LM49151 Datasheet, PDF (1/4 Pages) National Semiconductor (TI) – Mono Class D Audio Subsystem with Earpiece Driver, Ground Referenced Headphone Amplifiers, Speaker Protection and No Clip with Clip Control

LM49151
PRODUCT BRIEF
PRELIMINARY
April 16, 2009
Mono Class D Audio Subsystem with Earpiece Driver,
Ground Referenced Headphone Amplifiers, Speaker
Protection and No Clip with Clip Control
General Description
The LM49151 is a fully integrated audio subsystem designed
for portable handheld applications such as cellular phones.
The LM49151 combines a 1.25W mono E²S class D amplifier,
125mW Class AB earpiece driver, 42mW/channel stereo
ground referenced headphone drivers, volume control, input
mixer/multiplexer, and speaker protection into a single de-
vice.
The LM49151 class D speaker amplifier features National’s
unique Automatic Level Control (ALC) that provides both a
I²C programmable no-clip feature with Clip Controls and
speaker protection. The E²S (Enhanced Emission Suppres-
sion) class D amplifier features a patented, ultra low EMI
PWM architecture that significantly reduces RF emissions
while preserving audio quality and efficiency while delivering
1.25W into an 8Ω load with <1% THD+N with a 5V supply.
The 42mW/channel headphone drivers feature National’s
ground referenced architecture that creates a ground-refer-
enced output from a single supply, eliminating the need for
bulky and expensive DC-blocking capacitors, saving space
and minimizing system cost.
The LM49151 features separate volume controls for the loud-
speaker and headphone inputs. Mode selection, shutdown
control, and volume are controlled through an I²C compatible
interface. The LM49151's superior click and pop suppression
eliminates audible transients on power-up/down and during
shutdown.
Notice: This document is not a full datasheet. For more
information regarding this product or to order samples
please contact your local National Semiconductor sales
office or visit http://www.national.com/support/dir.html
Key Specifications
■ Output power at V_DD = 3.3V
  THD+N ≤ 1%
LS Mode, R_L = 8Ω
HP Mode, R_L = 32Ω
■ Output power at V_DD = 5V
  THD+N ≤ 1%
LS Mode, R_L = 8Ω
HP Mode, R_L = 32Ω
■ Output Offset
  LS Mode 15
  HP Mode 15
520mW (typ)
40mW (typ)
1.25W (typ)
42mW (typ)
6mV (typ)
2mV (typ)
Features
■ ^{E2S class D amplifier}
■ ^{Ground referenced outputs — eliminates output coupling}
capacitors
■ ^{I2C programmable No Clip Function with Clip Control}
■ ^{Voltage limiter speaker protection}
■ ^{I2C volume and mode Control}
■ ^{Ear Piece Amplifier}
■ ^{Advanced click-and-pop suppression}
■ ^{Low supply current}
■ ^{Micro-power shutdown}
■ ^{20-bump micro SMD package}
Applications
■ ^{Mobile Phones}
■ ^PDAs
■ ^{Notebook PCs}
■ ^{Portable Electronics Devices}
■ ^{MP3 Players}
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