LM4947, LM4947TLEVAL

www.ti.com

SNAS349D – JUNE 2006 – REVISED MAY 2013

LM4947

Mono Class D and Stereo Audio Sub-System

with OCL Headphone Amplifier and TI 3D

Check for Samples: LM4947, LM4947TLEVAL

1

FEATURES

DESCRIPTION

The LM4947 is an audio subsystem capable of

2

•

efficiently delivering 500mW (Class D operation) of

•

continuous average power into a mono 8

Ω bridged-

Audio

tied load (BTL) with 1% THD+N, 37mW (Class AB

•

operation) power channel of continuous average

power into stereo 32

Ω single-ended (SE) loads with

(-59.5dB to +18dB)

1% THD+N, or an output capacitor-less (OCL)

•

Three Independent Volume Channels (Left,

configuration with identical specification as the SE

Right, Mono)

configuration, from a 3.3V power supply.

•

Eight Distinct Output Modes

The LM4947 has six input channels: one pair for a

•

Small, 25–Bump DSBGA Packaging

two-channel stereo signal, the second pair for a

•

“Click and Pop” Suppression Circuitry

secondary two-channel stereo input, and the third pair

for

a

differential

single-channel

mono

input.

•

Thermal Shutdown Protection

Additionally, the two sets of stereo inputs may be

•

Low Shutdown Current (0.1

μA, typ)

configured as a single stereo differential input

•

RF Suppression

(differential left and differential right). The LM4947

features a 32-step digital volume control and eight

•

Differential Mono and Stereo Inputs

distinct output modes. The digital volume control, 3D

•

Stereo Input Mux

enhancement, and output modes are programmed

KEY SPECIFICATIONS

allows flexibility in routing and mixing audio channels.

•

THD+N at 1kHz, 500mW

into 8

Ω BTL (3.3V):

The RF suppression circuitry in the LM4947 makes it

1.0% (typ)

well-suited

for

GSM

mobile

phones

and

other

•

THD+N at 1kHz, 37mW

into 32

Ω SE (3.3V):

portable applications in which strong RF signals

1.0% (typ)

generated by an antenna (and long output traces)

may couple audibly into the amplifier.

•

The LM4947 is designed for cellular phones, PDAs,

•

and other portable handheld applications. It delivers

high quality output power from a surface-mount

APPLICATIONS

package and requires only eight external components

•

Mobile Phones

in the OCL mode (two additional components in SE

mode).

•

PDAs

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2006–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.