jpgey, j'ai lu les liens que tu nous as donnés.
http://www.ti.com/lit/an/snaa034a/snaa034a.pdfFigure 1 compares the efficiency of the LM4673, a mono 2.65W Class D amplifier to a similar Class AB amplifier.
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Filterless amplifiers, along with improvements in performance, enable manufacturers of such products as cell phones, PDAs, and laptops to produce feature rich, portable multimedia devices with a smaller form factor and longer battery life.
https://www.eetimes.com/filterless-clas ... er-design/Class D amplifiers have lower supply current: Class D amplifiers can drive the same output power as a Class AB amplifier using less supply current. This is a major benefit for systems with a limited power supply. For example, the USB port supplies a 5-V, 500-mA power supply. This supply can be used to power a 2-W Class D amplifier, but a Class AB amplifier requires more supply current to drive 2 W.
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Class D amplifiers offer longer battery life to portable devices
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ELIMINATING THE OUTPUT FILTER
This section will focus on why the user can eliminate the output filter with the filterless modulation scheme. The advantages and disadvantages of not using a filter will also be discussed. Any measurements of the filterless modulation scheme were made with the TPA2000D2.
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Choosing a Class D output filter: Cost is a primary concern with most products today. Therefore, if you don't need a filter, why use one? An LC filter costs approximately $1 for a 2-W stereo Class D amplifier. With the filterless modulation scheme the filter can be eliminated as long as EMI is not a problem. The TPA2000D2 EVM passed FCC and CE radiated-emissions tests for speaker wires less than eight inches (20 cm). So, if you can get by with speaker wires shorter than eight inches, don't use an output filter.
Pour ton info, voici les spécs du TPA2000D2 :
https://www.ti.com/lit/ds/symlink/tpa2000d2.pdf C'est un ampli qui sort du 2 W sous 3 ohms !
On ne peut pas comprendre le sens de ces papiers si on ne connaît pas les enjeux commerciaux qui sont derrière. Depuis une vingtaine d'années, il y a des tonnes de puces classe AB de 1 ou 2 W pour les téléphones mobiles et autres petits appareils avec HP intégrés. Ces puces ne valent pas grand chose (quelques dollars). Alors, sortir des puces classe D qui permettent d'économiser sur la batterie et de se passer d'un circuit LC, ça permet à TI de vendre ses nouvelles puces un peu plus cher et de restaurer ses marges.