LM4951A Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – Wide Voltage Range 1.8 Watt Audio Amplifier With Short Circuit Protection

September 5, 2008
LM4951A
Wide Voltage Range 1.8 Watt Audio Amplifier With Short
Circuit Protection
General Description
The LM4951A is an audio power amplifier designed for ap-
plications with supply voltages ranging from 2.7V up to 9V.
The LM4951A is capable of delivering 1.8W continuous av-
erage power with less than 1% THD+N into a bridge connect-
ed 8Ω load when operating from a 7.5VDC power supply.
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4951A does not require boot-
strap capacitors, or snubber circuits.
The LM4951A features a low-power consumption active-low
shutdown mode. Additionally, the LM4951A features an in-
ternal thermal shutdown protection mechanism and short
circuit protection.
The LM4951A contains advanced pop & click circuitry that
eliminates noises which would otherwise occur during turn-on
and turn-off transitions.
The LM4951A is unity-gain stable and can be configured by
external gain-setting resistors.
Key Specifications
Features
■ ^{Pop & click circuitry eliminates noise during turn-on and}
turn-off transitions
■ ^{Wide supply voltage range: 2.7V to 9V}
■ ^{Low current, active-low shutdown mode}
■ ^{Low quiescent current}
■ ^{Thermal shutdown protection}
■ ^{Short circuit protection}
■ ^{Unity-gain stable}
■ ^{External gain configuration capability}
Applications
■ ^{Portable devices}
■ ^{Cell phones}
■ ^{Laptop computers}
■ ^{Computer speaker systems}
■ ^{MP3 player speakers}
■ Wide Voltage Range
■ Quiescent Power Supply Current
(V_DD = 7.5V)
■ Power Output BTL at 7.5V,
1% THD
■ Shutdown Current
■ Fast Turn on Time
2.7V to 9V
2.5mA (typ)
1.8W (typ)
0.01µA (typ)
25ms (typ)
Boomer^® is a registered trademark of National Semiconductor Corporation.
© 2008 National Semiconductor Corporation 300578
www.national.com