CN101729030A - D class amplifier and control method thereof - Google Patents
D class amplifier and control method thereof Download PDFInfo
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- CN101729030A CN101729030A CN200810169462A CN200810169462A CN101729030A CN 101729030 A CN101729030 A CN 101729030A CN 200810169462 A CN200810169462 A CN 200810169462A CN 200810169462 A CN200810169462 A CN 200810169462A CN 101729030 A CN101729030 A CN 101729030A
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Abstract
The invention relates to a D class amplifier which comprises a first comparator, a second comparator, a third comparator, a switching circuit and a driving circuit and is characterized in that the first comparator compares a sawtooth wave signal and a first voltage to generate a first signal; the second comparator compares the sawtooth wave signal and a second voltage to generate a second signal; the third comparator is provided with a first input and a second input, the first input of the third comparator is connected with an input signal, and the third comparator compares signals on the first input and the second input to generate a pulse-width modulation (PWM) signal; the switching circuit switches the sawtooth wave signal, the first voltage or the second voltage to the second input of the third comparator according to the first signal and the second signal; and the driving circuit generates a third signal according to one of the first signal and the second signal and the PWM signal to drive a load on the output of the D class amplifier.
Description
Technical field
The present invention relates to a kind of D class A amplifier A, specifically, is a kind of D class A amplifier A and control method thereof with minimum pulse.
Background technology
Fig. 1 is known D class A amplifier A 10, comprise a control circuit 12 and an output stage 14, control circuit 12 produces output signal VOUTP and VOUTN according to an input signal AudioIN, and PMOS transistor P1 in output signal VOUTP and the VOUTN switching output stage 14 and P2 and nmos pass transistor N1 and N2 are to drive load.For fear of causing output stage 14 short circuit to occur, therefore can provide a minimum pulse mechanism to make output signal VOUTP or VOUTN have minimum pulse width because of the work period of output signal VOUTP or VOUTN is too small.
Known minimum pulse production method has two kinds, a kind of is as the U.S. the 6th, 262, described in No. 632 patents, produce by the time delay difference of two input channels and to click pulse (oneshot pulse), another kind then is as the U.S. the 6th, 847, No. 257 patent is described, and the rising edge of the switch pulse of detection one change and falling edge are to produce minimum pulse.Yet, when aforementioned manner is higher than the amplitude of inner switching waveform at the amplitude of input signal AudioIN, can't produce minimum pulse, thereby cause output stage 14 sustained short-circuits.In addition, minimum pulse also can cause non-linear phenomena.
Therefore known D class A amplifier A exists above-mentioned all inconvenience and problem.
Summary of the invention
Purpose of the present invention is to propose a kind of D class A amplifier A and control method thereof.
For achieving the above object, technical solution of the present invention is:
A kind of D class A amplifier A comprises one first comparator, one second comparator, and one the 3rd comparator, one switches circuit and one drive circuit, it is characterized in that:
Described first comparator, relatively a sawtooth signal and one first voltage produce one first signal;
Described second comparator, more described sawtooth signal and one second voltage produce a secondary signal;
One the 3rd comparator has one first input and one second input, and first input of described the 3rd comparator connects an input signal, and the signal in its two input of described the 3rd comparator comparison produces a pulse-width modulation signal;
One switches circuit, described sawtooth signal, first voltage or second voltage is switched to second input of described the 3rd comparator according to described first and second signal;
One drive circuit produces one the 3rd signal for the load that drives in described D class A amplifier A output according to one of them and described pulse-width modulation signal of described first and second signal.
D class A amplifier A of the present invention can also be further achieved by the following technical measures.
Aforesaid D class A amplifier A, the waveform of the signal in second input of wherein said the 3rd comparator is an irregular quadrilateral.
Aforesaid D class A amplifier A, wherein said commutation circuit comprises:
One first switch is connected between second input of described first voltage and described the 3rd comparator, is controlled by described first signal;
One second switch is connected between second input of described sawtooth signal and described the 3rd comparator, is controlled by described first and second signal;
One the 3rd switch is connected between second input of described second voltage and described the 3rd comparator, is controlled by described secondary signal.
Aforesaid D class A amplifier A, wherein said drive circuit comprise one or door have one of them and the described pulse-width modulation signal that two inputs connect described first and second signal respectively, produce described the 3rd signal according to this.
Aforesaid D class A amplifier A, the pulse duration of wherein said first signal can change by regulating described first voltage.
Aforesaid D class A amplifier A, the pulse duration of wherein said secondary signal can change by regulating described second voltage.
