Low voltage high efficiency amplifier

Abstract

The utility model provides a low-voltage high-efficiency amplifier, which is characterized by comprising a pre-stage digital sound mixing amplifier, a power supply and a post-stage power amplifier, the pre-stage digital sound mixing amplifier inputs pre-stage signals, and then the pre-stage signals are amplified and subjected to volume / sound quality adjustment, and then the pre-stage signals enter the post-stage power amplifier; the post-stage power amplifier adopts a D-class amplifier chip to realize power amplification; the pre-stage digital audio mixing amplifier and the post-stage power amplifier are connected with a power supply for power supply, and the power supply adopts a switching power supply with AC90-110V wide power supply voltage range input to meet the requirements of the market on amplifiers which are high in efficiency, small in size and low in power supply voltage.

Description

Technical Field

[0001] The utility model relates to the field of amplifiers, in particular to a low-voltage high-efficiency amplifier. Background Art

[0002] Traditional audio power amplifiers, such as Class A and Class AB amplifiers, have good sound quality, but they are generally large and inefficient. Although Class A amplifiers have excellent sound quality, their efficiency is usually less than 20%, while Class AB amplifiers usually have an efficiency of no more than 40%. This means that during the operation of the amplifier, a large amount of electrical energy is converted into heat energy instead of audio output, which not only wastes energy, but also requires a larger heat sink to manage the generated heat. In addition, these amplifiers usually require high voltage power supply, such as 230VAC, which may not be convenient or safe in some application scenarios. Summary of the invention

[0003] In order to meet the market demand for an amplifier with high efficiency, small size and low voltage supply, the present invention proposes a low voltage and high efficiency amplifier.

[0004] The utility model realizes its technical purpose through a technical scheme: a low-voltage high-efficiency amplifier, comprising a front-stage digital mixing amplifier, a power supply, and a rear-stage power amplifier. The front-stage digital mixing amplifier enters the rear-stage power amplifier after amplification and volume / sound quality adjustment processing after the front-stage signal is input. The rear-stage power amplifier adopts a Class D amplifier chip to achieve power amplification. The front-stage digital mixing amplifier and the rear-stage power amplifier are connected to the power supply for power supply, and the power supply adopts a switching power supply with a wide power supply voltage range of AC90~110V input.

[0005] Furthermore, the power supply continuously outputs 1 / 8W of power, can meet the input of a wide power supply voltage range of AC90~110, the full power efficiency can reach 89%~90%, the power factor can reach above 0.8 at full power output, and the output voltage is 28V.

[0006] Furthermore, the post-stage power amplifier is also connected to a current limiting circuit, which is composed of an inductor, a capacitor, and a resistor. The current limiting circuit controls the output overheating and overcurrent protection of the class D amplifier chip.

[0007] Furthermore, the front-stage digital mixer amplifier supports multiple front-stage signal inputs, including AUX input and microphone input.

[0008] Furthermore, the post-stage power amplifier is composed of a TPA3118 series integrated class D amplifier chip.

[0009] The power supply range used in the utility model is upgraded from high voltage 230VAC input to low power supply voltage input (90V-110VAC), and the pre-stage signal is output to the post-stage after the volume / sound quality adjustment and limiting of the pre-stage digital mixer amplifier. The post-stage amplifier is a Class D power amplifier with 1 microphone and 2 background music (AUX) input ports. The overall efficiency ratio is increased from less than 40% of the previous Class AB to more than 65%, which can achieve the effect of small size and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments.

[0011] Attached Figure 1 This is a structural block diagram of a low-voltage, high-efficiency amplifier of the utility model.

[0012] Attached Figure 2 This is a block diagram of a low-voltage, high-efficiency amplifier pre-stage digital mixing amplifier of the utility model.

[0013] Attached Figure 3 This is a block diagram of a post-stage power amplifier of a low-voltage, high-efficiency amplifier of the utility model.

[0014] Attached Figure 4 This is a block diagram of a low voltage and high efficiency amplifier power supply according to the present utility model.

[0015] Attached Figure 5 This is a block diagram of a current limiting circuit for a low-voltage, high-efficiency amplifier of the utility model. DETAILED DESCRIPTION

[0016] The low voltage high efficiency amplifier of the utility model is further described below with reference to the accompanying drawings:

[0017] like Figure 1-4 The low-voltage high-efficiency amplifier shown includes a front-stage digital mixing amplifier, a power supply, and a post-stage power amplifier. The front-stage digital mixing amplifier receives a variety of front-stage signal inputs, including BGM (AUX input) and microphone input, and then enters the post-stage power amplifier after amplification and volume / sound quality adjustment processing; the front-stage digital mixing amplifier and the post-stage power amplifier are connected to the power supply for power supply, and the power supply adopts a switching power supply with an AC90~110V wide power supply voltage range input.

[0018] The power supply has a continuous output power of 1 / 8W, can meet the input of a wide power supply voltage range of AC90~110, the full power efficiency can reach 89%~90%, the power factor can reach above 0.8 at full power output, and the output voltage is 28V.

[0019] The front-stage digital mixer amplifier is composed of an amplifier circuit composed of a triode structure and a filter circuit to achieve amplification and volume / sound quality adjustment processing. The processed signal enters the input end of the rear-stage power amplifier through the output end for amplification.

[0020] The post-stage power amplifier is mainly composed of TI's TPA3118 series integrated Class D amplifier chip: dual-channel coupled output transformer 100V output mode (20W*1 full power) and controls the output overheating and overcurrent protection of the Class D amplifier chip through a current limiting circuit.

[0021] like Figure 5 As shown, the current limiting circuit is composed of inductors L1, L5, L6, capacitors and resistors. The inductors L5 and L6 are connected to the output end of the post-stage power amplifier. The inductors L5 and L6 are connected to the inductor L1, and are connected in parallel with resistors and capacitors, which are grounded.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Low voltage high efficiency amplifier, characterized by: The invention comprises a front-stage digital mixing amplifier, a power supply, and a rear-stage power amplifier. The front-stage digital mixing amplifier enters the rear-stage power amplifier after amplification and volume / sound quality adjustment processing after the front-stage signal is input. The rear-stage power amplifier adopts a Class D amplifier chip to realize power amplification. The front-stage digital mixing amplifier and the rear-stage power amplifier are connected to the power supply for power supply. The power supply adopts a switching power supply with a wide power supply voltage range of AC90~110V.

2. The low voltage high efficiency amplifier according to claim 1, characterized in that: The power supply continuously outputs power of 1 / 8W.

3. The low voltage high efficiency amplifier according to claim 1, characterized in that: The post-stage power amplifier is also connected to a current limiting circuit.

4. The low voltage high efficiency amplifier according to claim 1, characterized in that: The front-stage digital mixer amplifier supports multiple front-stage signal inputs, including AUX input and microphone input.

5. The low voltage high efficiency amplifier according to claim 1, characterized in that: The post-stage power amplifier is composed of TPA3118 series integrated class D amplifier chips.

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