PAPER SESSION 4: CONTROL/PROTECTION SYSTEM
A Speaker Protection Scheme for Class D PWM
Alexandre Huffenus(1), Gael Pillonnet(2),
Robert Cittadini(3), Vincent Rabary(3).
(1) EASII IC, Grenoble, France.
(2) Institut des Nanotechnologies de Lyon, Villeurbanne,
(3) ST Microelectronics, Grenoble, France.
Switched mode (class D) audio amplifiers gained
much popularity in low power applications during the
last decade thanks to their high efficiency, compactness,
and increasing sound quality. They have
become the technology of choice for battery operated
systems such as mobile phones, PDAs, portable
media players, etc. In such applications it is critical to
protect the microspeakers from an excessive output
power that could result from severe amplifier clipping. A
current and area effective solution is presented in this
paper, to limit the clipping from the Class D amplifier.