LM48824 Datasheet, PDF (1/29 Pages) National Semiconductor (TI) – Class G Headphone Amplifier with I2C Volume Control

LM48824
www.ti.com
SNAS479D – MARCH 2009 – REVISED MAY 2013
LM48824
Class G Headphone Amplifier
with I²C Volume Control
Check for Samples: LM48824
FEATURES
1
•2 Class G Power Savings
• Ground Referenced Headphone Outputs –
Eliminates Output Coupling Capacitors
• Common-Mode Sense
• I²C Volume and Mode Control
• High Output Impedance in Shutdown
• Differential Inputs
• Advanced Click-and-Pop Suppression
• Low Supply Current
• Low THD Mode Option
APPLICATIONS
• Mobile Phones, PDAs, MP3 Players
• Portable Electronic Devices, Notebook PCs
KEY SPECIFICATIONS
• Quiescent Power Supply Current at 3.6V:
0.9mA (typ)
• Output Power/Channel at V_DD = 3.6V (R_L = 16Ω,
THD+N ≤ 1%): 37 mW (Typ)
• Output Power/Channel at V_DD = 3.6V (R_L = 32Ω,
THD+N ≤ 1%): 29 mW (Typ)
• PSRR at 217Hz: 100 dB (Typ)
• Shutdown Current: 2.5 μA (Typ)
DESCRIPTION
The LM48824 is a Class G, ground-referenced stereo
headphone amplifier designed for portable devices.
The LM48824 features TI’s ground-referenced
architecture, which eliminates the large DC blocking
capacitors required by traditional headphone
amplifiers, saving board space and minimizing
system cost.
The LM48824 takes advantage of TI’s patent-pending
Class G architecture offering power savings
compared to a traditional Class AB headphone
amplifier. Additionally, output noise is improved by
common-mode sensing that corrects for any
differences between the amplifier ground and the
potential at the headphone return terminal, minimizing
noise created by any ground mismatches.
A high output impedance mode allows the LM48824's
outputs to be driven by an external source without
degrading the signal. Other features include flexible
power supply requirements, differential inputs for
improved noise rejection, a low power (2.5μA)
shutdown mode, and a 32-step I²C volume control
with mute function.
The LM48824's superior click and pop suppression
eliminates audible transients on power-up/down and
during shutdown. The LM48824 is available in an
ultra-small 16-bump, 0.4mm pitch DSBGA package
(1.69mm x 1.69mm)
Simplified Block Diagram
Left
Right
VOLUME
CONTROL
GND
V+
SCL
Digital
POWER
SDA
Interface
SUPPLY
V-
LM48824
1
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2
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.
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