Features
| • | Output Short Circuit Protection |
| • | Stereo Class D operation |
| • | No output filter required |
| • | Logic selectable gain |
| • | Independent shutdown control |
| • | Minimum external components |
| • | Click and Pop suppression |
| • | Micro-power shutdown |
| • | Available in space-saving 2mm x 2mm x 0.6mm micro SMD, and 4mm x 4mm x 0.8mm LLP packages |
Description The LM4674 is a single supply, high efficiency, 2.5W/channel, filterless switching audio amplifier. A low noise PWM architecture
eliminates the output filter, reducing external component count, board area consumption, system cost, and simplifying design.
The LM4674 is designed to meet the demands of mobile phones and other portable communication devices. Operating from a single
5V supply, the device is capable of delivering 2.5W/channel of continuous output power to a 4Ω load with less than 10% THD+N.
Flexible power supply requirements allow operation from 2.4V to 5.5V.
The LM4674 features high efficiency compared to conventional Class AB amplifiers. When driving an 8Ω speaker from a 3.6V
supply, the device features 85% efficiency at PO = 500mW. Four gain options are pin selectable through the G0 and G1 pins.
Output short circuit protection prevents the device from being damaged during fault conditions. Superior click and pop suppression
eliminates audible transients on power-up/down and during shutdown. Independent left/right shutdown control maximizes power
savings in mixed mono/stereo applications.
Key Specification
| ■
Efficiency at 3.6V, 100mW into 8Ω
|
80% (typ)
|
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Efficiency at 3.6V, 500mW into 8Ω
|
85% (typ)
|
| ■
Efficiency at 5V, 1W into 8Ω
|
85% (typ)
|
| ■
Quiescent Power Supply Current
at 3.6V supply
|
4mA
|
| ■
Power Output at VDD = 5V,
RL = 4Ω, THD
≤ 10%
|
2.5W (typ)
|
| ■
Power Output at VDD = 5V,
RL = 8Ω, THD
≤ 10%
|
1.5W (typ)
|
| ■
Shutdown current
|
0.03μA (typ)
|
Applications
| • | Mobile phones |
| • | PDAs |
| • | Laptops |
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