Ceramic Speaker Driver
National Semiconductor Corp. introduces a single-chip Boomer audio power amplifier for driving ceramic speakers used in a wide range of 3V portable devices. The LM48555 drives ceramic speakers in small handheld devices such as cell phones, smartphones, notebook computers. With a ceramic speaker load equivalent to 1 µF + 20 Ohm, it provides a voltage drive of 15.7V peak-to-peak with less than 1 percent total harmonic distortion plus noise (THD+N). In addition, its 12-bump micro SMD package has a footprint of 1.5 mm × 2.0 mm, making it possible for manufacturers to create ultra-thin, feature-rich handsets. The amplifier’s pop-and-click circuitry eliminates noise that typically occurs during turn-ON and turn-OFF transitions.