LM4682 Datasheet, PDF (1/21 Pages) National Semiconductor (TI) – 10 Watt Stereo CLASS D Audio Power Amplifier with Stereo Headphone Amplifier and DC Volume Control

March 2006
LM4682
10 Watt Stereo CLASS D Audio Power Amplifier with
Stereo Headphone Amplifier and DC Volume Control
General Description
The LM4682 is a fully integrated single supply, high effi-
ciency audio power amplifier solution. The LM4682 utilizes a
proprietary balanced pulse-width modulation technique that
lowers output noise and THD and improves PSRR when
compared to conventional pulse width modulators.
The LM4682 also features a stereo headphone amplifier that
delivers 60mW into a 32Ω headset with less than 0.5% THD.
The LM4682’s DC volume control has a +30dB to –48dB
range when speakers are driven and a range of +13dB to
–65dB when headphones are connected. All amplifiers are
protected by thermal shutdown. Additionally, all amplifiers
incorporate output current limiting function to protect their
outputs from short circuit.
The LM4682 features a low-power consumption shutdown
mode. And its efficiency reaches 85% for a 10W output
power with an 8Ω load. External heatsink is not required
when playing music. The IC features click and pop reduction
circuitry that minimizes audible popping during device
turn-on and turn-off. The LM4682 is available in a 48-lead
LLP package, ideal for portable and desktop computer ap-
plications.
Key Specifications
n P_O at THD+N = 10%, V_DD = 14V
10W (typ)
n THD+N at 1kHz at 6W into 8Ω (Power Amp) 0.2% (typ)
n Efficiency at 7W into 8Ω
84% (typ)
n Total quiescent power supply current
52mA (typ)
n Total shutdown power supply current
0.1mA (typ)
n THD+N 1kHz, 20mW, 32Ω (Headphone) 0.02% (typ)
n Single supply range
8.5V to 15V
Features
n Pulse-width modulator.
n DC Volume Control
n Stereo headphone amplifier.
n “Click and pop” suppression circuitry.
n Micropower shutdown mode.
n 48 lead LLP package (No heatsink required).
Applications
n Flat Panel Displays
n Televisions
n Multimedia Monitors
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2006 National Semiconductor Corporation DS201196
www.national.com