SNAS484B – JUNE 2009 – REVISED MAY 2013
LM48311 Boomer™ Audio Power Amplifier Series Ultra-Low EMI, Filterless, 2.6W, Mono,
Class D Audio Power Amplifier with E2S
Check for Samples: LM48311
•23 Passes FCC Class B Radiated Emissions with
20 Inches of Cable
• E2S System Reduces EMI while Preserving
Audio Quality and Efficiency
• Output Short Circuit Protection with Auto-
• No output Filter Required
• Internally Configured Gain (6dB)
• Low power Shutdown Mode
• Minimum External Components
• "Click and Pop" Suppression
• Micro-Power Shutdown
• Available in Space-Saving DSBGA Package
• Mobile Phones
• Efficiency at 3.6V, 400mW into 8Ω 85% (Typ)
• Efficiency at 5V, 1W into 8Ω 88% (Typ)
• Quiescent Power Supply Current at 5V 3.1mA
• Power Output at VDD = 5V, RL = 4Ω
– THD+N ≤ 10% 2.6W (Typ)
– THD+N ≤ 1% 2.1W (Typ)
• Power Output at VDD = 5V, RL = 8Ω
– THD+N ≤ 10% 1.6W (Typ)
– THD+N ≤ 1% 1.3W (Typ)
• Shutdown Current 0.01μA (Typ)
The LM48311 is a single supply, high efficiency,
mono, 2.6W, filterless switching audio amplifier. The
LM48311 features Texas Instruments' Enhanced
Emissions Suppression (E2S) system, that features a
unique patent-pending ultra low EMI, spread
spectrum, PWM architecture, that significantly
reduces RF emissions while preserving audio quality
and efficiency. The E2S system improves battery life,
reduces external component count, board area
consumption, system cost, and simplifying design.
The LM48311 is designed to meet the demands of
portable multimedia devices. Operating from a single
5V supply, the device is capable of delivering 2.6W of
continuous output power to a 4Ω load with less than
10% THD+N. Flexible power supply requirements
allow operation from 2.4V to 5.5V. The LM48311
features both a spread spectrum modulation scheme,
and an advanced, patented edge rate control (ERC)
architecture that significantly reduces emissions,
while maintaining high quality audio reproduction
(THD+N = 0.03%) and high efficiency (η = 88%).
The LM48311 features high efficiency compared to
conventional Class AB amplifiers, and other low EMI
Class D amplifiers. When driving and 8Ω speaker
from a 5V supply, the device operates with 88%
efficiency at PO = 1W. The gain of the LM48311 is
internally set to 6dB, further reducing external
component count. A low power shutdown mode
reduces supply current consumption to 0.01µA.
Advanced output short circuit protection with auto-
recovery prevents the device from being damaged
during fault conditions. Superior click and pop
suppression eliminates audible transients on power-
up/down and during shutdown.
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.
All other trademarks are the property of their respective owners.
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 © 2009–2013, Texas Instruments Incorporated