Philips 个人娱乐解决方案:音频放大器NXP

简介：这次在线座谈会主要介绍包括数字D类放大器在内的各种音频功率放大器的性能、封装形式、应用以及参考设计。音频功率放大器广泛应用在计算机，电视以及其它消费类电子产品中扬声器的音频放大。

问：D类放大器和AB类,A类以及C类放大器有和差别?
答： Find a text book of univercisy, you will got the answer. I am sorry for that!

问：你好！我想问的问题是关于放大器对温度敏感性方面的问题。就是说可以采取什么辅助措施降低热消耗？
答： 关于放大器对温度敏感性的问题是一个比较普遍的问题。在IC设计中，工程师们都花很多功夫去解决并改善温度变化对IC参数及指标的影响。一旦IC设计完成，其特性就不会变了，大厂的IC一般不会有这种问题出现。
至于采取什么辅助措施降低热消耗？我们应用IC时要注意的就是供电电压要按需供电，不必要高的电压会增加IC的无效发热。再有就是AMP在无信号工作时最好能进行智能静音或待机，这也是一个好办法。

问：请问电视类的音频产品有什么最新的？？
答： Currently we have the TDA8928ST and TDA8925ST designed in into mainstream TV.
For new projects we are devloping the TDA8931T whichs integrates more functionality and requires less external cxomponents. This is a mono type which can deliver 15..25W out

问：Will Philips provide TSSOP package of Class D amplifier in future?
答： Depending on application and output power.
For lower power this is possible. We are thinking
about it for the TDA8932 (Flat screen).
Basic problem for 2x15W you still will need to dissipate around 3W (90% efficiency). It is doubtfull a TSSOP pa

问：TRIPHATH的CLASS-D功放由于开关频率高,对一般的低频电源的余量要求较大(做超低音功放时),变成实用性不高.贵公司的产品有否此问题?如有,如何解决?
答： we don"t have this problem for our class D. We can use normal linear power supply due to bigger supply range (up to 60V) and internal feedback.

问：如何在机顶盒中预先实现stero/dual channel？
答： That will be implemented in audio DSP in you integreted the amplifiers in STB.

问：最后一个问题是：我所接触的一些功率比较大的放大器在应用中往往需要散热片，那究竟放大器对问题的敏感性我们在设计中要如何加以考虑呢？谢谢
答： If the temperature on the surface of the IC did not succeed that specifed in specification, everything will be OK.

问：Class-D功放可以采用开关电源吗？
答： Yes! If you need, we can introduce SMPS manufacture to you.

问：Philipsde的音频放大器的特点？同比索尼、雅马哈等同类产品的优势和性价比如何？目前市场上能够被中等收入的消费者接受的MP3品种是什么型号？如何能买得到？
答： Our one chip class D amplifier has lower EMI and no external feedback needed.

For MP3 it"s not our sibject for today. Sorry.

问：What technology Philips used in class-D, because of there is so many solution in market are using difference technology to do, like sigma-delta, PWM , multi level sigma-delta.
答： Philips has a class-D stage with analog input. We have feedback. Our system is having feedback and will generate PWM which is compensated for supply modulation.
Due to this we have a fixed gain, high Power supply rejection ratio, good S/N ratio.
Ou