustment (Auto Gain Control) circuit like above-mentioned gain adjustment circuit 204 and Temperature Detector 203.Automatic gain adjustment circuit can be divided into gain controlled amplifying circuit (being the gain adjustment circuit 204 of this case) and control signal forms circuit (being the Temperature Detector 203 of this case) two parts.Following examples describe of the present invention two big circuit respectively.
Second embodiment
Build the circuit diagram of the audio frequency amplifier of thermal protection circuit in Fig. 3 second embodiment of the invention.Please refer to Fig. 3, this embodiment be first embodiment than detailed circuit, wherein, the part of pre-amplifier 201 only show differential to 301 the input part, gain adjustment circuit is then given an example with an adjustable current source 302.In this embodiment, adjustable current source 302 is to implement (N-MOSFET) by N type metal oxide semiconductor field-effect transistor.The circuit diagram of embodiment can be known thus, because the gain of pre-amplifier is to be determined by differential right mutual conductance (gm), as long as adjusted electric current I 301, just can adjust mutual conductance (gm), has further just adjusted the gain of integrated circuit.Therefore, in this embodiment, when temperature raises, along with the voltage Vb of variations in temperature will descend, electric current I 301 also can and then descend, and the gain of pre-amplifier 201 also just and then descends.
The 3rd embodiment
Build the circuit block diagram of the audio frequency amplifier of thermal protection circuit in Fig. 4 third embodiment of the invention.Please refer to Fig. 4, comparatively different with Fig. 2 is that the gain adjustment circuit 404 of this embodiment is to be coupled between pre-amplifier 201 and the output stage amplifier 202, is the form design with attenuator 404.This kind design mainly is to be used for decaying the size of the signal Va that pre-amplifier 201 exported.When temperature was too high, the Va signal just can be dwindled, and output stage amplifier 202 just can drive loudspeaker 205 with less current.Because drive current is less, temperature just can descend thereupon.
The 4th embodiment
Fig. 5 then builds the circuit diagram of attenuator 404 of the audio frequency amplifier of thermal protection circuit in the fourth embodiment of the invention.Please refer to Fig. 5, this attenuator 404 is to be made up of a transistor 501 and 502 of resistance.When temperature rose, the signal Vb of Temperature Detector 203 outputs can diminish.Because transistor 501 quite is a voltage-controlled resistance, Vb diminishes then voltage-controlled resistance 501 changes greatly, so the Va signal is attenuated into Vc by transistor 501 with the dividing potential drop of resistance 502.
The 5th embodiment
Fig. 6 then builds another circuit diagram of attenuator 404 of the audio frequency amplifier of thermal protection circuit in the fifth embodiment of the invention.Please refer to Fig. 6, this attenuator 404 is to be made up of an amplifier A601, the first transistor T601, transistor seconds T602, the 3rd transistor T 603 and first resistance R 601, second resistance R 602, the 3rd resistance R 603, the 4th resistance R 604, the 5th resistance R 605 and 606 of the 6th resistance R.In this embodiment, the function of the first transistor T601, transistor seconds T602 and the 3rd transistor T 603 is as switch.Temperature Detector 203 be in this embodiment control the first transistor T601, transistor seconds T602 and the 3rd transistor T 603 with temperature control signals TC conducting whether.Affiliated technical field has common knowledge the knowledgeable and should know; On the actual circuit design; Temperature Detector 203 can be coupled to the grid of the first transistor T601, transistor seconds T602 and the 3rd transistor T 603 respectively, and in this embodiment, the above-mentioned relation that couples is not shown.
It for example is the kenel of numerical digit that the temperature control signals TC that Temperature Detector 203 is exported can be designed as.When temperature rise high more, multiple transistor T601, T602, T603 are switched on more in Temperature Detector 203 controls.Because the gain of the attenuator 404 of present embodiment can be similar to as follows
Wherein, REQ is the equivalent resistance that the first transistor T601, transistor seconds T602, the 3rd transistor T 603 and first resistance R 601, second resistance R 602, the 3rd resistance R 603, the 4th resistance R 604 are constituted.Therefore it is more little to work as equivalent resistance REQ, and it is more little to gain.Therefore, when the temperature rising, it is many more that transistor T 601, T602, T603 are switched on, and then equivalent resistance REQ is more little.The signal Vc that is exported also can be more little.
Though only enumerate three transistor Ts 601, T602, T603 at this embodiment; And three resistance R 601 of parallel connection, R602, R603 are as an example; But; Affiliated technical field has common knowledge the knowledgeable and should be known in that the transistorized number and the number of resistance are to change according to different designs.So the present invention is not exceeded with this embodiment.In addition, this area has common knowledge the knowledgeable and should be known in that N transistor npn npn T601, T602, T603 can replace with transmission lock or P transistor npn npn, do not repeat them here.
