1FEATURES

2? E2S System Reduces EMI while Preserving Audio Quality and Efficiency

? Integrated Boost Converter

? Supply Voltage Level Detection on Boost

Converter

? Low Power Shutdown Mode

? Click and Pop suppression

APPLICATIONS

? Mobile phones

? Smart phones

? PDAs

DESCRIPTION

Part of National’s PowerWise family or products, the LM48512 delivers 1.8W into 8Ω, while consuming 14.5mA

of quiescent current. The LM48512 also features National’s Enhanced Emissions Suppression (E2S) system, a

patented, ultra low EMI PWM architecture that significantly reduces RF emissions while preserving audio quality

and efficiency. LM48512 improves battery life, reduces external component count, board area consumption,

system cost, and simplifies design.

The LM48512 is designed to meet the demands of portable multimedia devices. The LM48512 features high

efficiency compared to other boosted amplifiers and low EMI Class D amplifiers. The LM48512 is capable of

driving an 8Ω speaker to 5.5V levels (1.8W) from a 3.6V supply while operating at 82% efficiency. Flexible power

supply requirements allow operation from 2.3V to 5.5V. The E2S system features a patented edge rate control

(ERC) architecture that further reduces emissions by minimizing the high frequency component of the device

output, while maintaining high quality audio reproduction (THD+N = 0.03%) and high efficiency. A low power

shutdown mode reduces supply current consumption to 0.04μA.

The LM48512 features a battery-saving automatic gain control (AGC). The AGC detects the battery voltage and

reduces the gain of the amplifier to limit the output as the battery voltage decreases.

Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown.