LM4903
LM4903 is 1 Watt Audio Power Amplifier manufactured by National Semiconductor.
Description
The LM4903 is an audio power amplifier primarily designed for demanding applications in mobile phones and other portable munication device applications. It is capable of delivering 1 watt of continuous average power to an 8Ω BTL load with less than 1% distortion (THD+N) from a 5VDC power supply. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external ponents. The LM4903 does not require output coupling capacitors or bootstrap capacitors, and therefore is ideally suited for mobile phone and other low voltage applications where minimal power consumption is a primary requirement. The LM4903 features a low-power consumption shutdown mode, which is achieved by driving the shutdown pin with logic low. Additionally, the LM4903 features an internal thermal shutdown protection mechanism. The LM4903 contains advanced pop & click circuitry which eliminates noise which would otherwise occur during turn-on and turn-off transitions. The LM4903 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, 8Ω j Power Output at 3.0V, 1% THD, 4Ω j Power Output at 3.0V, 1% THD, 8Ω j Shutdown Current
62d B 1.07W (typ) 525m W (typ) 390m W (typ) 0.1µA (typ)
Features n n n n n n n n Available in space-saving MSOP package Ultra low current shutdown mode BTL output can drive capacitive loads Improved pop & click circuitry eliminates noise during turn-on and turn-off transitions 2.0
- 5.5V operation No output coupling capacitors, snubber networks or bootstrap capacitors required Unity-gain stable External gain configuration capability
Applications n Mobile Phones n PDAs n Portable electronic devices
Typical Application
200467D3
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer ® is a registered trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation
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