TWM365019U - Distortion-suppressed D-type power amplifier - Google Patents

Description

.M365019 V. New Description: [New Technology Area] This creation is about an audio amplifier, especially a Class D audio amplifier with distortion suppression. [Prior Art] Audio amplifier is an important device for driving speakers. Common audio amplifiers include Class AB audio amplifiers and 〇 class audio amplifiers. Among them, D φ class audio amplifiers are more efficient than Class AB audio amplifiers. Two to five times, and the power and power consumption required for Class D amplifiers is significantly reduced compared to Class AB audio amplifiers. Class D amplifiers mainly use pwm (Pulse Width Modulation) modulation technology to convert the input audio signal into a switching control signal, thereby controlling the conduction and shutdown of the power electronic components to achieve the purpose of amplifying the audio signal. However, the output audio signal amplified by the class D amplifier also includes the modulated high frequency harmonics. Therefore, at the output end of the class D amplifier, a low pass filter is required to filter out the high frequency harmonics. The wave component, after restoring the waveform of the audio signal, sends the signal to the speaker for playback. However, since the low-pass filter is often an LC filter, the size and circuit cost of the class D amplifier are increased. Therefore, the filterless class 〇 Power amplifier is also being researched and developed. As shown in the first figure, it is a circuit structure diagram of a D-type power amplifier without a wave-wave circuit of the prior art, / M365019 Filterless Circuit Class D Power Amplifier 500 has an input amplifier 502; - Error Amplifying Unit 503; - First and Second Reference Wave Generators 5 04, 505; - First and Second Comparators 506, 507 ; - gate drive circuit 5 08; - output stage field effect transistor unit 509; and a feedback unit 513. • An audio signal 501 is input to the negative input terminal of the input amplifier 502 via an input capacitor CIN5. The input amplifier 502 preamplifies the audio signal 501, and transmits a preamplified audio signal through an integrator resistor R51 φ. The error amplifying unit 503 is input, that is, the negative input terminal of an integrator 503 1 , and the integrator 503 1 is coupled to the integrator resistor R5 1 and an integrator capacitor C51, and the error amplifying unit 503 is amplified. After the preamplified audio signal, the §fl number is input to the positive input terminals of the first comparator 506 and the second comparator 507. The first comparator 506 and the negative input end of the second comparator 507 are respectively coupled to the first reference wave generator 5〇4 and the second reference wave generator 5〇5, and the first reference wave generator 5〇4 And the second reference wave generator 5〇5# generates a reference wave and a second reference wave, and compares the audio signal with the reference wave, the first comparator 5〇6 and the second comparator 5〇7 A pulse modulation signal is respectively outputted to the gate driving circuit 5〇8, and the gate driving circuit 508 can control the switch of the output stage field effect unit 509 which is usually composed of a power transistor, respectively. The positive output terminal (Quip) and the negative output terminal (OUTN) of the amplifier output audio signals to a speaker 5n, and the feedback audio gain is fed back by the feedback amplifier 5131 and the feedback resistors (RFB1, RFB2, RFB3). size. 4 M365019 The above-mentioned filterless circuit class D power can effectively turn the audio sfl number to the speaker from a lun, and also responds to the input audio signal by a 楮田口杈, but still has many shortcomings and shortcomings: The feedback unit lacks the design of controllable gain. Although it can input the audio signal back to the library, it can't control the audio distortion caused by the excessive audio gain. For example, second, you are a well-known technology. The class D power amplification of the filterless circuit is crying. . The output waveform diagram, where the double arrow is indicated in the figure, is the positive output (〇υτρ) output high level and negative output ((10)ΤΝ) output low level, or the negative output (Xie ν) output south The level and the positive output (〇υτρ) output a low level, because the frequency received by the speaker is the positive output signal minus the negative output, the value of the signal 'is therefore relative to the ancient one' The inter-level audio signal loses the relatively low-level audio signal and the audio signal received by the lower and lower % audio is very likely to be distorted due to excessive gain. 2. The two-stage amplified audio signal composed of the input amplifier and the error amplifier is a two-stage amplified audio signal, which is complicated and 'is easy to cause the front-end output signal to the latter stage' and causes the GateDelay phenomenon. That is, there is a possibility that the audio is distorted due to the delay of the gate. Therefore, the creators of this case, in view of the implied lack of the class C power amplifier of the chopper-free circuit, have made great efforts to improve and innovate, and finally developed a class of power amplifiers for distortion suppression of the present invention. M365019 [New Content] The main purpose of this creation is to provide a Class D function of distortion suppression = Amplifier 'Using Simple Logic Application' to monitor output audio and prevent audio signal distortion to maintain high quality output of the speaker . • The second objective of this creation is to provide a Class D power stand that is out of direct buckle suppression, combined with a differential amplifier and a variable resistor to efficiently amplify the audio signal and prevent the delay due to the brake delay. The current distortion of the audio distortion type D power amplifier ^ 匕牯 gain control early 7C, a first - pulse modulation single. - early, a first pulse modulation unit; first-class control unit; The level control is early 70, the level control unit has a type of flip-flop and at least - anti-mutual or logic, the output end of the D-type is connected to the gain control unit, and the type is positive The R end of the counter is connected to the output of the $ or Logic gate. When the distortion is suppressed, the Class D power amplification is crying — r 〇 positive output (〇 ut) and negative output End (Outb) 'At the same time, the turn of the ancient M Hu output level and the bottom level signal to the anti-mutation or logic gate, the anti-mutual or logical fly-out output level signal to the D-type positive; 5, The D-type flip-flop is then sent back to the gain control unit to control the gain control. Billing - the effect of the truth. ^Weigh down the audio gain to achieve the suppression of audio loss. [Embodiment In order to be able to describe the distortion suppression 6 M365019 class D power amplifier proposed in this creation, the following will be explained in detail with the diagram. Please refer to the third and fourth figures, which is a circuit structure diagram of a distortion-suppressed class D power amplifier of the present invention, and a circuit structure diagram of a fully differential amplifier of a distortion-suppressed class D power amplifier of the present invention. A distortion-inhibiting class D power amplifier 1 has a positive output terminal (〇ut) and a negative wheel output terminal (Outb) to drive a speaker 512, including:

