CN102332869B - High-integration BTL (bridge-tied load) audio power amplifier - Google Patents
High-integration BTL (bridge-tied load) audio power amplifier Download PDFInfo
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- CN102332869B CN102332869B CN201110155195.3A CN201110155195A CN102332869B CN 102332869 B CN102332869 B CN 102332869B CN 201110155195 A CN201110155195 A CN 201110155195A CN 102332869 B CN102332869 B CN 102332869B
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Abstract
The invention discloses a high-integration BTL (bridge-tied load) audio power amplifier. The high-integration BTL audio power amplifier comprises four amplifiers and two transconductance amplifiers as well as a first resistor to a ninth resistor, an interior compensation capacitor, and a standard current module, wherein the first and the second amplifiers provide a main access and used as an upper and a lower drive units as the audio power amplifier, the third and the fourth amplifiers and the first transconductance amplifier and the fifth to the eighth resistors together form an output imbalance compensation module, the first transconductance amplifier is in charge of detecting direct-current common mode imbalance at two ends of a BTL and feeding back to a current control end for finely regulating current to further reduce imbalance, and can also be used for finely regulating gains when outputting clip waves so that the gains at two output ends are completely same, the output power reaches the maximum, and the efficiency is highest; the standard current module is in charge of providing accurate output midpoint for the output end of the first transconductance amplifier, and the second transconductance amplifier is in charge of providing frequency compensation of a system except for Miller compensation, and provides enough phase margin for the system.
Description
Technical field
The present invention relates to a kind of audio power amplifying circuit, particularly the offset compensation in BTL application audio frequency power amplifier, gain compensation, and phase compensation.
Background technology
Under same voltage, in order to obtain higher sound output, capital adopts the BTL mode to apply, a kind of popular usage as shown in Figure 1, this usage has been saved output coupling capacitor, also reduce outside dividing potential drop consumption, but this usage has two shortcomings: there is no the offset compensation circuit, output outside need building-out capacitor, the BTL application requires high especially to the offset voltage of circuit output end, if imbalance is dealt with improperly, can affect quiescent dissipation on the contrary, also can produce very large current sound, when large-signal output slicing, if the two ends gain has difference, can affect whole delivery efficiency, when BTL applies in addition, circuit makes circuit more unstable than the monophony application, and phase margin diminishes, and general settling mode is the electric capacity of external 100nF, but the present invention improves internal structure, without any building-out capacitor in outside.
Summary of the invention
technical problem: the present invention mainly solves BTL imbalance and gain inconsistence problems, and the circuit stability problem.
technical scheme:
A kind of high integration BTL audio-frequency power amplifier, comprise 4 amplifier AMP, 2 trsanscondutance amplifiers and the first to the 9th resistance, internal compensation electric capacity, reference current module, wherein the first amplifier, the second amplifier are main amplifier, primary path is provided, described the 3rd amplifier, the 4th amplifier, the first trsanscondutance amplifier, the 5th to the 8th resistance form output offset compensation module jointly, and the 3rd amplifier, the 4th amplifier are respectively the driver elements up and down of audio-frequency power amplifier simultaneously;
The first trsanscondutance amplifier, be responsible for detecting the direct current common mode imbalance of BTL two ends, feed back to current controling end inching electric current, and then reduce to lack of proper care, simultaneously also fine setting gain when the output slicing of the first trsanscondutance amplifier, make to export the two ends gain identical, makes power output reach maximum, most effective, the reference current module is responsible for the first trsanscondutance amplifier output and provides and export accurately mid point; The second trsanscondutance amplifier is responsible for providing the frequency compensation of the system except miller-compensated, and its equivalent capacitance is 100nF, for system provides enough phase margins;
Wherein: the positive termination reference voltage signal of the first amplifier, the negative terminal of the first amplifier is connected with an end of the first resistance, an end of the second resistance respectively; The anode of output termination the 3rd amplifier of the first amplifier;
The other end of described the first resistance is connected with an end of the 3rd resistance, the 4th resistance respectively, the other end of the 3rd resistance is connected with the negative terminal of the second amplifier, the positive termination reference voltage signal of the second amplifier, the anode of output termination the 4th amplifier of the second amplifier;
The output of described the 3rd amplifier respectively with the other end of an end of the 5th resistance, the second resistance, be connected; The other end of the 5th resistance is connected with the negative terminal of the 3rd amplifier, an end of the 6th resistance respectively; The other end of described the 6th resistance is connected with an end of the 8th resistance, the anode of the first trsanscondutance amplifier respectively;
The other end of described the 8th resistance is connected with the negative terminal of the 4th amplifier, an end of the 7th resistance respectively; The output of described the 4th amplifier is connected with the other end of the 7th resistance, the other end of the 4th resistance respectively;
The negative terminal of described the first trsanscondutance amplifier connects the midpoint potential signal, and the output of the first trsanscondutance amplifier connects an end of the 9th resistance, the negative terminal of the second trsanscondutance amplifier, the output of the second trsanscondutance amplifier; The anode of described the second trsanscondutance amplifier connects respectively the other end of the 9th resistance, an end of internal compensation electric capacity, the other end ground connection of internal compensation electric capacity.
beneficial effect: owing to having adopted the offset compensation network, circuit is with the fluctuation of technique, imbalance obviously reduces, dispersion degree also reduces greatly, there is no the circuit of this compensating network, on delivery efficiency, also improves, due to integrated 104 necessary electric capacity of BTL, make peripheral the simplification, apply simplyr, system is more stable.
The accompanying drawing explanation
Fig. 1 is general BTL functional block diagram.Figure comprises: the first operational amplifier A, the second operational amplifier B.
Fig. 2 is to be band offset compensation and frequency compensated block diagram.
Figure comprises: the first operational amplifier A, the second operational amplifier B, the 3rd operational amplifier C, four-operational amplifier D, the 5th trsanscondutance amplifier E, the 6th trsanscondutance amplifier F.
Embodiment
Utilized six amplifiers in the present invention, wherein the first operational amplifier A, the second operational amplifier B determine the gain of primary path, the closed loop gain of BTL
GV={1+R2/ (R1+R3) }+R4/ (R1+R3) }+Σ GV(correction); , in order to make up the fluctuation of technique, must be arranged to wherein R2=R4, R1=R3; If gain when inconsistent in two amplifiers, just there will be the common mode imbalance, depart from mid point, compensating circuit can start, and adjusts the gain compensation electric current, and the amplifier of the first slicing of suitable reduction makes the two-way gain in full accord.
The common mode imbalance, circuit itself is provided with a reference current i0=(VCC-2Vref)/R2, suppose full symmetric, do not have under the prerequisite of balanced electric current, reference current is divided equally by the first operational amplifier A, the second operational amplifier B, the resistance R of flowing through in the first operational amplifier A 2 electric currents equal in the second operational amplifier B the to flow through electric current of resistance R 4, so the voltage of the first operational amplifier A output mid point is:
i0*R2/2+Vref=Vref+VCC/2-Vref=VCC/2
The purpose that Vref is set is the maximum input level born in order to improve input.
In like manner the voltage of the output mid point of the second operational amplifier B is also VCC/2.
In reality, there are the common mode imbalance in the first operational amplifier A, the second operational amplifier B, the 3rd operational amplifier C, four-operational amplifier D are responsible for detecting imbalance, when output gain does not mate, vo voltage deviation mid point, start the offset compensation circuit, the output offset current, and then adjust gain passage bigger than normal, make the gain of two-way output suitable; When technological fluctuation causes the output common mode imbalance, the offset compensation module starts, and the output corrective current is adjusted the output mid point, reaches the effect of correcting static imbalance.The 3rd operational amplifier C, four-operational amplifier D are simple closed loop application amplifiers, and gain is set to 3; Owing to being arranged on output driving part, also playing the THD that reduces output, and then reduce the whole distortion factor.
Due to what adopt, it is the BTL application, two system A that work independently, B, combine, needed frequency compensation is more complicated, the compensation point that the present invention selects, from whole system, suppose input end grounding, compensation point is the interchange ground of system, if system is powering on, or other interference makes the first operational amplifier A, there is the high frequency imbalance in the second operational amplifier B output, there is disturbing pulse in compensation point so, owing to being the BTL application, this disturbs through the first operational amplifier A, the feedback of the second operational amplifier B is sustained, form concussion, this concussion will be sustained, form self-excitation.This phenomenon is not general phase compensation theory,
Because the frequency compensation of the first operational amplifier A, the second operational amplifier B self is no problem, work independently highly stable, but be combined into the BTL application, for stablizing of system, need again extra setting compensation network.The present invention arranges one to earth capacitance at compensation point, as high-frequency ac ground, makes the high frequency waves of the first operational amplifier A, the second operational amplifier B output directly through building-out capacitor, arrive ground after feedback, and the primary path of not flowing through, can not form positive feedback.Prevent high-frequency self-excitation.Below derive and how to realize 100nF electric capacity.
Suppose that the electric current flowed into is i, port voltage is v, and the resistance both end voltage is VR; To earth capacitance, be c, equiva lent impedance is rin; The equivalence equivalent capacity is cin; The mutual conductance of gm trsanscondutance amplifier is the first operational amplifier A; Meet following relational expression:
i=VR*A+VR/R（1）
v=VR/jωc*R?+VR(2)
Can draw rin=ri+cin=1/A*R+1/ j ω c*R*A(3 by (1), (2)), isoboles is as shown in Figure 3.
Ri=1/A*R wherein; Cin=1/j ω c*R*A; Ri ≈ 0, equivalent capacity cin=(A*R) 1/j ω c, so equivalent capacity has been amplified (A*R) doubly; Suppose that mutual conductance is A=10, R=10K, inner integrated capacitance c=1pF, so cin=(10*10k*1p) F=100nF; Utilize smaller capacitive, realized the function of large electric capacity, eliminated high-frequency self-excitation.
