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.
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 DSBGA, and 4mm x 4mm x 0.8mm WQFN Packages
## Key Specifications
Efficiency at 3.6V, 100mW into 8Ω: 80% (typ)
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%: 2.5 W (typ)
Shutdown Current: 0.03μA (typ)
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