The 6th embodiment
Fig. 7 then builds another circuit diagram of attenuator 404 of the audio frequency amplifier of thermal protection circuit in the sixth embodiment of the invention.Please refer to Fig. 7, in this embodiment, this attenuator 404 is to be made up of the first transmission lock T701, the second transmission lock T702, the 3rd transmission lock T703, first resistance R 701, second resistance R 702, the 3rd resistance R 703 and 704 of the 4th resistance R.Its relation of coupling illustrates like Fig. 7.Affiliated technical field has common knowledge the knowledgeable and should be known on the actual circuit design, and Temperature Detector 203 can be coupled to the first transmission lock T701, the second transmission lock T702 and the 3rd transmission lock T703 respectively.Same, it for example is the kenel of numerical digit that the temperature control signals TC that Temperature Detector 203 is exported can be designed as.Comparatively different is that transistor T 601, T602 and the T603 of the 5th embodiment can be switched on simultaneously, in this 6th embodiment, for the convenience that designs, transmit lock T701, T702 and T703 and only can select one of them to be switched on.
For present embodiment is described, first assumed temperature has three threshold T1～T3, and T3＞T2＞T1.
When temperature is lower than the first preset temperature T1, only there is the first transmission lock T701 to be switched on, at this moment
Vc＝Va×(R702+R703+R704)/(R701+R702+R703+R704)
When temperature rises between the above-mentioned first preset temperature T1 and the second preset temperature T2, the first transmission lock T701 by by and the second transmission lock T702 is switched on.At this moment
Vc＝Va×(R703+R704)/(R701+R702+R703+R704)
When temperature is elevated between the second preset temperature T2 and the 3rd preset temperature once more, the second transmission lock T702 by by and the 3rd transmission lock T703 is switched on.At this moment
Vc＝Va×(R704)/(R701+R702+R703+R704)
Can be known that by the foregoing description temperature is high more, then the received signal Vc of output stage amplifier 202 is more little.So just can suitably control temperature in certain preset range.Though the foregoing description be with transmission lock T701, T702 and T703 as for example,, this area has common knowledge the knowledgeable and should be known in the function of transmitting the lock indicator cock, any element (for example transistor) with switching function can replace.In addition, though the foregoing description only uses three transmission locks,, this area has common knowledge the knowledgeable and should be known in that the number of transmission lock is to change according to different designs with the number of resistance, so the present invention is not exceeded with this embodiment.
The 7th embodiment
For Temperature Detector 203 can be combined with pre-amplifier 201, output stage amplifier 202 and gain adjustment circuit 204, the 7th embodiment has proposed an integrated audio power amplifying circuit.This integrated audio power amplifying circuit has been integrated Temperature Detector 203, pre-amplifier 201, output stage amplifier 202 and gain adjustment circuit 204 in same integrated circuit.Fig. 8 is the circuit diagram of the integrated audio power amplifying circuit of seventh embodiment of the invention.Please refer to Fig. 8, in this embodiment, Temperature Detector 203 is to use resistance R 801, diode 801, amplifier 802 and reference voltage generator 803, wherein, diode 801 be disposed at output stage amplifier 202 near.Because the barrier voltages (Barrier Potential) of diode 801 can be along with temperature change.For instance, the every rising of barrier voltages of the diode of silicon formation was once reducing 2.5mV.
In addition, can be in order to make temperature signal VTC accurately along with temperature change, the reference voltage VREF of reference voltage generator 803 utilizes energy gap Voltage Reference (Bandgap Voltage Reference) circuit to produce.The reference voltage VREF that this energy gap reference circuits is produced can reach not with temperature change.The circuit of this Temperature Detector 203 be utilize amplifier 802 will along with the barrier voltages of the diode 801 of temperature change with do not amplify with the voltage difference of the reference voltage VREF of temperature change.
The Temperature Detector 203 of this 7th embodiment can be used for controlling the gain adjustment circuit of second embodiment or the attenuator of the 4th embodiment.The Temperature Detector 203 of this 7th embodiment is if will control the attenuator of the 5th embodiment or the 6th embodiment; Must the additional designs ADC, transfer temperature signal VTC to the numerical digit signal to control the switch of above-mentioned the 5th embodiment or the 6th embodiment.
The 8th embodiment
By the foregoing description, can be generalized the heat radiation protection method of an audio amplifier circuit.Fig. 9 is the flow chart of heat radiation protection method of the audio amplifier circuit of eighth embodiment of the invention.Please refer to Fig. 9, the method comprises the following steps:
Step S901: beginning.
