LM48512 Datasheet, PDF (1/17 Pages) Texas Instruments – PowerWise® Boosted, Ultra Low-EMI, Mono, E2S Class D Audio Power Amplifier

LM48512 
April 9, 2012
PowerWise® Boosted, Ultra Low-EMI, Mono, E²S Class D
Audio Power Amplifier
General 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 En-
hanced 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 op-
eration from 2.3V to 5.5V. The E²S system features a patent-
ed edge rate control (ERC) architecture that further reduces
emissions by minimizing the high frequency component of the
device output, while maintaining high quality audio reproduc-
tion (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 con-
trol (AGC). The AGC detects the battery voltage and reduces
the gain of the amplifier to limit the output as the battery volt-
age decreases.
Superior click and pop suppression eliminates audible tran-
sients on power-up/down and during shutdown.
Key Specifications
■ Power Output at V_DD = 3.6V
R_L = 8Ω, THD+N ≤ 1%
■ Efficiency at 3.6V, 800mW into 8Ω
■ Quiescent Power Supply Current
at 3.6V
■ Shutdown current
1.8W (typ)
82% (typ)
14.5mA
0.04μA (typ)
Features
■ ^{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
Typical Application
30121756
FIGURE 1. Typical Audio Amplifier Application Circuit
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