Claims (1)
1. a high integration BTL audio-frequency power amplifier, it is characterized in that: comprise first to fourth amplifier AMP(A, B, C, D), the first to second trsanscondutance amplifier (E, F) and the first to the 9th resistance (R1～R9), internal compensation electric capacity (C1), the reference current module, the first amplifier (A) wherein, the second amplifier (B) is main amplifier, primary path is provided, described the 3rd amplifier (C), the 4th amplifier (D), the first trsanscondutance amplifier (E), the common output offset compensation module that forms of the 5th to the 8th resistance (R5 ~ R8), while the 3rd amplifier (C), the 4th amplifier (D) is respectively the driver element up and down of audio-frequency power amplifier,
The first trsanscondutance amplifier (E), be responsible for detecting the direct current common mode imbalance of BTL two ends, feed back to current controling end inching electric current, and then reduce to lack of proper care, simultaneously also fine setting gain when the output slicing of the first trsanscondutance amplifier (E), make to export the two ends gain identical, makes power output reach maximum, most effective, the reference current module is responsible for the first trsanscondutance amplifier (E) output and provides and export accurately mid point; The second trsanscondutance amplifier (F) is responsible for providing the frequency compensation of the system except miller-compensated, and its equivalent capacitance is 100nF, for system provides enough phase margins;
Wherein: the positive termination reference voltage signal (Vref) of the first amplifier (A), the negative terminal of the first amplifier (A) is connected with an end of the first resistance (R1), an end of the second resistance (R2) respectively; The anode of output termination the 3rd amplifier (C) of the first amplifier (A);
The other end of described the first resistance (R1) is connected with an end of the 3rd resistance (R3), the 4th resistance (R4) respectively, the other end of the 3rd resistance (R3) is connected with the negative terminal of the second amplifier (B), the positive termination reference voltage signal (Vref) of the second amplifier (B), the anode of output termination the 4th amplifier (D) of the second amplifier (B);
The output of described the 3rd amplifier (C) is connected with an end of the 5th resistance (R5), the other end of the second resistance (R2) respectively; The other end of the 5th resistance (R5) is connected with the negative terminal of the 3rd amplifier (C), an end of the 6th resistance (R6) respectively; The other end of described the 6th resistance (R6) is connected with an end of the 8th resistance (R8), the anode of the first trsanscondutance amplifier (E) respectively;
The other end of described the 8th resistance (R8) is connected with the negative terminal of the 4th amplifier (D), an end of the 7th resistance (R7) respectively; The output of described the 4th amplifier (D) is connected with the other end of the 7th resistance (R7), the other end of the 4th resistance (R4) respectively;
The negative terminal of described the first trsanscondutance amplifier (E) connects the midpoint potential signal, and the output of the first trsanscondutance amplifier (E) connects an end of the 9th resistance (R9), the negative terminal of the second trsanscondutance amplifier (F), the output of the second trsanscondutance amplifier (F); The anode of described the second trsanscondutance amplifier (F) connects respectively the other end of the 9th resistance (R9), an end of internal compensation electric capacity (C1), the other end ground connection of internal compensation electric capacity (C1).
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| CN201110155195.3A CN102332869B (en) | 2011-06-10 | 2011-06-10 | High-integration BTL (bridge-tied load) audio power amplifier |
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| CN201110155195.3A CN102332869B (en) | 2011-06-10 | 2011-06-10 | High-integration BTL (bridge-tied load) audio power amplifier |
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| TWI473000B (en) * | 2012-03-12 | 2015-02-11 | Egalax Empia Technology Inc | Signal sensing circuit |
| CN102710226B (en) * | 2012-05-29 | 2015-04-29 | 上海艾为电子技术股份有限公司 | Power amplifying device |
| CN103490616B (en) * | 2013-07-05 | 2016-01-20 | 西安启芯微电子有限公司 | Current-mode DC-DC converter |
| CN103475214A (en) * | 2013-09-06 | 2013-12-25 | 成都芯源系统有限公司 | Switch converter and control circuit and control method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1582527A (en) * | 2001-11-07 | 2005-02-16 | 皇家飞利浦电子股份有限公司 | Power amplifier module with distortion compensation |
| CN101217263A (en) * | 2008-01-17 | 2008-07-09 | 埃派克森微电子有限公司 | A compensatory method and device for DC offset voltage of amplifier |
| JP4166694B2 (en) * | 2001-09-04 | 2008-10-15 | アナログ デバイセス インコーポレーテッド | Ping-pong amplifier with automatic zeroing and chopping |
-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4166694B2 (en) * | 2001-09-04 | 2008-10-15 | アナログ デバイセス インコーポレーテッド | Ping-pong amplifier with automatic zeroing and chopping |
| CN1582527A (en) * | 2001-11-07 | 2005-02-16 | 皇家飞利浦电子股份有限公司 | Power amplifier module with distortion compensation |
| CN101217263A (en) * | 2008-01-17 | 2008-07-09 | 埃派克森微电子有限公司 | A compensatory method and device for DC offset voltage of amplifier |
Non-Patent Citations (2)
| Title |
|---|
| 一种BTL低静态功耗CMOS音频功率放大器的设计;汪少康等;《电子器件》;20080430;第31卷(第2期);472-475 * |
| 汪少康等.一种BTL低静态功耗CMOS音频功率放大器的设计.《电子器件》.2008,第31卷(第2期),472-475. |
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