LM49250

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SNAS406C – JANUARY 2008 – REVISED MAY 2013

LM49250

Enhanced Emissions Suppression Stereo Class

D Audio Sub-System with Ground Referenced Headphone Amplifier and Mono Earpiece

Check for Samples: LM49250

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FEATURES

DESCRIPTION

The LM49250 is a fully integrated audio subsystem

2

•

Output Short Circuit Protection

designed for stereo cell phone applications. The

•

Thermal Overload Protection

LM49250 combines a 2.4W/Ch stereo class D

•

Stereo Filterless Class D Operation

speaker amplifiers with a 45mW/Ch stereo ground

referenced headphone amplifier, a class AB earpiece

•

Spread Spectrum Modulation

amplifier, TI 3D enhancement, volume control, and an

•

Ground Referenced Headphone Drivers

input mixer into a single device. The filterless class D

•

amplifiers deliver 1.2W/Ch into an 8

Ω load with <1%

THD+N from a 5V supply.

•

32-Step Input Volume Control

•

Output Volume Control

The LM49250 features a new circuit technology that

utilizes a charge pump to generate a negative supply

•

Minimum External Components

voltage. This allows the headphone outputs to be

•

Click and Pop Suppression

biased about ground, thereby eliminating the output-

•

Micro-Power Shutdown

coupling capacitors.

•

Available in Space-Saving 36–Bump DSBGA

For improved noise immunity, the LM49250 features

Package

fully differential left, right and mono inputs. The three

•

Single Supply Operation

inputs can be mixed/multiplexed to any output

combination

of

the

loudspeaker,

headphone

or

•

RF Suppression

earpiece amplifiers. The left and right differential

inputs can be used as separate single-ended inputs,

APPLICATIONS

mixing multiple stereo audio sources. The mixer,

•

Mobile Phones

volume

control,

and

device

mode

select

are

•

Portable Navigation Devices

•

Portable Media Players

KEY SPECIFICATIONS

•

–

–

–

•

Headphone:

–

–

•

Earpiece:

–

–

•

Shutdown Current: 0.1

μA

•

Efficiency at 5V, 1W into 8

Ω: 87%

•

Efficiency at 3.6V, 500mW into 8

Ω: 85%

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Products conform to specifications per the terms of the Texas

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