LM48861 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – Ground-Referenced, Ultra Low Noise, Stereo Headphone Amplifier

LM48861
March 16, 2010
Ground-Referenced, Ultra Low Noise, Stereo Headphone
Amplifier
General Description
The LM48861 is a single supply, ground-referenced stereo
headphone amplifier. Part of National's PowerWise® product
family, the LM48861 consumes only 3mW of power, yet still
provides great audio performance. The ground-referenced
architecture eliminates the larger DC blocking capacitors re-
quired by traditional headphone amplifier's saving board
space and reducing cost.
The LM48861 features common-mode sensing that corrects
for any differences between the amplifier ground and the po-
tential at the headphone return terminal, minimizing noise
created by any ground mismatches.
The LM48861 delivers 22mW/channel into a 32Ω load with
<1% THD+N with a 1.8V supply. Power supply requirements
allow operation from 1.2V to 2.8V. High power supply rejec-
tion ratio (PSRR), 83dB at 217Hz, allows the device to oper-
ate in noisy environments without additional power supply
conditioning. A low power shutdown mode reduces supply
current consumption to 0.01µA.
Superior click and pop suppression eliminates audible tran-
sients on power-up/down and during shutdown. The
LM48861 is available in an ultra-small 12-bump, 0.4mm pitch,
micro SMD package (1.215mm x 1.615mm).
Key Specifications
■ Output Power/channel at
V_DD = 1.5V, THD+N = 1%
R_L = 16Ω
R_L = 32Ω
■ Output Power/channel at
V_DD = 1.8V, THD+N = 1%
R_L = 16Ω
R_L = 32Ω
■ Quiescent Power Supply Current
at 1.5V
■ PSRR at 217Hz
■ Shutdown Current
12mW (typ)
13mW (typ)
24mW (typ)
22mW (typ)
2mA (typ)
83dB (typ)
0.01μA (typ)
Features
■ ^{Ground referenced outputs – eliminates output coupling}
capacitors
■ ^{Common-mode sensing}
■ ^{Advanced click-and-pop suppression}
■ ^{Low supply current}
■ ^{Minimum external components}
■ ^{Micro-power shutdown}
■ ^{ESD protection of 8kV HBM contact}
■ ^{Available in space-saving 12-bump microSMD package}
Applications
■ ^{Mobile Phones}
■ ^{Portable electronic devices}
■ ^{MP3 Players}
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