LM48822_14 Datasheet, PDF (1/25 Pages) Texas Instruments – Ground-Referenced, Ultra High PSRR, Ultra Low Noise, 35mW/Channel Stereo Headphone Amplifier

LM48822, LM48822TLEVAL
www.ti.com
SNAS456B – MAY 2008 – REVISED MARCH 2011
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 µSMD
package
APPLICATIONS
• Mobile Phones
• PDAs
• Notebook PCs
• Portable Electronic Devices
• MP3 Players
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 National’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 micro SMD package (2mmx2mm).
Output Power/channel at V_DD = 3.6V
R_L = 16Ω, THD+N ≤ 1%
Output Power/channel at V_DD = 3.6V
R_L = 32Ω, THD+N ≤ 1%
Quiescent Power Supply Current at 3.6V
PSRR at 217Hz
Shutdown current
Table 1. Key Specifications
VALUE UNIT
35 mW (typ)
40 mW (typ)
3.5 mA (typ)
110 dB (typ)
0.06 μA (typ)
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 © 2008–2011, Texas Instruments Incorporated