TI的單片無濾波器D類音頻功率放大器TPA2013D1能為各種便攜式應用提供恒定輸出功率，如個人導航設備、PDA、移動電話、便攜式媒體播放器以及手持式游戲機等。

        由于結合了 2.7W 的 D 類放大器與集成式升壓轉換器，整體效率達到 85%，用戶播放音樂或打電話時的熱損耗很小，從而有助于延長電池使用壽命。本文介紹TPA2013D1 D類放大器的主要性能,方框圖,以及在數碼相機中的應用電路圖和TPA2013D1評估板的電路圖與所用的元器件.

        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

圖1.器件的功能方框圖

                                           圖2.TPA2013D1和TPA2032D1組成立體聲放大器電路

         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.

                                                           圖3. 數碼相機的LED驅動器

        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.



                                                                               圖4.旁路電路

        TPA2013D1EVM Schematic

                                                            圖5. 評估板TPA2013D1EVM 電路圖

      下表是TPA2013D1EVM的元件列表: