- Output short-circuit protection
- Stereo Class D operation
- No output filter is required
- Logic selects gain
- Independent shutdown control
- Minimal external components
- Click inhibition
- Micropower shutdown
- Save 2mm x 2mm x 0.6mm in available space in micro SMD and 4mm x 4mm x 0.8mm LLP packages
illustrate
The LM4674 is a single-supply, high efficiency, 2.5W/channel, filter switching audio amplifier. A low-noise PWM architecture eliminates the need for output filters, reducing external component count, board area consumption, system cost, and simplifying design.
The LM4674 is designed to meet the needs of mobile phones and other portable communication devices. The device operates from a single 5V supply and is capable of delivering less than 10% THD + N 2.5W/channel of continuous output power into a 4Ω load Flexible power requirements allow operation from 2.4V to 5.5V.
The LM4674 has high efficiency compared to conventional Class AB amplifiers. When driving an 8Ω speaker from a 3.6V power supply, the device functions,atP O = 500MW 85% efficiency. The four gain options are pin-selectable via the G0 and G1 pins.
Output short-circuit protection against damage to the device under fault conditions. Advanced click suppression eliminates power-up/down and audible transient noise when off. Independent left/right shutdown control hybrid mono/stereo applications maximize power savings.
Main specifications
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■ At 3.6V, 100mW has an efficiency of 8Ω
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80% (typical)
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■ At 3.6V, 500mW has an efficiency of 8Ω
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85% (typical)
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■ At 5V, the efficiency is 8Ω1W
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85% (typical)
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■ Quiescent supply current On 3.6V supply
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4 mAh
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■ In VDD= 5V output power, RL = 4Ω, total harmonic distortion ≤ 10％
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2.5W (typical)
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■ In VDD= 5V output power, RL = 8Ω, total harmonic distortion ≤ 10％
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1.5W (typical)
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■ Shutdown current
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0.03μA (typical)
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apply
- mobile phone
- Pocket PC
- laptop
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