A gain control unit 2 includes a fully differential operational amplifier (FuUy differential OPA) 21 having a positive input terminal (vin+) and a negative input terminal (Vin_), and a positive output The terminal (vout+) and a negative output terminal (v〇ut_), the positive input terminal and the negative input terminal of the fully differential operational amplifier η are coupled to an audio signal 5〇1, and after the audio signal 501 is amplified From the positive output terminal and the negative output terminal, an amplified audio signal is rotated through a resistor R16 and a resistor R17 to the second pulse modulation unit 4 of the next stage; a first variable resistor Rlv is coupled to Between the positive input terminal (Vin+) and the negative output terminal (V0ut-) of the fully differential operational amplifier 21, the hunting is adjusted by the resistance value of the first variable resistor Rv丨, and the fully variable operational amplifier 21 can be adjusted. The gain of the amplified audio signal outputted by the negative output terminal; and a second variable resistor RV2, which is connected to the negative terminal of the positive terminal (vin_) of the fully differential operational amplifier 21 ( Between Vout+), by adjusting the second variable resistor The gain of the audio signal of the fully differential op amp; the amplification of the output of the positive output of 21. M365019 The two-pulse modulation unit 4, please refer to the fifth figure, which is the pulse modulation of a class D power amplifier with distortion suppression. The circuit structure diagram of the variable unit includes a reference wave generator 41 and a comparator 42 having a positive input terminal, a negative input terminal, and an output terminal, and the negative input terminal of the comparator 42 The reference wave generator 41 is coupled to receive a reference wave signal generated by the reference wave generator 41. In this embodiment, two sets of pulse modulation units 4 are used, which respectively consume the fully differential operational amplifier. The negative output terminal (V〇ut.) and the positive output terminal (v〇ut+), therefore, the positive input terminal of the comparator 42 of the group of pulse modulation unit 4 is transmitted through the resistor. The negative output terminal (v_) of the operational amplifier 21, and the positive input terminal of the comparator 42 of the other-group pulse modulation unit is transmitted through the resistor R17: connected to the positive output terminal of the fully differential operational amplifier 21 (v_+) ) to: receive the positive of the fully differential operational amplifier 21 Output terminal and negative output terminal • Raw two: the amplified audio signal, in addition, the second reference wave generator 41 generates an inversion phase to facilitate the comparator 42 for the fully differential carrier, the positive output of r 21 The amplified audio signal output from the end and the negative wheel output is 1::: When the level of the amplified audio signal is higher than the reference wave signal, the 42 round 1: the quasi-output is still the pulse modulation signal, and vice versa. The pulse modulation signal of the position of the device is changed to the position of the VCO. The type 8 M365019 power field effect transistor QN and a grounded p-type power field effect transistor Qp are respectively connected to the field effect transistor driving unit & 6, the field effect transistor driving unit 6 receives the pulse modulation unit 4 output pulse modulation (four), and based on the pulse modulation signal to control the on and off of the output stage field effect transistor group 7 to drive the speaker 512; /, - level control unit 8, including at least one D Type positive and negative (four), the D-type flip-flop 81 has a terminal, _ck terminal, a q terminal, - terminal, A Μ-. 'The ID end and the 'end end are the input end, and the Q end and the Qb end are the output end, and the D end of the d-type flip-flop Μ is connected to a real Vrr of the Vrr + Azhuo DC Signal, and its CK end

