LM4924 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – 2 Cell Battery, 40mW Per Channel Output Capacitor-Less(OCL) Stereo Headphone Audio Amplifier

October 2004
LM4924
2 Cell Battery, 40mW Per Channel Output Capacitor-Less
(OCL) Stereo Headphone Audio Amplifier
General Description
The LM4924 is a Output Capacitor-Less (OCL) stereo head-
phone amplifier, which when connected to a 3.0V supply,
delivers 40mW per channel to a 16Ω load with less than 1%
THD+N.
With the LM4924 packaged in the MM and SD packages, the
customer benefits include low profile and small size. These
packages minimizes PCB area and maximizes output power.
The LM4924 features circuitry that reduces output transients
(“clicks” and “pops”) during device turn-on and turn-off, and
Mute On and Off. An externally controlled, low-power con-
sumption, active-low shutdown mode is also included in the
LM4924. Boomer audio power amplifiers are designed spe-
cifically to use few external components and provide high
quality output power in a surface mount packages.
Key Specifications
n OCL output power
n (R_L = 16Ω, V_DD = 3.0V, THD+N = 1%) 40mW (typ)
n Micropower shutdown current
0.1µA (typ)
n Supply voltage operating range
1.5V < V_DD < 3.6V
n PSRR 100Hz, V_DD = 3.0V, A_V = 2.5
66dB (typ)
Features
n 2-cell 1.5V to 3.6V battery operation
n OCL mode for stereo headphone operation
n Unity-gain stable
n “Click and pop” suppression circuitry for shutdown On
and Off transients
n Active low micropower shutdown
n Thermal shutdown protection circuitry
Applications
n Portable two-cell audio products
n Portable two-cell electronic devices
Typical Application
FIGURE 1. Block Diagram
20121057
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© 2004 National Semiconductor Corporation DS201210
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