A kind of control method of D class A amplifier A is characterized in that may further comprise the steps:
First step: relatively a sawtooth signal and one first voltage produce one first signal;
Second step: more described sawtooth signal and one second voltage produce a secondary signal;
Third step: switch described sawtooth signal, first voltage or second voltage to one end points according to described first and second signal, on described end points, to produce one the 3rd signal;
The 4th step: more described the 3rd signal and an input signal produce a pulse-width modulation signal;
The 5th step: produce one the 4th signal according to described first and second signal one of them and described pulse-width modulation signal;
The 6th step: according to the load of described the 4th signal driving in described D class A amplifier A output.
The control method of D class A amplifier A of the present invention can also be further achieved by the following technical measures.
Aforesaid control method, the waveform of wherein said the 3rd signal are irregular quadrilateral.
Aforesaid control method, the pulse duration of wherein said first signal is determined by described first voltage.
Aforesaid control method, the pulse duration of wherein said secondary signal is determined by described second voltage.
A kind of D class A amplifier A comprises one first comparator, one second comparator, one the 3rd comparator, one first commutation circuit, one first drive circuit, one the 4th comparator, one the 5th comparator, one the 6th comparator, one second commutation circuit and one second drive circuit is characterized in that:
One first comparator, relatively one first sawtooth signal and one first voltage produce one first signal;
One second comparator, more described first sawtooth signal and one second voltage produce a secondary signal;
One the 3rd comparator has one first input and one second input, and first input of described the 3rd comparator connects an input signal, and the signal in its two input of described the 3rd comparator comparison produces one first pulse-width modulation signal;
One first commutation circuit switches to second of described the 3rd comparator according to described first and second signal with described first sawtooth signal, first voltage or second voltage and imports;
One first drive circuit produces one the 4th signal according to one the 3rd signal and the described first pulse-width modulation signal, and described the 3rd signal is one of them of described first and second signal;
One the 4th comparator, relatively one second sawtooth signal and a tertiary voltage produce one the 5th signal;
One the 5th comparator, more described second sawtooth signal and one the 4th voltage produce one the 6th signal;
One the 6th comparator has one first input and one second input, and first input of described the 6th comparator connects one second input signal, and the signal in its two input of described the 6th comparator comparison produces one second pulse-width modulation signal;
One second commutation circuit switches to second of described the 6th comparator according to the described the 5th and the 6th signal with described second sawtooth signal, tertiary voltage or the 4th voltage and imports;
One second drive circuit, produce one the 8th signal according to one the 7th signal and the described second pulse-width modulation signal, described the 7th signal is one of them of the described the 5th and the 6th signal, and the described the 4th and the 8th signal is for the load that drives in the output of described D class A amplifier A.
Aforesaid D class A amplifier A, the waveform of the signal in second input of wherein said the 3rd comparator is an irregular quadrilateral.
Aforesaid D class A amplifier A, the waveform of the signal in second input of wherein said the 6th comparator is an irregular quadrilateral.
Aforesaid D class A amplifier A, wherein said first commutation circuit comprises:
One first switch is connected between second input of described first voltage and described the 3rd comparator, is controlled by described first signal;
One second switch is connected between second input of described first sawtooth signal and described the 3rd comparator, is controlled by described first and second signal;
One the 3rd switch is connected between second input of described second voltage and described the 3rd comparator, is controlled by described secondary signal.
Aforesaid D class A amplifier A, wherein said second commutation circuit comprises:
One first switch is connected between second input of described tertiary voltage and described the 6th comparator, is controlled by described the 5th signal;
One second switch is connected between second input of described second sawtooth signal and described the 6th comparator, is controlled by the described the 5th and the 6th signal;
One the 3rd switch is connected between second input of described the 4th voltage and described the 6th comparator, is controlled by described the 6th signal.
Aforesaid D class A amplifier A, wherein said first drive circuit comprise one or the door have two the input connect described the 3rd signal and the described first pulse-width modulation signal respectively, produce described the 4th signal according to this.
Aforesaid D class A amplifier A, wherein said second drive circuit comprise one or the door have two the input connect described the 7th signal and the described second pulse-width modulation signal respectively, produce described the 8th signal according to this.
Aforesaid D class A amplifier A, the pulse duration of wherein said first signal can change by regulating described first voltage.
Aforesaid D class A amplifier A, the pulse duration of wherein said secondary signal can change by regulating described second voltage.
Aforesaid D class A amplifier A, the pulse duration of wherein said the 5th signal can change by regulating described tertiary voltage.
Aforesaid D class A amplifier A, the pulse duration of wherein said the 6th signal can change by regulating described the 4th voltage.
Aforesaid D class A amplifier A wherein more comprises:
One current source;
One electric capacity;
One first switch is connected between described current source and the electric capacity;
One second switch, in parallel with described electric capacity;
One delay circuit, the switching of described first and second switch of control is to control described electric capacity
Discharge and recharge to produce described second sawtooth signal.
