LM4910
www.ti.com
SNAS151G – MAY 2004 – REVISED MARCH 2007
LM4910
Output Capacitor-less Stereo 35mW Headphone
Amplifier
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LM4910
1
FEATURES
•
Available in space-saving MSOP, LLP, and
SOIC packages
2
•
Eliminates headphone amplifier output
coupling capacitors
APPLICATIONS
•
Eliminates half-supply bypass capacitor
•
Mobile Phones
•
Advanced pop & click circuitry eliminates
•
PDAs
noises during turn-on and turn-off
•
Portable electronics devices
•
Ultra-low current shutdown mode
•
Portable MP3 players
•
Unity-gain stable
•
2.2V - 5.5V operation
DESCRIPTION
The LM4910 is an audio power amplifier primarily designed for headphone applications in portable device
applications. It is capable of delivering 35mW of continuous average power to a 32
Ω
load with less than 1%
distortion (THD+N) from a 3.3V
DC
power supply.
The LM4910 utilizes a new circuit topology that eliminates output coupling capacitors and half-supply bypass
capacitors. The LM4910 contains advanced pop & click circuitry which eliminates noises caused by transients
that would otherwise occur during turn-on and turn-off.
Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal
amount of external components. Since the LM4910 does not require any output coupling capacitors, half-supply
bypass capacitors, or bootstrap capacitors, it is ideally suited for low-power portable applications where minimal
space and power consumption are primary requirements.
The LM4910 features a low-power consumption shutdown mode, activated by driving the shutdown pin with logic
low. Additionally, the LM4910 features an internal thermal shutdown protection mechanism. The LM4910 is also
unity-gain stable and can be configured by external gain-setting resistors.
Table 1. Key Specifications
VALUE
UNIT
PSRR at f = 217Hz
65
dB (typ)
Power Output at V
DD
= 3.3V, R
L
= 32
Ω
, and THD
≤
1%
35
mW (typ)
Shutdown Current
0.1
µA (typ)
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 © 2004–2007, 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.
