31.08.2006, 11:38 AM
Ne ne ne,
manche sind am löten
, und die anderen sind im Urlaub. 
Kleinen Auszug aus einer Mail die ich bekommen habe:
Class-D audio power amplifiers use switched output devices to produce power with high efficiency. Various techniques are available for controlling switching patterns. A technique called BD modulation permits filter-free operation (operation without an output filter) in many applications, reducing cost and complexity.
The output devices in a Class-D amplifier operate primarily in saturation, with low voltage drops and power dissipation. Class-D amplifier efficiency can be as high as 95%, so Class-D amplifiers can reduce heat generation in high-power applications and increase battery life in handheld applications. These advantages contrast sharply with the low-efficiency of Class-AB amplifiers, as much as 25% in average operation.
The broad output spectrum of a Class-D amplifier can produce EMI if it is not properly controlled. Solutions to this sort of problem are often considered black magic. However, it is reasonably easy to achieve EMC through knowledge of EMI filter component characteristics and PCB layout principles.
The discussion will include a special focus on BD modulation as well as elements of EMC testing, filter component characteristics and proper PCB layout. We will conduct several lab sessions, including one in a working EMI chamber to illustrate EMI testing.
Gruß
manche sind am löten
, und die anderen sind im Urlaub. Kleinen Auszug aus einer Mail die ich bekommen habe:
Class-D audio power amplifiers use switched output devices to produce power with high efficiency. Various techniques are available for controlling switching patterns. A technique called BD modulation permits filter-free operation (operation without an output filter) in many applications, reducing cost and complexity.
The output devices in a Class-D amplifier operate primarily in saturation, with low voltage drops and power dissipation. Class-D amplifier efficiency can be as high as 95%, so Class-D amplifiers can reduce heat generation in high-power applications and increase battery life in handheld applications. These advantages contrast sharply with the low-efficiency of Class-AB amplifiers, as much as 25% in average operation.
The broad output spectrum of a Class-D amplifier can produce EMI if it is not properly controlled. Solutions to this sort of problem are often considered black magic. However, it is reasonably easy to achieve EMC through knowledge of EMI filter component characteristics and PCB layout principles.
The discussion will include a special focus on BD modulation as well as elements of EMC testing, filter component characteristics and proper PCB layout. We will conduct several lab sessions, including one in a working EMI chamber to illustrate EMI testing.
Gruß