LM48557 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – Mono, Bridge-Tied Load, Ceramic Speaker Driver with I2C Volume Control and Reset

LM48557
August 6, 2009
Mono, Bridge-Tied Load, Ceramic Speaker Driver with I²C
Volume Control and Reset
General Description
The LM48557 is a single supply, mono, ceramic speaker driv-
er with an integrated charge-pump, designed for portable
devices, such as cell phones and portable media players,
where board space is at a premium. The LM48557 charge
pump allows the device to deliver 5.8V_RMS from a single 4.2V
supply.
The LM48557 features high power supply rejection ratio
(PSRR), 80dB at 217Hz, allowing the device to operate in
noisy environments without additional power supply condi-
tioning. Flexible power supply requirements allow operation
from 2.7V to 4.5V. The LM48557 features an active low reset
input that reverts the device to its default state. Additionally,
the LM48557 features a 36-step I²C volume control and mute
function. The low power Shutdown mode reduces supply cur-
rent consumption to 0.01µA.
The LM48557’s superior click and pop suppression elimi-
nates audible transients on power-up/down and during shut-
down. The LM48557 is available in an ultra-small 16-bump
micro SMD package (1.965mmx1.965mm).
Key Specifications
■ Output Voltage at V_DD = 4.2V
R_L = 1µF +22Ω, THD+N ≤ 1%
■ Quiescent Power Supply Current
at 4.2V
■ PSRR at 217Hz
■ Shutdown current
5.8V_RMS (typ)
5mA (typ)
80dB (typ)
0.01μA (typ)
Features
■ ^{Integrated Charge Pump}
■ ^{Bridge-tied Load Output}
■ ^{Differential Input}
■ ^{High PSRR}
■ ^{I2C Volume and Mode Control}
■ ^{Reset Input}
■ ^{Advanced Click-and-Pop Suppression}
■ ^{Low Supply Current}
■ ^{Minimum external components}
■ ^{Micro-power shutdown}
■ ^{Available in space-saving 16-bump micro SMD package}
Applications
■ ^{Mobile phones}
■ ^PDAs
■ ^{Notebook Electronic Devices}
■ ^{MP3 Players}
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