TI的单片无滤波器D类音频功率放大器TPA2013D1能为各种便携式应用提供恒定输出功率，如个人导航设备、PDA、移动电话、便携式媒体播放器以及手持式游戏机等。

        由于结合了 2.7W 的 D 类放大器与集成式升压转换器，整体效率达到 85%，用户播放音乐或打电话时的热损耗很小，从而有助于延长电池使用寿命。本文介绍TPA2013D1 D类放大器的主要性能,方框图,以及在数码相机中的应用电路图和TPA2013D1评估板的电路图与所用的元器件.

        The TPA2013D1 is a high efficiency Class-D audio power amplifier with an integrated boost converter. It drives up to 2.7 W (10% THD+N) into a 4 ohm speaker. With 85% typical efficiency, the TPA2013D1 helps extend battery life when playing audio.

        The built-in boost converter generates the voltage rail for the Class-D amplifier. This provides a louder audio output than a stand-alone amplifier connected directly to the battery. It also maintains a consistent loudness, regardless of battery voltage. Additionally, the boost converter can be used to supply external devices.

        The TPA2013D1 has an integrated low pass filter to improve RF rejection and reduce out-of-band noise, increasing the signal to noise ratio (SNR). A built-in PLL synchronizes the boost converter and Class-D switching frequencies, thus eliminating beat frequencies and improving audio quality. All outputs are fully protected against shorts to ground, power supply, and output-to-output shorts.

        主要特性:

        High Efficiency Integrated Boost Converter (Over 90% Efficiency)
        2.2-W into an 8-ohm Load from a 3.6-V Supply
        2.7-W into an 4-ohm Load from a 3.6-V Supply
        Operates from 1.8 V to 5.5 V
        Efficient Class-D Prolongs Battery Life
        Independent Shutdown for Boost Converter and Class-D Amplifier
        Differential Inputs Reduce RF Common Noise
        Built-in INPUT Low Pass Filter Decreases RF and Out of Band Noise Sensitivity
        Synchronized Boost and Class-D Eliminates Beat Frequencies
        Thermal and Short-Circuit Protection
        Available in 2.275 mm x 2.275 mm 16-ball WCSP and 4 mm x 4 mm 20-Lead QFN Packages
        3 Selectable Gain Settings of 2 V/V, 6 V/V, and
        10 V/V
        APPLICATIONS
        Cell Phones
        PDA
        GPS
        Portable Electronics

图1.器件的功能方框图

                                           图2.TPA2013D1和TPA2032D1组成立体声放大器电路

         Use the boost converter of the TPA2013D1 as a power supply for the flash LED of a digital still camera. Use a microprocessor or other device or synchronize the flash to shutter sound that typically comes from the speaker of a digital still camera. Figure 33 shows a typical circuit for this application. LEDs, switches, and other components will vary by application.

                                                           图3. 数码相机的LED驱动器

        Bypass the boost converter to drive the Class-D amplifier directly from the battery. Place a Shottky diode between the SW pin and the VCCIN pin. Select a diode that has an average forward current rating of at least 1A, reverse breakdown voltage of 10 V or greater, and a forward voltage as small as possible. See Figure 34 for an example of a circuit designed to bypass the boost converter.

        Do not configure the circuit to bypass the boost converter if VDD is higher than VCC when the boost converter is enabled (SDb ≥ 1.3 V); VDD must be lower than VCC for proper operation. VDD may be set to any voltage within the recommended operating range when the boost converter is disabled (SDb ≤ 0.3V).

        Place a logic high on SDb to place the TPA2013D1 in boost mode. Place a logic low on SDb to place the TPA2013D1 in bypass mode.



                                                                               图4.旁路电路

        TPA2013D1EVM Schematic

                                                            图5. 评估板TPA2013D1EVM 电路图

      下表是TPA2013D1EVM的元件列表: