- Spread spectrum architecture reduces EMI
- Mono class D work
- No output filter required for inductive loads
- Externally set gain
- Very fast start-on time: 17 μs (typical)
- Minimal external components
- "Click" sound suppression circuit
- Micropower shutdown mode
- Space-saving 0.5mm pitch micro SMD and LLP packages
illustrate
The LM4675 is a single-supply, high-efficiency, 2.65W, mono, Class-D audio amplifier. The spread-spectrum, filter-free PWM architecture reduces EMI and eliminates output filters, reducing the number of external components, board area consumption, system cost, and simplifying design.
The LM4675 is designed to meet the needs of mobile phones and other portable communication devices. Operating on a 5V single supply supply, it is capable of driving less than 1% THD+N4Ω speaker load at 2.2W continuous average output Its flexible power requirements allow operation from 2.4V to 5.5V. The broadband propagation LM4675 spectrum architecture reduces EMI radiation due to the frequency of the modulator.
Compared to the LM4675, a typical Class AB amplifier is more efficient than a speaker load. With a 3.6V power supply driving an 8Ω speaker, the IC has an efficiency of 80% at 100mW and 89% of the output power at 400mW.
LM4675 features a low-power downtime mode. Shutdown can enable the drive shutdown pin to Logical Low (GND).
The LM4675's gain is an external configuration that allows independent gain control by summarizing signals from multiple sources. Output short-circuit protection and thermal overload protection prevent damage to equipment under fault conditions.
Key specifications:
■ The efficiency is 3.6V, 400mW 8Ω speakers
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89% (typical)
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■ The efficiency is 3.6V, 100mW 8Ω speakers
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80% (typical)
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■ The efficiency is in 5V, 1W to 8Ω speakers
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89% (typical)
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■ Quiescent current, 3.6V power supply
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2.2 mAh (typical)
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■ Turn off the power completely Supply current
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0.01μA (typical)
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■ Single supply voltage range
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2.4V to 5.5V
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■ PSRR, F = 217Hz
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82 dB
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apply
- mobile phone
- handheld computer
- Portable electronic devices
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