LM4980 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – 2 Cell Battery, 1mA, 42mW Per Channel High Fidelity Stereo Headphone Audio Amplifier for MP3 players

July 2005
LM4980
2 Cell Battery, 1mA, 42mW Per Channel High Fidelity
Stereo Headphone Audio Amplifier for MP3 players
General Description
The LM4980 is a stereo headphone audio amplifier, which
when connected to a 3.0V supply, delivers 42mW to a 16Ω
load with less than 1% THD+N. With the LM4980 packaged
in the SD package, the customer benefits include low profile
and small size. This package minimizes PCB area and maxi-
mizes output power.
The LM4980 features circuitry that significantly reduces out-
put transients (“clicks” and “pops”) while driving headphones
during device turn-on and turn-off without costly external
additional circuitry. The LM4980 also includes an externally
controlled low-power consumption active-low shutdown
mode, and thermal shutdown. Boomer audio power amplifi-
ers are designed specifically to use few external compo-
nents and provide high quality output power in a surface
mount package.
Key Specifications
j Output power
(RL = 16Ω, V_DD = 3.0V, THD+N = 1%) 42mW (typ)
j Quiescent current (V_DD = 3V)
1mA (typ)
j Micropower shutdown current
0.1µA (typ)
j Supply voltage operating range 1.5V < V_DD < 3.3V
j PSRR @ 1kHz, V_DD = 3.0V
90dB (typ)
j PSRR @ 217Hz, V_DD = 3.0V
100dB (typ)
Features
n 2-cell 1.5V to 3.3V battery operation
n Unity-gain stable
n “Click and pop” suppression circuitry for shutdown and
power on/off transient with headphone loads
n Active low micro-power shutdown
n Thermal shutdown protection circuitry
Applications
n Portable two-cell audio products
n Portable two-cell electronic devices
n Portable MP3 player/recorders
Typical Application
FIGURE 1. Block Diagram
20142901
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© 2005 National Semiconductor Corporation DS201429
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