Step S902 a: temperature level that detects the pyrotoxin of audio amplifier circuit.
Step S903: judge that whether the said temperature size is greater than a temperature threshold.When temperature level less than this temperature threshold, get back to step S902, continue detected temperatures.When temperature level greater than said temperature threshold, execution in step S904.
Step S904: according to said temperature size, the size of the output signal of adjustment audio amplifier circuit, wherein, when temperature level high more, the size adjustment of the output signal of audio amplifier circuit more little.
In sum, the present invention's spirit is to be temperature protection is integrated gain adjustment mechanism, as long as temperature is higher than preset threshold value, just along with the height of temperature, progressively reduces gain.So, can avoid sound played to interrupt, that also reduces the user acoustically has a uncomfortable feeling.
The specific embodiment that in the detailed description of preferred embodiment, is proposed is only in order to the convenient technology contents that the present invention is described; But not with narrow sense of the present invention be limited to the foregoing description; Situation in spirit that does not exceed the present invention and following claim; The many variations of being done is implemented, and all belongs to the present invention's scope.Therefore the present invention's protection range is as the criterion when looking the claim person of defining.
Claims (18)
1. an audio power amplifying circuit is characterized in that, described circuit comprises:
One pre-amplifier in order to receiving an audio signal, and amplifies, to produce a audio signal after amplifying;
One output stage amplifier receives the audio signal after the described amplification, and exports to the load of back level;
One Temperature Detector is in order to detect the temperature of described output stage amplifier, to export a temperature signal; And
One gain adjustment circuit in order to the size according to temperature signal, is adjusted the size of the audio signal after the amplification that described pre-amplifier exports.
2. audio power amplifying circuit as claimed in claim 1 is characterized in that, described pre-amplifier comprises that one is differential right.
3. audio power amplifying circuit as claimed in claim 2 is characterized in that, described gain adjustment circuit comprises:
One adjustable current source, couple described differential to and described Temperature Detector, in order to the temperature signal of exporting according to described Temperature Detector, adjustment is supplied to a described differential right direct current bias current.
4. audio power amplifying circuit as claimed in claim 1 is characterized in that, described gain adjustment circuit comprises:
One attenuator; Be coupled between described pre-amplifier and the output stage amplifier; Receive the audio signal after the described amplification that described pre-amplifier exports,, adjust the size of the audio signal after the described amplification according to the temperature that described Temperature Detector is exported.
5. audio power amplifying circuit as claimed in claim 4 is characterized in that, described attenuator comprises:
One transistor comprises a grid, one first source-drain electrode and one second source-drain electrode, and its grid receives described temperature signal, and its first source-drain electrode couples described pre-amplifier, and receives the audio signal after the described amplification;
One resistance comprises one first end and one second end, and its first end couples described transistorized first source-drain electrode, and its second end couples and connects voltage altogether.
6. audio power amplifying circuit as claimed in claim 4 is characterized in that, described attenuator comprises:
N transmission lock, each transmission lock comprises an input, an output respectively, each output couples described output stage amplifier;
N+1 resistance; Each resistance comprises one first end and one second end respectively, and first end of first resistance couples described pre-amplifier, and receives the audio signal after the described amplification; Second end of N+1 resistance couples and connects voltage altogether; Second end of K resistance couples first end of K+1 resistance, and second end of K resistance couples the input of K transmission lock
Wherein, according to the size of described temperature signal, the conducting that determines described N transmission lock with end,
Wherein, K and N are natural number, 0＜K≤N.
7. audio power amplifying circuit as claimed in claim 4 is characterized in that, described attenuator comprises:
One amplifier comprises a first input end, one second input and an output;
One first resistance comprises one first end and one second end, and its first end couples described pre-amplifier, and receives the audio signal after the described amplification, and its second end couples the first input end of described amplifier;
N+1 second resistance, each second resistance comprises one first end and one second end respectively, and first end of each second resistance couples the first input end of described amplifier, and second end of first second resistance couples the output of described amplifier;
N transmission lock, each transmission lock comprises an input and an output respectively, and the input of K transmission lock couples second end of K+1 second resistance, and the output of each transmission lock couples the output of described amplifier,
Wherein, according to the size of described temperature signal, the conducting that determines described N transmission lock with end,
Wherein, K and N are natural number, 0＜K≤N.
8. audio power amplifying circuit as claimed in claim 1 is characterized in that, described Temperature Detector comprises:
One thermocouple comprises one first metal wire and one second metal wire, and first end of wherein said first metal wire connects first end of described second metal wire, the described output stage amplifier of first end in contact of wherein said first metal wire;
One amplifier couples second end of described first metal wire and described second metal wire, to export a temperature signal.
