LM4940 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – 6W Streo Audio Power Amplifier

April 2005
LM4940
6W Stereo Audio Power Amplifier
General Description
The LM4940 is a dual audio power amplifier primarily de-
signed for demanding applications in flat panel monitors and
TV’s. It is capable of delivering 6 watts per channel to a 4Ω
load with less than 10% THD+N while operating on a
14.4V_DC power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4940 does not require boot-
strap capacitors or snubber circuits. Therefore, it is ideally
suited for display applications requiring high power and mini-
mal size.
The LM4940 features a low-power consumption active-low
shutdown mode. Additionally, the LM4940 features an inter-
nal thermal shutdown protection mechanism along with short
circuit protection.
The LM4940 contains advanced pop & click circuitry that
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4940 is a unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j Quiscent Power Supply Current
j P_OUT (SE)
V_DD = 14.4V, R_L = 4Ω, 10% THD+N
j Shutdown current
40mA (max)
6W (typ)
40µA (typ)
Features
n Pop & click circuitry eliminates noise during turn-on and
turn-off transitions
n Low current, active-low shutdown mode
n Low quiescent current
n Stereo 6W output, R_L = 4Ω
n Short circuit protection
n Unity-gain stable
n External gain configuration capability
Applications
n Flat Panel Monitors
n Flat Panel TV’s
n Computer Sound Cards
Typical Application
20075672
FIGURE 1. Typical Stereo Audio Amplifier Application Circuit
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2005 National Semiconductor Corporation DS200756
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