Infineon MA12040无滤波器高效音频放大器解决方案

infineon公司的MA12040是基于专有的多级开关技术的无滤波器高效音频功率放大器，支持宽工作电压，工作电压+4V到+18V（PVDD）和+5V（A/DVDD），允许使用在许多差分应用中。多级开关技术在工作时有非常低的功耗.MA12040具有嵌入数字管理方案，功率管理算法大大地调整开关频率和调制，以优化功率损耗和输出功率范围内的EMI，其4阶反馈回路保证了低失真和高PSRR.MA12040具有对DC，短路，超温和欠压状态的保护功能.18V PVDD时的空闲功耗小于100mW，1W时的效率大于79%（1kHz sine， 8Ω），满功率时的效率大于92%（1kHz sine， 8Ω），DNR大于107dB（A-w，rel.to 1% THD+N powerlevel），55μV输出综合噪音（A-w），高输出电平时的THD+N为0.003%.可选择的增益为（20dB/26dB），2x40W峰值输出功率（18V PVDD， RL = 4Ω，10% THD+N level），2x20W连续输出功率（RL = 8Ω at 18V，PMP4， 10% THD+N level，无散热器）。主要用在电池工作的扬声器，无西南和坞站扬声器，多房间系统，家庭影院和条形音响。本文介绍了MA12040主要特性，典型应用框图，MA12040参考板主要特性，电路图，材料清单和PCB设计图。

The MA12040 is a super-efficient audio power amplifierbased on proprietary mulTI-level switching technology.It supports a wide supply voltage range， allowing it tobe used in many different applicaTIons.

MulTI-level switching enables very low power lossduring operaTIon. In addition， it allows the amplifier tobe used in filterless configurations at full rated powerin a wide range of audio products.

The MA12040 features an embedded digital powermanagement scheme. The power managementalgorithm dynamically adjusts switching frequency andmodulation to optimize power loss and EMI across theoutput power range.A 4th order feedback loop ensures low distortion and ahigh PSRR.

The MA12040 operates from a single power stagesupply voltage （PVDD） and a 5V system supply voltage（DVDD， AVDD）.Highly flexible output stage configurations are offered，ranging from four single-ended outputs to a singleparallel-BTL output.

The MA12040 features protection against DC， shortcircuits，over-temperature and under-voltagesituations.Flexible “Power Mode Profiles” allow the user to utilizethe multi-level switching technique for very low powerloss or very high audio performance.Device configuration is controlled through an I2Cinterface as well as dedicated control pins.

MA12040主要特性：

• Proprietary Multi-level Switching Technology

◦ 3-level and 5-level modulation

◦ Low EMI emission

◦ Filterless amplification

◦ Digital Power Management Algorithm

• High Power Efficiency （PMP4）

◦ 《100mW Idle power dissipation （18V PVDD，all channels switching）

◦ 》79% Efficiency at 1W power （1kHz sine， 8Ω）

◦ 》92% Efficiency at Full Power （1kHz sine， 8Ω）

• Audio Performance （PMP2）

◦ 》107dB DNR （A-w， rel. to 1% THD+N powerlevel）

◦ 55μV output integrated noise （A-w）

◦ 0.003% THD+N at high output levels

• 4th Order Feedback Error Control

◦ High suppression of supply disturbance

◦ HD audio quality

• Supply Voltages： +4V to +18V （PVDD） and +5V（A/DVDD）

• Selectable Gain （20dB/26dB）

• 2×40W peak output power （18V PVDD， RL = 4Ω，10% THD+N level）

• 2×20W continuous output power （RL = 8Ω at 18V，PMP4， 10% THD+N level， without heatsink）

• 2.0，2.1，4.0，1.0 Output Stage Configurations

• Protection

◦ Under-voltage-lockout

◦ Over-temperature warning/error

◦ Short-circuit/overload protection

◦ Power stage pin-to-pin short-circuit

◦ Error-reporting through serial interface （I2C）

◦ DC protection

• I2C control （four selectable addresses）

• Heatsink free operation with EPAD-down package

Package

• 64-pin QFN Package with exposed thermal pad（EPAD）

• Lead-free Soldering

MA12040应用：

• Battery Operated Speakers

• Wireless and Docking Speakers

• Soundbars

• Multiroom Systems

• Home Theater Systems

图1.MA12040典型应用框图

This application note describes the functionality and set-up of the reference design （Sections 2 and 3）。 It also includes a schematic， PCB layout， BOM and a discussion of circuit design considerations （Section 4）。 Measurement results （Section 5） show high performance in audio and efficiency parameters， as well as good thermal characteristics. Testing included a frequency sweep， output power sweep and electromagnetic interference tests. Finally， Appendix A provides sample code that demonstrates basic I2C communication using Arduino UNO.

The reference board （RFB） is a reference and demonstration board for Infineon’s MA12040， MA12040P， MA12070 and MA12070P amplifiers.

It contains a variety of digital/analog input， output and set-up/selection features. It also contains one on-board power supply （5 V buck converter）， so only one external power supply （PVDD） is necessary.

图2.MA12040参考板外形图

MA12040参考板主要特性：

The board can be used for evaluating or demonstrating key features/advantages of the MERUSTM Audio technology：

 Energy efficiency

− Power losses under normal user operating conditions （listening levels）

− Idle power loss

 Adaptive power management system

 No output filter components

− Solution cost and size reduction

 Audio performance

− THD performance and audio quality

 Fast product protyping

− All design files are available

− Guides as reference for product design-in

General board specifications

 Number of audio channels 2 x BTL or 1 x PBTL

 Audio input format：

o MA12040 and MA12070 Analog

o MA12040P and MA12070P Digital （I2S）

 Supply voltage range MA12040（P） 5 to 18 V

 Supply voltage range MA12070（P） 5 to 26 V

 Maximum output current per channel MA12040（P） 6 A

 Maximum output current per channel MA12070（P） 8 A

 Output power capability at 18 V PVDD：

o Peak 2 x 40 W sine 1 kHz （RMS） into 4 Ω （10 percent THD + N）

o Peak 2 x 20 W sine 1 kHz （RMS） into 8 Ω （10 percent THD + N）

o Continuous 2 x 9.0 W sine 1 kHz （RMS） into 4 Ω （less than 0.08 percent THD + N）

 Output power capability at 26 V PVDD：

o Peak 2 x 80 W sine 1 kHz （RMS） into 4 Ω （10 percent THD + N）

o Peak 2 x 40 W sine 1 kHz （RMS） into 8 Ω （10 percent THD + N）

o Continuous 2 x 9.0 W sine 1 kHz （RMS） into 4 Ω （less than 0.02 percent THD + N）

 Amplifier gain （MA12040 and MA12070 only） 20 dB or 26 dB （register configurable）

 Output integrated noise：

o MA12040 and MA12070 Less than 100 μVrms （AW）

o MA12040P and MA12070P Less than 150 μVrms （AW）

 Dynamic range：

o MA12040 and MA12070 More than 100 dB

o MA12040P and MA12070P More than 96 dB

 Idle current consumption at 18 V PVDD：

o MA12040 and MA12070 Less than 16 mA

o MA12040P and MA12070P Less than 19 mA

图3.MA12040参考板电路图

MA12040参考板材料清单：

图4.MA12040参考板PCB设计图（顶层）

图5.MA12040参考板PCB设计图（底层）