LM4901 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – 1.6 Watt Audio Power Amplifier with Selectable Shutdown Logic Level

December 2002
LM4901
1.6 Watt Audio Power Amplifier with Selectable
Shutdown Logic Level
General Description
The LM4901 is an audio power amplifier primarily designed
for demanding applications in mobile phones and other por-
table communication device applications. It is capable of
delivering 1 watt of continuous average power to an 8Ω BTL
load and 1.6 watts of continuous avearge power to a 4Ω BTL
load with less than 1% distortion (THD+N) from a 5V_DC
power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4901 does not require output
coupling capacitors or bootstrap capacitors, and therefore is
ideally suited for mobile phone and other low voltage appli-
cations where minimal power consumption is a primary re-
quirement.
The LM4901 features a low-power consumption shutdown
mode. To facilitate this, Shutdown may be enabled by either
logic high or low depending on mode selection. Driving the
shutdown mode pin either high or low enables the shutdown
pin to be driven in a likewise manner to enable shutdown.
The LM4901 contains advanced pop & click circuitry which
eliminates noise which would otherwise occur during turn-on
and turn-off transitions.
The LM4901 is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
j Improved PSRR at 217Hz & 1KHz
j Power Output at 5.0V, 1% THD, 4Ω
j Power Output at 5.0V, 1% THD, 8Ω
j Power Output at 3.0V, 1% THD, 4Ω
j Power Output at 3.0V, 1% THD, 8Ω
j Shutdown Current
62dB
1.6W (typ)
1.07W (typ)
525mW (typ)
390mW (typ)
0.1µA (typ)
Features
n Available in space-saving packages: LLP, micro SMD,
and MSOP
n Ultra low current shutdown mode
n BTL output can drive capacitive loads
n Improved pop & click circuitry eliminates noise during
turn-on and turn-off transitions
n 2.0 - 5.5V operation
n No output coupling capacitors, snubber networks or
bootstrap capacitors required
n Unity-gain stable
n External gain configuration capability
n User selectable shutdown High or Low logic Level
Applications
n Mobile Phones
n PDAs
n Portable electronic devices
Typical Application
20019801
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2002 National Semiconductor Corporation DS200198
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