<div class="document"> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">本设计部分电路引用@winton 的《【课程设计】TPA3116+M18蓝牙数字功放》中电路。特此说明</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">一、描述</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">      1、功能描述</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">             1）、AUX音频输入+蓝牙 二合一输入，插入AUX自动切断蓝牙输入</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">             2）、TDA7492P13TR 是意法半导体生产的BTL 形式的D类音频功率放大器，输出功率可达25W*2.</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">      工作电压8V-26V，THD + 噪声>0.4 %。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">             3）、蓝牙4.2版本，传输效率高，距离远。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">       2、参数描述</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">             1）、供电电压：采用DC-005接头，供电范围：13V-24V。后分别经LDO降压后位前级放大电              路，蓝牙模块，功能选择电路供电。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/vIvyewkaFfMb8OWyOxqla0OpZPKjJnwdpFHinBXq.png" alt="电源电路" width="704" height="193"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">             2）、前级放大电路：前级放大电路借用@winton 的《【课程设计】TPA3116+M18蓝牙数字功放》中电路。采用NE5532单电源供电。NE5532在常规音频电路中多采用双电源供电。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">      音频输入端采用如图输入接口，这种接口自带音频切换功能，插入AUX时自动切断蓝牙对前级的输入。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img style="margin-left:auto;margin-right:auto;" src="//image.lceda.cn/pullimage/AjdvTzDflAkr8w4KtjIONFOcRCekJs9I2oSemob0.png" alt="前级" width="445" height="343"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img style="margin-left:auto;margin-right:auto;" src="//image.lceda.cn/pullimage/cD75OMAQCWcp0XPDjIMvP0V78jPe7jQH1TPD2tK1.png" alt="AUX端子" width="218" height="223"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">         3）、M18蓝牙模块是淘宝买的现有模块，4按键调节</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">         3、TDA7492电路介绍</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">             芯片具有静音和待机两种工作模式，本次设计只是用静音模式，静音控制引脚pin 21，低电平静音模式，蓝牙模块默认静音高电平有效，所以要加一路三极管进行电平转换。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img style="margin-left:auto;margin-right:auto;" src="//image.lceda.cn/pullimage/V2pyZCKXPxsWRO4v8kQdTZncvxgc2o19ULFKN4Ib.png" alt="" width="873" height="402"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">          芯片可以外部设置进行增益设置，本次设计中采用固定增益，增益控制印加PIN 30  PIN 31.分别接芯片内部LDO。增益控制在33.6dB.</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img style="margin-left:auto;margin-right:auto;" src="//image.lceda.cn/pullimage/UTFaPH4jW2ArPxI6QoZJ1iHejxNutDvRhIn3WkHK.png" alt="" width="855" height="192"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">      输出低通网络参考芯片手册，在4Ω负载情况下，电感选择15uH,电容470nF,电感尽量选择电流容量大些，避免低音时电感饱和。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img style="margin-left:auto;margin-right:auto;" src="//image.lceda.cn/pullimage/SAOn7KRvUXhc1aCTiJQ99nGd3Jze6sbPFMCbvwDF.png" alt="" width="237" height="142"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">二、PCB 展示</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">3D(大赛logo要验证）</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/jqgrQrSklE8DX0QQPtDB1CPnSgU93hB6JoJOYRjg.png" alt="" width="273" height="218"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/YrnRzxHvYrQc7cPQJZBSsIqoHx9Aqrbl1orFAM2G.jpeg" alt="" width="628" height="704"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">三、测试</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">       没有扬声器也没有找到大功率的水泥电阻，所以只空载测试了输入输出波形。具体看视频吧。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">       测试时供电电压用的15V在低频段高大幅值输入时出现削顶失真，提高供电电压，对输入进行衰减失真自然消失。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">      高频段时出现了不明显的交越失真，跟示波器的表笔输入电容有关，加上负载后可能会消失，后面有扬声器后再测试一次。</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">四、实物照片</p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;">     </p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"><img src="//image.lceda.cn/pullimage/vWGcxF05wO9xvdBdltfdWVGeN7TjuXuLwkaQ8EE6.jpeg" alt="" width="652" height="652"></p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> <p class="paragraph text-align-type-left pap-line-1.3 pap-line-rule-auto pap-spacing-before-3pt pap-spacing-after-3pt" style="line-height:1.8;"> </p> </div>