Aforesaid D class A amplifier A, when the amplitude that wherein said delay circuit more is included in described first input signal is gone up the amplitude of signal greater than second input of described the 3rd comparator, detect the error amount between described the 4th signal and the described first pulse-width modulation signal, postpone described second sawtooth signal according to this.
Aforesaid D class A amplifier A, wherein said electric capacity are variable capacitance, and its capacitance is determined by described delay circuit.
Aforesaid D class A amplifier A wherein more comprises:
One the 7th comparator, more described second sawtooth signal and one first reference voltage;
One the 8th comparator, more described second sawtooth signal and one second reference voltage;
One flip-flop, according to the described the 7th and the output of the 8th comparator produce one the 9th signal and give described delay circuit, determine the capacitance of described electric capacity according to this.
A kind of control method of D class A amplifier A is characterized in that may further comprise the steps:
First step: relatively one first sawtooth signal and one first voltage produce one first signal;
Second step: more described first sawtooth signal and one second voltage produce a secondary signal;
Third step: switch described first sawtooth signal, first voltage or second voltage to one end points according to described first and second signal, on described end points, to produce one the 3rd signal;
The 4th step: more described the 3rd signal and one first input signal produce one first pulse-width modulation signal;
The 5th step: produce the First Five-Year Plan signal according to one the 4th signal and the described first pulse-width modulation signal, described the 4th signal be described first and second signal one of them;
The 6th step: relatively one second sawtooth signal and a tertiary voltage produce one the 6th signal;
The 7th step: more described second sawtooth signal and one the 4th voltage produce one the 7th signal;
The 8th step: switch described second sawtooth signal, tertiary voltage or the 4th voltage to one end points according to the described the 6th and the 7th signal, on described end points, to produce one the 8th signal;
The 9th step: more described the 8th signal and one second input signal produce one second pulse-width modulation signal;
The tenth step: produce 1 the tenth signal according to one the 9th signal and the described second pulse-width modulation signal, described the 9th signal be the described the 6th and the 7th signal one of them;
The 11 step: according to the load of the described the 5th and the tenth signal driving in described D class A amplifier A output.
Aforesaid control method, the waveform of wherein said the 3rd signal are irregular quadrilateral.
Aforesaid control method, the waveform of wherein said the 8th signal are irregular quadrilateral.
Aforesaid control method wherein more comprises and regulates described first voltage to change the pulse duration of described first signal.
Aforesaid control method wherein more comprises and regulates described second voltage to change the pulse duration of described secondary signal.
Aforesaid control method wherein more comprises and regulates described tertiary voltage to change the pulse duration of described the 6th signal.
Aforesaid control method more comprises and regulates described the 4th voltage to change the pulse duration of described the 7th signal.
Aforesaid control method wherein more comprises:
During greater than the amplitude of described the 3rd signal, detect the error amount between described the 5th signal and the described first pulse-width modulation signal at the amplitude of described first input signal;
Postpone described second sawtooth signal according to described error amount.
Aforesaid control method wherein more comprises:
Control discharging and recharging of an electric capacity to produce described second sawtooth signal;
Stop discharging and recharging according to described the 5th signal and the first pulse-width modulation signal to described electric capacity to postpone described second sawtooth signal.
Aforesaid control method wherein saidly stops the step that discharges and recharges to described electric capacity according to described the 5th signal and the first pulse-width modulation signal and comprises and stop discharging and recharging described electric capacity when described the 5th signal and the described first pulse-width modulation signal inversion.
Aforesaid control method wherein more comprises:
More described second sawtooth signal and one first reference voltage produce one first comparison signal;
More described second sawtooth signal and one second reference voltage produce one second comparison signal;
Adjust the capacitance of described electric capacity with described first and second comparison signal.
After adopting technique scheme, D class A amplifier A of the present invention and control method thereof have the advantage of minimum pulse.
Description of drawings
Fig. 1 is known D class A amplifier A schematic diagram;
Fig. 2 is a first embodiment of the present invention schematic diagram;
Fig. 3 is the oscillogram of signal among Fig. 2;
Fig. 4 is second embodiment of the present invention illustration intention;
Fig. 5 is the oscillogram of signal among Fig. 4;
Fig. 6 is for providing the sawtooth generator schematic diagram of sawtooth signal Vsaw2.
Embodiment
Below in conjunction with embodiment and accompanying drawing thereof the present invention is illustrated further.
