LM4938 Datasheet, PDF (1/34 Pages) National Semiconductor (TI) – Stereo 2W Audio Power Amplifiers with DC Volume Control and Selectable Gain

LM4938
www.ti.com
SNAS245B – FEBRUARY 2005 – REVISED MAY 2013
LM4938 Boomer™ Audio Power Amplifier Series Stereo 2W Audio Power Amplifiers
with DC Volume Control and Selectable Gain
Check for Samples: LM4938
FEATURES
1
•23 Improved Click and Pop Circuitry Virtually
Eliminates Noise During Turn On/Off
Transitions
• DC Volume Control Interface
• System Beep Detect
• Stereo Switchable Bridged/Single-Ended
Power Amplifiers
• Selectable Internal/External Gain and Bass
Boost
• Thermal Shutdown Protection Circuitry
• Unity Gain Stable
APPLICATIONS
• Flat Panel Displays
• Portable and Desktop Computers
• Multimedia Monitors
• Portable Radios, PDAs, and Portable TVs
KEY SPECIFICATIONS
• P_O at 1% THD+N
– into 3Ω: 2.2W (typ)
– into 4Ω: 2.0W (typ)
– into 8Ω: 1.3W (typ)
• Single-ended mode
– THD+N at 92mW into 32Ω: 1.0% (typ)
• Shutdown Current: 0.5µA (typ)
DESCRIPTION
The LM4938 is a monolithic integrated circuit that
provides DC volume control, and stereo bridged
audio power amplifiers capable of producing 2W into
4Ω with less than 1.0% THD or 2.2W into 3Ω with
less than 1.0% THD.
Boomer audio integrated circuits were designed
specifically to provide high quality audio while
requiring a minimum amount of external components.
The LM4938 incorporates a DC volume control,
stereo bridged audio power amplifiers and a
selectable gain or bass boost, making it optimally
suited for multimedia monitors, portable radios,
desktop, and portable computer applications.
The LM4938 features an externally controlled, low-
power consumption shutdown mode, and both a
power amplifier and headphone mute for maximum
system flexibility and performance.
Note 1: When properly mounted to the circuit board,
LM4938MH will deliver 2W into 4Ω. See Application
Information section HTSSOP PACKAGE PCB
MOUNTING CONSIDERATIONS for more
information.
Note 2: An LM4938MH that has been properly
mounted to the circuit board and forced-air cooled will
deliver 2.2W into 3Ω.
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.
Boomer is a trademark of Texas Instruments.
2
All other trademarks are the property of their respective owners.
3
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2013, Texas Instruments Incorporated