- 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
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Space-saving 0.4mm pitch micro SMD and LLP TM pack
illustrate
The LM4673 is a single-supply, high efficiency, 2.65W, mono, Class D audio amplifier. Low-noise, filter-free PWM architecture, no output filters, reduces external component count, board area consumption, system cost, and simplifies design.
The LM4673 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 2.1W Its flexible power requirements allow operation from 2.4V to 5.5V.
Compared to the LM4673, a typical Class AB amplifier is loaded with high efficiency with a speaker. When an 8Ω speaker is driven with a 3.6V supply, the IC has an efficiency of 80% at a power level of 100mW and 88% of the output power of 400mW.
The LM4673 has a low-power shutdown mode. Shutdown enables the drive shutdown pin to be logic low (GND).
The gain of the LM4673 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
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■ The 3.6V, 400mW efficiency is an 8Ω speaker
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88% (typical)
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■ At 3.6V efficiency, 100MW to 8Ω speakers
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80% (typical)
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■ 5V, efficiency is 8Ω speaker 1W
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86% (typical)
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■ Quiescent current, 3.6V supply
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2.1 mA (typical)
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■ Total shutdown 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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78 dB
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apply
- mobile phone
- Pocket PC
- Portable electronic devices
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