Now see also Fig. 2 and Fig. 3, Fig. 2 is a first embodiment of the present invention schematic diagram, and Fig. 3 is the oscillogram of signal among Fig. 2; As shown in the figure, in the described D class A amplifier A 20, comparator 22 comparative voltage VL and sawtooth signal Vsaw produce signal S1, the waveform of sawtooth signal Vsaw is shown in the waveform 38 of Fig. 3, comparator 24 comparative voltage VH and sawtooth signal Vsaw produce signal S2, commutation circuit 26 comprises that switch SW 1 is connected between the noninverting input of voltage VL and comparator 30, switch SW 2 is connected between the noninverting input of sawtooth signal Vsaw and comparator 30, switch SW 3 is connected between the noninverting input of voltage VH and comparator 30, the signal S1 control switch SW1 that comparator 22 is exported, when sawtooth signal SAW is lower than voltage VL, switch SW 1 is opened (turn on), the signal S2 control switch SW3 that comparator 24 is exported, when sawtooth signal SAW is higher than voltage VH, switch SW 3 is opened, NOR gate 28 produces signal S3 control switch SW2 according to signal S1 and S2, when signal S1 and S2 are low level, switch SW 2 is opened, commutation circuit 26 according to signal S1 and S2 with voltage VL, sawtooth signal Vsaw or voltage VH switch to the noninverting input of comparator 30, thereby in the noninverting input of comparator 30, produce signal Tra, the waveform of signal Tra is irregular quadrilateral (trapezoid), shown in the waveform 40 of Fig. 3, comparator 30 comparator input signal AudioIn and signal Tra produce pulse-width modulation signal Vpwm, the waveform of signal AudioIn is shown in the waveform 36 of Fig. 3, and drive circuit 32 comprises or door 34 produces signal Minipulse for the loud speaker that drives in 20 outputs of D class A amplifier A according to signal S2 and pulse-width modulation signal Vpwm.
In described D class A amplifier A 20, sawtooth signal and the input signal AudioIn known with the signal Tra replacement of irregular quadrilateral waveform relatively produce pulse-width modulation signal Vpwm, in addition, signal S2 by voltage VH and sawtooth signal Vsaw generation fixed pulse width, because signal S2 and input signal AudioIn are irrelevant, when therefore even the amplitude of input signal AudioIn is greater than signal Tra, signal Minipulse still has minimum pulse, when the pulse duration of pulse-width modulation signal Vpwm during greater than the pulse duration of signal S2, described signal Minipulse equals pulse-width modulation signal Vpwm, when the pulse duration of pulse-width modulation signal Vpwm during less than the pulse duration of signal S2, signal Minipulse equals signal S2.The pulse duration of this external signal S2 can be adjusted by offset voltage VH, therefore can reach best PWM energy equivalence and output to input amplitude.In the present embodiment, be to utilize signal S2 and pulse-width modulation signal Vpwm to produce signal Minipulse, in other embodiments, also can utilize signal S1 and pulse-width modulation signal Vpwm to produce signal Minipulse.
Fig. 4 is a second embodiment of the present invention schematic diagram, in described D class A amplifier A 50, comparator 52 produces signal S4 according to voltage VL1 and sawtooth signal Vsaw1, comparator 54 produces signal S5 according to voltage VH1 and sawtooth signal Vsaw1, commutation circuit 56 according to signal S4 and S5 with voltage VL1, sawtooth signal Vsaw1 or voltage VH1 switch to the noninverting input of comparator 60, thereby in the noninverting input of comparator 60, produce a signal Tra1 with irregular quadrilateral waveform, commutation circuit 56 comprises that NOR gate 58 produces signal S6 according to signal S4 and S5, switch SW 4 is connected between the noninverting input of voltage VL1 and comparator 60 and is controlled by signal S4, switch SW 5 is connected between the noninverting input of sawtooth signal Vsaw1 and comparator 60 and is controlled by signal S6, switch SW 6 is connected between the noninverting input of voltage VH1 and comparator 60 and is controlled by signal S5, comparator 60 comparison signal Tra1 and input signal AudioInP produce pulse-width modulation signal Vpwm1, and drive circuit 62 comprises or door 64 produces signal MinipulseP according to pulse-width modulation signal Vpwm1 and signal S 5.Comparator 66 produces signal S7 according to voltage VL2 and sawtooth signal Vsaw2, comparator 68 produces signal S8 according to voltage VH2 and sawtooth signal Vsaw2, commutation circuit 70 according to signal S7 and S8 with voltage VL2, sawtooth signal Vsaw2 or voltage VH2 switch to the noninverting input of comparator 74, thereby in the noninverting input of comparator 74, produce a signal Tra2 with irregular quadrilateral waveform, commutation circuit 70 comprises that NOR gate 72 produces signal S9 according to signal S7 and S8, switch SW 7 is connected between the noninverting input of voltage VL2 and comparator 74 and is controlled by signal S7, switch SW 8 is connected between the noninverting input of sawtooth signal Vsaw2 and comparator 74 and is controlled by signal S9, switch SW 9 is connected between the noninverting input of voltage VH2 and comparator 74 and is controlled by signal S8, comparator 74 comparison signal Tra2 and input signal AudioInN produce pulse-width modulation signal Vpwm2, drive circuit 76 comprises or door 78 produces signal MinipulseN according to pulse-width modulation signal Vpwm2 and signal S 8, and signal MinipulseP and MinipulseN are in order to drive the loud speaker in 50 outputs of D class A amplifier A.