9. an integrated audio power amplifying circuit is characterized in that, described circuit comprises
One pre-amplifier in order to receiving an audio signal, and amplifies, to produce a audio signal after amplifying;
One output stage amplifier receives the audio signal after the described amplification, and exports to the load of back level;
One Temperature Detector is in order to detect the temperature of described output stage amplifier, to export a temperature signal; And
One gain adjustment circuit in order to the size according to temperature signal, is adjusted the size of the audio signal after the amplification that described pre-amplifier exports,
Wherein said pre-amplifier, described output stage amplifier, described Temperature Detector and described gain adjustment circuit are integrated in the same integrated circuit.
10. integrated audio power amplifying circuit as claimed in claim 9 is characterized in that, described pre-amplifier comprises that one is differential right.
11. integrated audio power amplifying circuit as claimed in claim 10 is characterized in that, described gain adjustment circuit comprises:
One adjustable current source, couple described differential to and described Temperature Detector, in order to the temperature signal of exporting according to described Temperature Detector, adjustment is supplied to a described differential right direct current bias current.
12. integrated audio power amplifying circuit as claimed in claim 9 is characterized in that, described gain adjustment circuit comprises:
One attenuator; Be coupled between described pre-amplifier and the output stage amplifier; Receive the audio signal after the described amplification that described pre-amplifier exports,, adjust the size of the audio signal after the described amplification according to the temperature that described Temperature Detector is exported.
13. integrated audio power amplifying circuit as claimed in claim 12 is characterized in that, described attenuator comprises:
One transistor comprises a grid, one first source-drain electrode and one second source-drain electrode, and its grid receives described temperature signal, and its first source-drain electrode couples described pre-amplifier, and receives the audio signal after the described amplification;
One resistance comprises one first end and one second end, and its first end couples described transistorized first source-drain electrode, and its second end couples and connects voltage altogether.
14. integrated audio power amplifying circuit as claimed in claim 12 is characterized in that, described attenuator comprises:
N transmission lock, each transmission lock comprises an input, an output respectively, each output couples described output stage amplifier;
N+1 resistance; Each resistance comprises one first end and one second end respectively, and first end of first resistance couples described pre-amplifier, and receives the audio signal after the described amplification; Second end of N+1 resistance couples and connects voltage altogether; Second end of K resistance couples first end of K+1 resistance, and second end of K resistance couples the input of K transmission lock
Wherein, according to the size of described temperature signal, the conducting that determines described N transmission lock with end,
Wherein, K and N are natural number, 0＜K≤N.
15. integrated audio power amplifying circuit as claimed in claim 12 is characterized in that, described attenuator comprises:
One amplifier comprises a first input end, one second input and an output;
One first resistance comprises one first end and one second end, and its first end couples described pre-amplifier, and receives the audio signal after the described amplification, and its second end couples the first input end of described amplifier;
N+1 second resistance, each second resistance comprises one first end and one second end respectively, and first end of each second resistance couples the first input end of described amplifier, and second end of first second resistance couples the output of described amplifier;
N transmission lock, each transmission lock comprises an input and an output respectively, and the input of K transmission lock couples second end of K+1 second resistance, and the output of each transmission lock couples the output of described amplifier,
Wherein, according to the size of described temperature signal, the conducting that determines described N transmission lock with end,
Wherein, K and N are natural number, 0＜K≤N.
16. integrated audio power amplifying circuit as claimed in claim 9 is characterized in that, described Temperature Detector comprises:
One diode comprises an anode and a negative electrode, and described anode couples a bias voltage, and described negative electrode couples and connects voltage altogether, and wherein said diode arrangement is near the pyrotoxin of described integrated audio power amplifying circuit;
One reference voltage generator is in order to produce a reference voltage;
One amplifier; Comprise a first input end, one second input and an output, its first input end couples the anode of described diode, and its second input couples described reference voltage generator; To receive described reference voltage, its output is in order to export a temperature signal.
17. integrated audio power amplifying circuit as claimed in claim 16 is characterized in that described reference voltage generator comprises a bandgap reference circuit.
