LM4921

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SNAS178E – JULY 2003 – REVISED MAY 2013

LM4921

Low Voltage I2S 16-Bit Stereo DAC with Stereo

Headphone Power Amplifiers and Volume Control

Check for Samples: LM4921

1

FEATURES

APPLICATIONS

2

•

16-Bit Resolution Stereo DAC

•

Mobile Phones

•

I2S Digital Audio Data Serial Interface

•

PDAs

•

SPI Serial Interface (Control Register)

•

Portable Electronic Devices

•

Volume Control (32 steps; 1.5 dB Increments)

DESCRIPTION

•

Up to 50mW/Channel Stereo Headphone

The LM4921 combines a 16-bit resolution stereo I2S

Amplifier

input digital-to-analog converter (DAC) with a stereo

•

Zero Crossing Detection for Silent Attenuation

headphone audio power amplifier. It is primarily

Steps

designed

for

demanding

applications

in

mobile

phones and other portable communication device

•

2.6VDC to 5.0VDC Digital Supply Voltage Range

applications. The LM4921 features an I2S serial

•

2.6VDC to 5.5VDC Analog Supply Voltage Range

interface for the digital audio information and a 16-bit

(See (1))

SPI serial interface for internal register control and

•

Unity-Gain Stable Headphone Amplifiers

communication. With AVDD and DVDD = 3.0VDC and

driving a 32

Ω single-ended load to a 26mWRMS

•

Available in the 20-bump DSBGA Package

output level the distortion (THD+N) of the LM4921 will

be less than 0.5%. The LM4921 also features a

KEY SPECIFICATIONS

programmable

32-step

digital

volume

control

•

PSRR at 217Hz, A/DVDD = 3V, (See Figure 1):

accessed through an SPI interface.

52dB (typ)

Boomer

audio

power

amplifiers

were

designed

•

POUT at AVDD = 3.0V, 32Ω

specifically to provide high quality output power with a

–

< 0.05% THD: 13mW (typ)

minimal amount of external components. It is,

therefore, ideally suited for mobile phone and other

–

< 0.05% THD: 26mW (typ)

low

voltage

applications

where

minimal

power

•

Supply Voltage Range

consumption is a primary requirement.

–

DVDD: 2,6V to 5.0V

The LM4921 features a low-power consumption

–

AVDD: (See

(1)) 2.6V to 5.5V

shutdown mode, and also has an internal thermal

•

Shutdown Current: 1µA (typ)

shutdown protection mechanism.

(1)

Best operation is achieved by maintaining 3.0V

≤ AVDD ≤ 5.0V

and 3.0V

≤ DVDD ≤ 5.0V.

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

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

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2003–2013, 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.