The oscillogram of signal in Fig. 5 displayed map 4, wherein waveform 80 is the sawtooth signal Vsaw2 that is not delayed, and waveform 82 is the sawtooth signal Vsaw2 after postponing, and waveform 84 is pulse-width modulation signal Vpwm1, waveform 86 is signal MinipulseP, and waveform 88 is signal MinipulseN.Fig. 6 shows the sawtooth generator 90 that sawtooth signal Vsaw2 is provided, capacitor C A wherein, CK, CL and CM and switch SW A, SWK and SWL form a variable capacitance 94, current source 92 provides decides electric current DC in order to electric capacity 94 is charged, switch SW 10 is connected between current source 92 and the electric capacity 94, switch SW 11 is in parallel with electric capacity 94, switching the discharging and recharging of N position ON/OFF selector and delay circuit 96 control switch SW10 and SW11 with control capacitance 94, and then generation sawtooth signal Vsaw2, in addition, N position ON/OFF selector and delay circuit 96 all right diverter switch SWA, SWK and SWL are with the capacitance of decision equivalent capacity 94, resistance R 1, R2 and R3 branch pressure voltage Vcc produce voltage V1 and V2, comparator 98 is sawtooth signal Vsaw2 and voltage V1 generation comparison signal Ss relatively, comparator 100 is sawtooth signal Vsaw2 and voltage V2 generation comparison signal Sr relatively, and flip-flop 102 is according to signal Ss and Sr produces signal Sq and Sqn gives N position ON/OFF selector and delay circuit 96.In sawtooth generator 90, N position ON/OFF selector and delay circuit 96 produce at random control signal come diverter switch SWA ..., SWK and SWL to be to change the capacitance of electric capacity 94, current source 92 is to provide to decide electric current DC to electric capacity 94 chargings again, the time that therefore each sawtooth signal Vsaw2 reaches voltage V1 is inequality, and then the sawtooth signal Vsaw2 that is vibrated at random.
With reference to Fig. 5 and Fig. 6, when the amplitude of input signal AudioInP during greater than the amplitude of signal Tra1, N position ON/OFF selector and delay circuit 96 detect the error amount of pulse-width modulation signal Vpwm1 and signal MinipulseP, and according to the pulse duration of described error amount conditioning signal MinipulseN, comprise the PWM work period so that the total pulse widths on Ti sound device is similar to actual input audible signals, thereby improve the non-linear phenomena that causes because of minimum pulse.And, when time t 1, pulse-width modulation signal Vpwm1 and signal MinipulseP be homophase not, shown in waveform 84 and 86, therefore N position ON/OFF selector and delay circuit 96 are closed (turnoff) switch SW 11 to keep the accurate position of sawtooth signal Vsaw2 this moment, when time t2, N position ON/OFF selector and delay circuit 96 are just opened switch SW 11, thereby make sawtooth signal Vsaw2 delay_1 time of delay, same, during time t3 to t4, pulse-width modulation signal Vpwm1 and signal MinipulseP be homophase not, so N position ON/OFF selector and delay circuit 96 off switch SW11 are so that sawtooth signal Vsaw2 delay_2 time of delay, in other words, has error amount delay_1+delay_2 between pulse-width modulation signal Vpwm1 and the signal MinipulseP, therefore N position ON/OFF selector and delay circuit 96 postpone sawtooth signal Vsaw2 the time of delay_1+delay_2, shown in waveform 80 and 82, and then make signal Tra2 postpone the time of delay_1+delay_2, so the pulse duration of signal MinipulseN will increase delay_1+delay_2, shown in waveform 88.
Above embodiment is only for the usefulness that the present invention is described, but not limitation of the present invention, person skilled in the relevant technique under the situation that does not break away from the spirit and scope of the present invention, can also be made various conversion or variation.Therefore, all technical schemes that are equal to also should belong to category of the present invention, should be limited by each claim.
The assembly symbol description
10 D class A amplifier As
12 control circuit
14 output levels
20 D class A amplifier As
22 comparators
24 comparators
26 commutation circuits
28 NOR gate
30 comparators
32 drive circuits
34 or the door
The waveform of 36 input signal AudioIn
The waveform of 38 sawtooth signal Vsaw
The waveform of 40 signal Tra
50 D class A amplifier As
52 comparators
54 comparators
56 commutation circuits
58 NOR gate
60 comparators
62 drive circuits
64 or the door
66 comparators
68 comparators
70 commutation circuits
72 NOR gate
74 comparators
76 drive circuits
78 or the door
The waveform of the 80 sawtooth signal Vsaw2 that are not delayed
The waveform of sawtooth signal Vsaw2 after 82 delays
The waveform of 84 pulse-width modulation signal Vpwm1
The waveform of 86 signal MinipulseP
The waveform of 88 signal MinipulseN
90 sawtooth generators
92 current sources
94 electric capacity
96 N position ON/OFF selector and delay circuits
98 comparators
100 comparators
102 flip-flops.
