LM48822 Datasheet, PDF (1/22 Pages) National Semiconductor (TI) – Ground-Referenced, Ultra High PSRR, Ultra Low Noise, 35mW/Channel Stereo Headphone Amplifier with CommonMode Sense, and I2C Volume Control

LM48822, LM48822TLEVAL
www.ti.com
SNAS456C – MAY 2008 – REVISED MAY 2013
LM48822 Boomer ™ Ground-Referenced, Ultra High PSRR, Ultra Low Noise,
35mW/Channel Stereo Headphone Amplifier with Common Mode Sense, and I²C Volume
Control
Check for Samples: LM48822, LM48822TLEVAL
FEATURES
1
•23 Ground Referenced Outputs – Eliminates
Output Coupling Capacitors
• Common-Mode Sense
• Ultra-High PSRR
• I²C Volume and Mode Control
• High Output Impedance in Shutdown
• Differential Inputs
• Advanced Click-and-Pop Suppression
• Low Supply Current
• Minimum External Components
• Micro-Power Shutdown
• Available in Space-Saving 16-Bump DSBGA
Package
APPLICATIONS
• Mobile Phones
• PDAs
• Notebook PCs
• Portable Electronic Devices
• MP3 Players
KEY SPECIFICATIONS
• Output Power/Channel at V_DD = 3.6V
– R_L = 16Ω, THD+N ≤ 1%: 35mW (typ)
• Output Power/Channel at V_DD = 3.6V
– R_L = 32Ω, THD+N ≤ 1%: 40mW (typ)
• Quiescent Power Supply Current at 3.6V:
3.5mA (typ)
• PSRR at 217Hz: 110dB (typ)
• Shutdown Current: 0.06μA (typ)
DESCRIPTION
The LM48822 is a single supply, ground-referenced
stereo headphone amplifier designed for portable
devices, such as cell phones, where board space is
at a premium. The LM48822 features TI’s ground-
referenced architecture, which eliminates the large
DC blocking capacitor required by traditional
headphone amplifiers, saving board space and
minimizing system cost.
The LM48822 features 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.
The LM48822 delivers 35mW/channel into a 16Ω
load with <1% THD+N with a 3.6V supply. High
power supply rejection ratio (PSRR), of 110dB at
217Hz, allows the device to operate in noisy
environments without additional power supply
conditioning. Flexible power supply requirements
allow operation from 2.4V to 5.5V. The LM48822 has
a differential inputs for improved noise rejection. High
output impedance in Shutdown mode, combined with
a charge pump-only mode allows the LM48822's
outputs to be driven by an external source without
degrading the source signal. Additionally, the
LM48822 features a 64-step I²C volume control and
mute function. The low power Shutdown mode
reduces supply current consumption to 0.06µA.
Superior click and pop suppression eliminates audible
transients on power-up/down and during shutdown.
The LM48822 is available in an ultra-small 16-bump
DSBGA package (2mmx2mm).
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.
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 © 2008–2013, Texas Instruments Incorporated