18. the heat radiation protection method of an audio amplifier circuit is characterized in that, described method comprises:
(a) temperature level of the pyrotoxin of the described audio amplifier circuit of detection;
(b) judge that whether described temperature level is greater than a temperature threshold;
(c) when described temperature level less than described temperature threshold, get back to step (b); And
(d) when described temperature level greater than described temperature threshold, according to described temperature level, adjust the size of the output signal of described audio amplifier circuit,
Wherein, described temperature level is high more, the output signal of described audio amplifier circuit big or small controlled more little.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010534377.7A CN102468808B (en) | 2010-11-05 | 2010-11-05 | Thermal protection circuit and method of audio power amplification circuit |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201010534377.7A CN102468808B (en) | 2010-11-05 | 2010-11-05 | Thermal protection circuit and method of audio power amplification circuit |
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| CN102468808A true CN102468808A (en) | 2012-05-23 |
| CN102468808B CN102468808B (en) | 2014-10-29 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104954935A (en) * | 2014-03-26 | 2015-09-30 | 瑞昱半导体股份有限公司 | Audio device and control method thereof |
| CN105305975A (en) * | 2014-07-22 | 2016-02-03 | 无锡麟力科技有限公司 | Temperature protection modulation circuit of Class D audio power amplifier |
| CN108353238A (en) * | 2015-09-28 | 2018-07-31 | 思睿逻辑国际半导体有限公司 | Speaker protection circuit system and method |
| CN108769813A (en) * | 2018-04-28 | 2018-11-06 | 郑州易通众联电子科技有限公司 | Processing method and processing device for TV fever |
| CN110212496A (en) * | 2019-05-29 | 2019-09-06 | 上海韦尔半导体股份有限公司 | A kind of temperature-control circuit and method |
| CN115079747A (en) * | 2022-06-29 | 2022-09-20 | 重庆长安汽车股份有限公司 | Vehicle-mounted controller temperature control method and system, electronic equipment and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5107389A (en) * | 1989-05-22 | 1992-04-21 | Sgs-Thomson Microelectronics S.R.L. | Circuit for limiting temperature without distortion in audio power amplifiers |
| US7342455B2 (en) * | 2004-05-28 | 2008-03-11 | Broadcom Corporation | Temperature sensor insensitive to device offsets with independent adjustment of slope and reference temperature |
| CN100483931C (en) * | 2002-09-23 | 2009-04-29 | 哈曼国际工业有限公司 | Heat protective system of amplifier output stage |
| US7705669B2 (en) * | 2008-05-06 | 2010-04-27 | Himax Media Solutions, Inc. | Preamplifier and method for calibrating offsets therein |
-
2010
- 2010-11-05 CN CN201010534377.7A patent/CN102468808B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5107389A (en) * | 1989-05-22 | 1992-04-21 | Sgs-Thomson Microelectronics S.R.L. | Circuit for limiting temperature without distortion in audio power amplifiers |
| CN100483931C (en) * | 2002-09-23 | 2009-04-29 | 哈曼国际工业有限公司 | Heat protective system of amplifier output stage |
| US7342455B2 (en) * | 2004-05-28 | 2008-03-11 | Broadcom Corporation | Temperature sensor insensitive to device offsets with independent adjustment of slope and reference temperature |
| US7705669B2 (en) * | 2008-05-06 | 2010-04-27 | Himax Media Solutions, Inc. | Preamplifier and method for calibrating offsets therein |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104954935A (en) * | 2014-03-26 | 2015-09-30 | 瑞昱半导体股份有限公司 | Audio device and control method thereof |
| CN104954935B (en) * | 2014-03-26 | 2018-11-06 | 瑞昱半导体股份有限公司 | Audio device and its control method |
| CN105305975A (en) * | 2014-07-22 | 2016-02-03 | 无锡麟力科技有限公司 | Temperature protection modulation circuit of Class D audio power amplifier |
| CN108353238A (en) * | 2015-09-28 | 2018-07-31 | 思睿逻辑国际半导体有限公司 | Speaker protection circuit system and method |
| CN108353238B (en) * | 2015-09-28 | 2021-06-01 | 思睿逻辑国际半导体有限公司 | Speaker protection circuitry and method |
| CN108769813A (en) * | 2018-04-28 | 2018-11-06 | 郑州易通众联电子科技有限公司 | Processing method and processing device for TV fever |
| CN110212496A (en) * | 2019-05-29 | 2019-09-06 | 上海韦尔半导体股份有限公司 | A kind of temperature-control circuit and method |
| CN110212496B (en) * | 2019-05-29 | 2024-05-28 | 上海韦尔半导体股份有限公司 | Temperature control circuit and method |
| CN115079747A (en) * | 2022-06-29 | 2022-09-20 | 重庆长安汽车股份有限公司 | Vehicle-mounted controller temperature control method and system, electronic equipment and storage medium |
| CN115079747B (en) * | 2022-06-29 | 2023-08-22 | 重庆长安汽车股份有限公司 | Temperature control method and system for vehicle-mounted controller, electronic equipment and storage medium |
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