Claims (36)
1. a D class A amplifier A comprises one first comparator, one second comparator, and one the 3rd comparator, one switches circuit and one drive circuit, it is characterized in that:
Described first comparator, relatively a sawtooth signal and one first voltage produce one first signal;
Described second comparator, more described sawtooth signal and one second voltage produce a secondary signal;
One the 3rd comparator has one first input and one second input, and first input of described the 3rd comparator connects an input signal, and the signal in its two input of described the 3rd comparator comparison produces a pulse-width modulation signal;
One switches circuit, described sawtooth signal, first voltage or second voltage is switched to second input of described the 3rd comparator according to described first and second signal;
One drive circuit produces one the 3rd signal for the load that drives in described D class A amplifier A output according to one of them and described pulse-width modulation signal of described first and second signal.
2. D class A amplifier A as claimed in claim 1 is characterized in that, the waveform of the signal in second input of described the 3rd comparator is an irregular quadrilateral.
3. D class A amplifier A as claimed in claim 1 is characterized in that, described commutation circuit comprises:
One first switch is connected between second input of described first voltage and described the 3rd comparator, is controlled by described first signal;
One second switch is connected between second input of described sawtooth signal and described the 3rd comparator, is controlled by described first and second signal;
One the 3rd switch is connected between second input of described second voltage and described the 3rd comparator, is controlled by described secondary signal.
4. D class A amplifier A as claimed in claim 1 is characterized in that, described drive circuit comprise one or door have one of them and the described pulse-width modulation signal that two inputs connect described first and second signal respectively, produce described the 3rd signal according to this.
5. D class A amplifier A as claimed in claim 1 is characterized in that, the pulse duration of described first signal can change by regulating described first voltage.
6. D class A amplifier A as claimed in claim 1 is characterized in that, the pulse duration of described secondary signal can change by regulating described second voltage.
7. the control method of a D class A amplifier A is characterized in that may further comprise the steps:
First step: relatively a sawtooth signal and one first voltage produce one first signal;
Second step: more described sawtooth signal and one second voltage produce a secondary signal;
Third step: switch described sawtooth signal, first voltage or second voltage to one end points according to described first and second signal, on described end points, to produce one the 3rd signal;
The 4th step: more described the 3rd signal and an input signal produce a pulse-width modulation signal;
The 5th step: produce one the 4th signal according to described first and second signal one of them and described pulse-width modulation signal;
The 6th step: according to the load of described the 4th signal driving in described D class A amplifier A output.
8. control method as claimed in claim 7 is characterized in that, the waveform of described the 3rd signal is an irregular quadrilateral.
9. control method as claimed in claim 7 is characterized in that, the pulse duration of described first signal is determined by described first voltage.
10. control method as claimed in claim 7 is characterized in that, the pulse duration of described secondary signal is determined by described second voltage.
11. a D class A amplifier A comprises one first comparator, one second comparator, one the 3rd comparator, one first commutation circuit, one first drive circuit, one the 4th comparator, one the 5th comparator, one the 6th comparator, one second commutation circuit and one second drive circuit is characterized in that:
One first comparator, relatively one first sawtooth signal and one first voltage produce one first signal;
One second comparator, more described first sawtooth signal and one second voltage produce a secondary signal;
One the 3rd comparator has one first input and one second input, and first input of described the 3rd comparator connects an input signal, and the signal in its two input of described the 3rd comparator comparison produces one first pulse-width modulation signal;
One first commutation circuit switches to second of described the 3rd comparator according to described first and second signal with described first sawtooth signal, first voltage or second voltage and imports;
One first drive circuit produces one the 4th signal according to one the 3rd signal and the described first pulse-width modulation signal, and described the 3rd signal is one of them of described first and second signal;
One the 4th comparator, relatively one second sawtooth signal and a tertiary voltage produce one the 5th signal;
One the 5th comparator, more described second sawtooth signal and one the 4th voltage produce one the 6th signal;
One the 6th comparator has one first input and one second input, and first input of described the 6th comparator connects one second input signal, and the signal in its two input of described the 6th comparator comparison produces one second pulse-width modulation signal;
One second commutation circuit switches to second of described the 6th comparator according to the described the 5th and the 6th signal with described second sawtooth signal, tertiary voltage or the 4th voltage and imports;
One second drive circuit, produce one the 8th signal according to one the 7th signal and the described second pulse-width modulation signal, described the 7th signal is one of them of the described the 5th and the 6th signal, and the described the 4th and the 8th signal is for the load that drives in the output of described D class A amplifier A.