Coupled with a clock signal (Cl0ck), the Q terminal of the D inverse 81 is coupled to the add-on control unit 2... the Qb end is floating and at least - anti-mutual or logical ^Xn〇r) 82 R) 82 The anti-mutual or logic gate 82 has two input terminals and one round output, and the one of the input terminals of the anti-mutation or logic switch 82 is respectively coupled to the positive output terminal of the greatly suppressed class D power amplifier. (〇ut) 盥 It should be lost to + mountain

, Outb, Anti-mutual or Logic The output of the 82 is coupled to the D of the D-spoken 81. Please refer to the sixth.

, a level control unit for a distortion-suppressed Class D power amplifier, # & 1 circuit structure diagram, in this embodiment, two sets of D-type flip-flops are connected in series

$山接#丨 ° ' Although the CK of the D-type flip-flop 81 receives the signal of the system clock >

Class power amplification is again, and the distortion suppression D is the positive output (〇ut) and the negative output (Outb) respectively. 9 M365019 Output n level (High) and - low level (L〇w The audio signal is given to the speaker 512. If the audio signal of the low level and the low level continues to output for more than one time, the audio signal received by the speaker 512 is distorted, and the anti-mutation or logic is 82. For the D-type power receiving distortion suppression, the high-level and low-level signals output by the positive output (0ut) and the negative output (Μ) of the amplifier are in accordance with the anti-mutation or logic idle response characteristics. The mutex or logic gate 82 will immediately output the high level signal to the R terminal of the D-type flip-flop 81, since the first _ έ θ η μ ^ , , , i the flip-flop 8 1 E) is coupled to the Vcc The DC high-level signal, therefore, according to the reaction characteristics of the D-type flip-flop, the first group D-type flip-flop 81 outputs the high-level signal to the second group d-type positive and negative m, the first group D-type positive The counter 81 outputs a high level signal to the unit 2' to control the gain control unit 2 to lower the audio gain, and to suppress the effect of the day frequency distortion. For the comparators and the second comparators 83, please refer to the circuit diagram of the class D power amplifier circuit of the distortion suppression of the level control unit of the sixth drawing B. In the present embodiment, the device 83 has The two inputs and the comparison X, the mountain, the output terminal 'the positive wheel of the comparator 83' are not coupled to the positive output and the negative output of the fully differential operational amplifier, the negative of the comparator 83, that is, the comparator 83 output Μ _ connection - reference electric dust VREF ' and ' & respectively, the first - variable resistance 盥 first - variable resistance, compare "3 function for the complete differential operation, 丄 k origin and The negative output is confirmed by the positive transmission of the mountain-king differential amplifier, and the result is returned to..., the heart "仃the initial distortion U first variable resistor and the second variable resistor, adjust the audio with 10 M365019 Gain. In addition, in the present embodiment, a current control unit is also included. The electric control unit 3 is connected to the two sets of pulse modulation units 4, and the current control unit 3 can generate a fixed current signal, and amplify the audio, 11 er * form a second-rate «signal, by adjusting the current modulation signal, the output power consumption of the power amplifier can be controlled to be reduced; and a plurality of resistors, the resistors R1 5, R1 8 are coupled to the power of the distortion suppression The positive output terminal (〇ut) and the negative output terminal (7) of the amplifier i are two: between the pulse modulation unit 疋4, which is the feedback resistor of the output, and the resistor phantom 6 ^ R17 is coupled to the pulse modulation unit 4 and the gain The control unit 2 is the input buffer resistor. System ❿ In summary, the author uses the D-type flip-flop and the anti-mutation or logic-closed to monitor the signal of the wheel end by using the output terminal and the gain control unit, and uses the feedback function to suppress the distortion of the audio signal. The distortion-suppressed Class D power amplifier of this creation has the following advantages over other conventional technologies: I. Innovative: Distortion-suppressed Class D power amplifier with simple anti-reverse: anti-mutation or logic gate The cooperation can instantly monitor whether the audio signal of the audio power amplifier is distorted or not, and the audio signal is out of straightness, and the gain of the round frequency of the wheel end can be found. Mode of sound

