Class D Amplifier, Microsemi


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Microsemi offers Class D Audio solutions for low power (< 1Watt) and high power (> 15 Watts) applications.

Designed for applications requiring the highest levels of efficiency and effective heat dissipation, Microsemi's

Audio IC line is ideally suited for Notebook Computers, Desktop Multimedia Systems, Wireless Speaker

Systems, Hearing Aids and other power conscious applications.


Features and Benefits of Class D:

  • Replaces existing internal low power linear amplifier with a high efficiency Class D amplifier.
  • Enables the use of virtually any external speaker without amplification.
  • Precious battery life is extended.
  • Fully protected power topology can withstand shorts or external speaker failures without damage, overheating or posing fire hazard.
  • Greatly reduced power supply requirements when compared to a linear solution of same power capabilities.
  • Any speakers can be used including conventional home stereo speakers.
  • Multimedia amplifier can be directly incorporated on the motherboard using surface mount components.


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    Amplifier Classes Amplifier Type Output Transistors Advantages Disadvantages Comments
    Class A Linear Always conducting for entire cycle: bias current > max output current Sound the best, most linear, lowest distortion Waste power, most inefficient (~20% efficiency), large/heavy, run hot Only 10% of the "high end" market
    Class B Linear Opposite operation of Class A. Both devices are never "on" at same time. Zero idle bias current. Each output device is "on" for one half cycle Better efficiency than Class A Poor linearity around crossover region, audible crossover distortion with small signals Not used in audio. Two way radio
    Class C Linear Output device is "on" for < one half cycle (pulsed-on) Class B efficiency. Capable of large output power Distortion Not used in audio. Broadcast industry for RF transmission
    Class AB Linear Combines Class A & B. Mid-conduction, constant bias current (barely on) Class A sound quality with good efficiency. Dominate the market Power dissipation as heat. ~50% efficien Most popular audio amp design
    Class D Switching Switch is fully "on" or "off", P = I x V = 0 Best efficiency 80% to 90% Old design were limited to <10kHz. Not as good THD Use pulse modulation



    Class D Evaluation Kits are available from stock Dättwil. Price per unit is CHF 100.00


    Class-D Audio Selector guide...

    more about Audio Max Products...


     

    Microsemi TEC Controllers

    Microsemi offers a family of highly efficient Class-D controllers providing thermal management solutions ideal for many of these TEC applications. Their pulse width modulated (PWM) architecture provides current to the TEC more efficiently, thereby minimizing excess power and heat dissipation.

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    Application TEC...


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