12. D class A amplifier A as claimed in claim 11 is characterized in that, the waveform of the signal in second input of described the 3rd comparator is an irregular quadrilateral.
13. D class A amplifier A as claimed in claim 11 is characterized in that, the waveform of the signal in second input of described the 6th comparator is an irregular quadrilateral.
14. D class A amplifier A as claimed in claim 11 is characterized in that, described first commutation circuit comprises:
One first switch is connected between second input of described first voltage and described the 3rd comparator, is controlled by described first signal;
One second switch is connected between second input of described first sawtooth signal and described the 3rd comparator, is controlled by described first and second signal;
One the 3rd switch is connected between second input of described second voltage and described the 3rd comparator, is controlled by described secondary signal.
15. D class A amplifier A as claimed in claim 11 is characterized in that, described second commutation circuit comprises:
One first switch is connected between second input of described tertiary voltage and described the 6th comparator, is controlled by described the 5th signal;
One second switch is connected between second input of described second sawtooth signal and described the 6th comparator, is controlled by the described the 5th and the 6th signal;
One the 3rd switch is connected between second input of described the 4th voltage and described the 6th comparator, is controlled by described the 6th signal.
16. D class A amplifier A as claimed in claim 11 is characterized in that, described first drive circuit comprise one or the door have two the input connect described the 3rd signal and the described first pulse-width modulation signal respectively, produce described the 4th signal according to this.
17. D class A amplifier A as claimed in claim 11 is characterized in that, described second drive circuit comprise one or the door have two the input connect described the 7th signal and the described second pulse-width modulation signal respectively, produce described the 8th signal according to this.
18. D class A amplifier A as claimed in claim 11 is characterized in that, the pulse duration of described first signal can change by regulating described first voltage.
19. D class A amplifier A as claimed in claim 11 is characterized in that, the pulse duration of described secondary signal can change by regulating described second voltage.
20. D class A amplifier A as claimed in claim 11 is characterized in that, the pulse duration of described the 5th signal can change by regulating described tertiary voltage.
21. D class A amplifier A as claimed in claim 11 is characterized in that, the pulse duration of described the 6th signal can change by regulating described the 4th voltage.
22. D class A amplifier A as claimed in claim 11 is characterized in that, more comprises:
One current source;
One electric capacity;
One first switch is connected between described current source and the electric capacity;
One second switch, in parallel with described electric capacity;
One delay circuit, the switching of described first and second switch of control is to control the discharging and recharging to produce described second sawtooth signal of described electric capacity.
23. D class A amplifier A as claimed in claim 22, it is characterized in that, when the amplitude that described delay circuit more is included in described first input signal is gone up the amplitude of signal greater than second input of described the 3rd comparator, detect the error amount between described the 4th signal and the described first pulse-width modulation signal, postpone described second sawtooth signal according to this.
24. D class A amplifier A as claimed in claim 22 is characterized in that, described electric capacity is variable capacitance, and its capacitance is determined by described delay circuit.
25. D class A amplifier A as claimed in claim 24 is characterized in that, more comprises:
One the 7th comparator, more described second sawtooth signal and one first reference voltage;
One the 8th comparator, more described second sawtooth signal and one second reference voltage;
One flip-flop, according to the described the 7th and the output of the 8th comparator produce one the 9th signal and give described delay circuit, determine the capacitance of described electric capacity according to this.
26. the control method of a D class A amplifier A is characterized in that may further comprise the steps:
First step: relatively one first sawtooth signal and one first voltage produce one first signal;
Second step: more described first sawtooth signal and one second voltage produce a secondary signal;
Third step: switch described first sawtooth signal, first voltage or second voltage to one end points according to described first and second signal, on described end points, to produce one the 3rd signal;
The 4th step: more described the 3rd signal and one first input signal produce one first pulse-width modulation signal;
The 5th step: produce the First Five-Year Plan signal according to one the 4th signal and the described first pulse-width modulation signal, described the 4th signal be described first and second signal one of them;
The 6th step: relatively one second sawtooth signal and a tertiary voltage produce one the 6th signal;
The 7th step: more described second sawtooth signal and one the 4th voltage produce one the 7th signal;
The 8th step: switch described second sawtooth signal, tertiary voltage or the 4th voltage to one end points according to the described the 6th and the 7th signal, on described end points, to produce one the 8th signal;
The 9th step: more described the 8th signal and one second input signal produce one second pulse-width modulation signal;
The tenth step: produce 1 the tenth signal according to one the 9th signal and the described second pulse-width modulation signal, described the 9th signal be the described the 6th and the 7th signal one of them;
The 11 step: according to the load of the described the 5th and the tenth signal driving in described D class A amplifier A output.