2. The distortion suppression D of this creation is based on the integrated M365019 兀 full differential amplifier as the audio signal preamplifier, using the resistance value of the variable resistor to adjust the gain of audio amplification. Compared with the conventional power amplifier system, which uses two-stage audio amplification, this creation uses only a one-integration type fully differential amplifier, which can avoid the delay of the front-end amplifier's output and input. Gate Delay) The phenomenon occurs. The above description is a detailed description of one of the possible embodiments of the present invention, but the embodiment is not intended to limit the scope of the patent, and equivalent implementations or modifications that are not departing from the spirit of the present invention should include In the scope of the patent in this case. [Simple diagram of the diagram] The first diagram is the circuit structure diagram of the filterless class D power amplifier of the prior art; the second diagram is the output waveform diagram of the filterless class D power amplifier of the prior art; The circuit structure diagram of the class D power amplifier of the distortion suppression of the present invention; the fourth figure is the circuit structure diagram of the fully differential operational amplifier of the class D power amplifier of the distortion suppression of the creation; A class D function of distortion suppression; a circuit of a pulse modulation unit of a large device 12 M365019 composition; a sixth figure A, a sixth figure B is a level control unit of a class D power amplifier of distortion suppression Circuit structure diagram. [Description of main component symbols] 1 Class D power amplifier with distortion suppression 2 Gain control unit 21 Fully differential operational amplifier 3 Current control unit 4 Pulse modulation unit 41 Comparator 42 Reference wave generator 6 Gate drive unit 7 Output stage field Effect transistor group 8 Level control unit 81 D-type flip-flop 82 Anti-mutation or logic gate (XNOR) 83 Comparator 500 Power amplifier without filter circuit 501 Audio signal 502 Input amplifier 503 Error amplification unit 13 M365019

503 1 integrator 504 first reference wave generator 505 second reference wave generator 506 first comparator 507 second comparator 508 gate drive circuit 509 output stage field effect transistor unit 5 12 speaker 5 13 feedback unit 5131 Feedback amplifier RFB1 ~ RFB3 resistor R51 resistor CIN5, C51 capacitor Q51 ~ Q54 field effect transistor R15 ~ R18 resistor RV1 first variable resistor RV2 second variable resistor QN N-type power field effect transistor QP P-type power field effect Transistor VREF reference voltage 14

Claims (1)

M365019 VI. Patent Application Park: K A Class-D power amplifier with distortion suppression, which has a positive (4) ((10)) and a negative output (0utb) to drive a speaker, including: Increase control unit, transfer - audio signal, · • to vm modulation unit, is connected to the gain control unit to receive the gain control unit to output one of the amplified audio signals, and generate a modulation signal; ° field effect electric Ba body drive unit, The system is coupled to the pulse modulation unit. The output stage field effect transistor group is connected to the field effect transistor driving the early field effect transistor driving unit to receive the pulse modulation signal rotated by the pulse modulation unit. And based on the pulse modulation signal to control the switch of the output stage field effect transistor group to drive the speaker; and, a level control unit, comprising: at least a D-type flip-flop having two inputs, The second output end and the R end (R-, the two input ends of the D-type flip-flop are respectively coupled to the high-level DC signal of the VCC, and the 'one-time pulse signal (1), and the D-type positive and negative The two output ends of the device are respectively connected to The control unit and the 'floating state of the line; and the two-two anti-mutual or logical (X job)' system have two rounds of input and one output, side anti-mutation or logic gate The input is coupled to the positive output of the Class D power amplifier of Qianzhen suppression ((4) the negative output of the fish (〇Utb), and the output of the anti-mutation or logic idle is 15 M365019 The R terminal of the D-type flip-flop A, Set) 'When the distortion-reduced D-type power amplifier has the positive-wheel output (〇Ut) and the negative output (Outb), the high-order output is simultaneously output. , t lgh) and the bottom level (Low) signal to the anti-mutation or logic gate two inputs and the jin or logic gate that outputs the high level signal to the D type |1: θ ^ , Λ > ° 51 positive and negative The device outputs a high-level signal to the gain control unit to control the early and lower audio gain by cutting the I to achieve the effect of suppressing audio distortion. 2. A class D power amplifier of the type of distortion suppression as described in the patent application scope includes: a current control unit 'connects the pulse modulation unit, the current control generates a fixed current signal' Amplifying the audio signal to form a current modulation signal; and a plurality of resistors coupled to the positive output M (〇Ut) and the negative output terminal (〇_) of the distortion-suppressed class D power amplifier and the pulse modulation system The feedback resistor for the output is connected to the pulse modulation unit and the gain control unit, and is a buffer resistor for the input. 3. As claimed in the patent application, the distortion control unit D power amplification, wherein the gain control unit comprises: a fully differential operational amplifier (Fully differential 0PA) having a positive input terminal (Vin+) and a negative Input (W), and - positive input: end (V squeak and 1 output (V_-), the ut ^ ^ of the fully differential nose amplifier and the negative input are switched to the tone class 16