- The spread spectrum architecture reduces EMI
- Mono class D works
- No output filter required for inductive loads
- Externally set the gain
- Very Fast Turn-On Time: 17μs 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, filterless PWM architecture reduces EMI and eliminates output filters, reducing external component count, 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 from a single 5V supply, it is capable of driving less than 1% THD+N4Ω speaker load with a continuous average output of 2.2W Its flexible power requirements allow operation from 2.4V to 5.5V. The LM4675 spectral architecture for wideband propagation reduces EMI emissions due to the frequency of the modulator.
Compared to the LM4675, a typical Class AB amplifier is loaded with high efficiency with a speaker. With a 3.6V supply driving an 8Ω speaker, the IC has an efficiency of 80% at a power level of 100mW and 89% of the output power of 400mW.
LM4675 function, low-power shutdown mode. Shutdown enables the drive shutdown pin to be logic low (GND).
The gain of the LM4675 is externally configured to allow independent gain control by summarizing signals from multiple sources. Output short-circuit protection and thermal overload protection prevent damage to the device under fault conditions.
Main 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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■ Efficiency in 5V, 1W to 8Ω speakers
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89% (typical)
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■ Quiescent current, 3.6V supply
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2.2 mA (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, when F = 217Hz
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82 dB
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apply
- mobile phone
- Pocket PC
- Portable electronic devices
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