27. control method as claimed in claim 26 is characterized in that, the waveform of described the 3rd signal is an irregular quadrilateral.
28. control method as claimed in claim 26 is characterized in that, the waveform of described the 8th signal is an irregular quadrilateral.
29. control method as claimed in claim 26 is characterized in that, more comprises regulating described first voltage to change the pulse duration of described first signal.
30. control method as claimed in claim 26 is characterized in that, more comprises regulating described second voltage to change the pulse duration of described secondary signal.
31. control method as claimed in claim 26 is characterized in that, more comprises regulating described tertiary voltage to change the pulse duration of described the 6th signal.
32. control method as claimed in claim 26 is characterized in that, more comprises regulating described the 4th voltage to change the pulse duration of described the 7th signal.
33. control method as claimed in claim 26 is characterized in that, more comprises:
During greater than the amplitude of described the 3rd signal, detect the error amount between described the 5th signal and the described first pulse-width modulation signal at the amplitude of described first input signal;
Postpone described second sawtooth signal according to described error amount.
34. control method as claimed in claim 26 is characterized in that, more comprises:
Control discharging and recharging of an electric capacity to produce described second sawtooth signal;
Stop discharging and recharging according to described the 5th signal and the first pulse-width modulation signal to described electric capacity to postpone described second sawtooth signal.
35. control method as claimed in claim 34, it is characterized in that, describedly stop the step that discharges and recharges to described electric capacity according to described the 5th signal and the first pulse-width modulation signal and comprise and stop discharging and recharging when described the 5th signal and the described first pulse-width modulation signal inversion described electric capacity.
36. control method as claimed in claim 34 is characterized in that, more comprises:
More described second sawtooth signal and one first reference voltage produce one first comparison signal;
More described second sawtooth signal and one second reference voltage produce one second comparison signal;
Adjust the capacitance of described electric capacity with described first and second comparison signal.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200810169462 CN101729030B (en) | 2008-10-20 | 2008-10-20 | D class amplifier and control method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 200810169462 CN101729030B (en) | 2008-10-20 | 2008-10-20 | D class amplifier and control method thereof |
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| CN101729030A true CN101729030A (en) | 2010-06-09 |
| CN101729030B CN101729030B (en) | 2013-09-11 |
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| CN 200810169462 Expired - Fee Related CN101729030B (en) | 2008-10-20 | 2008-10-20 | D class amplifier and control method thereof |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117714A (en) * | 2011-11-14 | 2013-05-22 | 联发科技股份有限公司 | Audio amplifier |
| CN105305799A (en) * | 2015-11-13 | 2016-02-03 | 四川长虹电器股份有限公司 | Narrow pulse limit control method for variable frequency controller |
| CN107528551A (en) * | 2016-06-22 | 2017-12-29 | 联咏科技股份有限公司 | Electric current bootstrapping comparator and operational amplifier |
| CN112886933A (en) * | 2021-01-13 | 2021-06-01 | 上海艾为电子技术股份有限公司 | Class D audio amplifier, adaptive pulse width adjusting method thereof and electronic equipment |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101485082B (en) * | 2006-07-07 | 2013-06-19 | Nxp股份有限公司 | Class d audio amplifier |
| CN201018655Y (en) * | 2006-12-01 | 2008-02-06 | 普诚科技股份有限公司 | Loudspeaker system of using pulsewidth modulation signal to save power consumption |
| CN100471044C (en) * | 2007-03-08 | 2009-03-18 | 埃派克森微电子(上海)有限公司 | Frequency switching circuit for restraining the D power amplifier POP sound and its method |
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2008
- 2008-10-20 CN CN 200810169462 patent/CN101729030B/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103117714A (en) * | 2011-11-14 | 2013-05-22 | 联发科技股份有限公司 | Audio amplifier |
| US9319003B2 (en) | 2011-11-14 | 2016-04-19 | Mediatek Inc. | Audio amplifier |
| CN103117714B (en) * | 2011-11-14 | 2016-05-04 | 联发科技股份有限公司 | Amplifier |
| CN105305799A (en) * | 2015-11-13 | 2016-02-03 | 四川长虹电器股份有限公司 | Narrow pulse limit control method for variable frequency controller |
| CN107528551A (en) * | 2016-06-22 | 2017-12-29 | 联咏科技股份有限公司 | Electric current bootstrapping comparator and operational amplifier |
| CN112886933A (en) * | 2021-01-13 | 2021-06-01 | 上海艾为电子技术股份有限公司 | Class D audio amplifier, adaptive pulse width adjusting method thereof and electronic equipment |
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| CN101729030B (en) | 2013-09-11 |
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