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.
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
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.
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5. 评估板TPA2013D1EVM 电路图