- Output short-circuit protection
- Thermal overload protection
- Stereo filterless Class D operation
- Spread Spectrum Modulation
- Grounding reference headphone driver
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I 2 C control interface
- 32-step input volume control
- Output volume control
- Minimal external components
- Click inhibition
- Micropower shutdown
- Space-saving 36-bump μSMD packages available
- Single power supply
- RF suppression
illustrate
LM49250 audio subsystem designed for a fully integrated stereo phone application. LM49250 combines 45mW/Ch stereo ground with a 2.4W/Ch stereo Class D speaker amplifier, headphone amplifier, Class AB headphone amplifier, national 3D boost, volume control, input mixer referenced to a single device. 无滤波器D类放大器可为8Ω负载
LM49250 features a new circuit technology that uses a charge pump to generate a negative supply voltage. This results in a bias in the output of the headphones, eliminating the output coupling capacitor.
To improve anti-interference, LM49250 functions are fully differential left, right and mono inputs. Three inputs that can mix/duplicate output combinations from any speaker, headphone, or earpiece amplifier. Left, right differential inputs can be used as independent single-ended inputs for multiple stereo audio sources to mix. Mixer, volume control and device mode selection control, via I 2 C compatible interface.
Output short-circuit and thermal overload protection prevent damage to equipment under fault conditions. Advanced click suppression eliminates audible transient noise when power-up/down and off.
Key specifications:
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■ Power output at V DD = 5V
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Speakers: R L =4Ω，THD + N ≤ 1％ R L =4Ω，THD + N ≤ 10％ R L =8Ω，THD + N ≤ 1％
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1.97W/Ch 2.4W/Ch 1.2W/Ch
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Earphone: R L =16Ω，THD + N ≤ 1％ R L =32Ω，THD + N ≤ 1％
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41mW/Ch 45mW/Ch
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Receiver: R L =16Ω，THD + N ≤ 1％ R L =32Ω，THD + N ≤ 1％
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170mW 90MW
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■ Turn off the current
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0.1μA |
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■ At 5V, the efficiency is 8Ω 1W
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87％ |
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■ At 3.6V, the efficiency of 500mW is 8Ω
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85％ |
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- mobile phone
- Portable navigation device
- Portable media player
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