这一款用到是2.8W 的立体功率放大器，因为是用的锂电池供电，电源电压只有3.3～4.2V ，所以这款是比较适合了，下面 是做原理图：
外围元件也是比较少的，又没有输出电容，来看一下他的参数：
- Fully Differential Architecture and High PSRR (-80 dB) Provide Excellent RF Rectification Immunity
- 2.8 W Into 3 From a 5-V Supply at THD = 10% (Typical)
- Very Low Crosstalk:
- -100 dB Typical at 5 V, 3
- 2.5-V to 5.5-V Operating Range
- Low Supply Current:
- 8 mA Typical at 5 V
- Shutdown Current: 80-nA Typical
- Fast Startup (27 ms) With Minimal Pop
- Internal Feedback Resistors Reduce Component Count
- Thermally Enhanced QFN Packaging
关机电流超小，刚好接上我这边的差分输出，来看看LAYOUT:
由于在量产的产品，不能说太多东西，QFN 封装：
做成产品所有性能指标都合格，SNR ,THD,PO 等。
