基于TPA2015設計的高效D類音頻功率放大技術

本文介紹了TPA2015主要特性，功能方框圖，性能測試框圖以及差分和單端輸入典型應用方框圖，放大器評估板TPA2015D1主要指標，電路圖和材料清單。

TPA2015是TI公司的高效D類音頻功率放大器，采用電池跟蹤SpeakerGuard AGC技術，并集成了自適應的升壓轉換器，能增加低輸出功率的效率。3.6V電源時TPA2015能向8歐姆揚聲器提供2W功率，THD為6%，效率85%。工作電壓2.5V-5.2V，帶自動恢復的熱和短路保護，有三種增益設定：6 dB, 15.5 dB和20 dB，主要用在手機，PDA，GPS，手提電子學和揚聲器。

The TPA2015D1 is a high efficiency Class-D audio power amplifier with battery-tracking SpeakerGuard AGC technology and an integrated adaptive boost converter that enhances efficiency at low output power. It drives up to 2W into an 8 speaker (6% THD). With 85% typical efficiency, the TPA2015D1 helps extend battery life when playing audio.

The built-in boost converter generates a 5.5V supply voltage for the Class-D amplifier. This provides a louder audio output than a stand-alone amplifier directly connected to the battery. The SpeakerGuard^TM AGC adjusts the Class-D gain to limit battery current and prevent heavy clipping.

The TPA2015D1 has an integrated low-pass filter to improve the RF rejection and reduce DAC out-of-band noise, increasing the signal to noise ratio (SNR).

TPA2015主要特性：

Built-In SpeakerGuard? Automatic Gain Control (AGC)

with Enhanced Battery Tracking

Limits Battery Current Consumption

Prevents Audio Clipping

2 W into 8 Load From 3.6 V Supply (6% THD)

Integrated Adaptive Boost Converter

Increases Efficiency at Low Output Power

Low Quiescent Current of 1.7 mA from 3.6 V

Operates From 2.5 V to 5.2 V

Thermal and Short-Circuit Protection with Auto Recovery

Three Gain Settings: 6 dB, 15.5 dB, and 20 dB

Independent Control for Boost and Class-D

Pin-to-Pin Compatible with TPA2013D1

Available in 1.954 mm × 1.954 mm 16-ball WCSP Package

TPA2015應用：

Cell Phones, PDA, GPS

Portable Electronics and Speakers

圖1。TPA2015功能方框圖

圖2。TPA2015測試框圖

圖3。TPA2015差分輸入典型應用方框圖

圖4。TPA2015單端輸入典型應用方框圖

圖5。TPA2015采用外接輸入濾波器降低DAC帶外噪音

音頻功率放大器評估板TPA2015D1

The TPA2015D1 audio power amplifier evaluation module is a complete, stand-alone audio board. It contains the TPA2015D1 WCSP (YZH) Class-D audio power amplifier with an integrated boost converter. All components and the evaluation module are Pb-Free.

評估板TPA2015D1指標：


圖6。評估板TPA2015D1 EVM電路圖
評估板TPA2015D1 EVM材清單（BOM）：



圖7。評估板TPA2015D1 PCB布局圖