1FEATURES
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-
Recovery
• 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

APPLICATIONS
• Mobile Phones
• PDAs
• Laptops

KEY SPECIFICATIONS
• 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) auto–
THD+N ≤ 1% 2.1W (Typ)
• Power Output at V DD = 5V, RL = 8Ω
– THD+N ≤ 10% 1.6W (Typ)
– THD+N ≤ 1% 1.3W (Typ)
• Shutdown Current 0.01μA (Typ)

DESCRIPTION
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.