Multi mode bias modulator operating in envelope tracking mode or average power tracking mode and envelope tracking power amplifier using the same
US-9425744-B2 · Aug 23, 2016 · US
System and method of reducing click and pop noise in audio playback devices
US9014396B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-9014396-B2 |
| Application number | US-2385408-A |
| Country | US |
| Kind code | B2 |
| Filing date | Jan 31, 2008 |
| Priority date | Jan 31, 2008 |
| Publication date | Apr 21, 2015 |
| Grant date | Apr 21, 2015 |
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- Title
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Abstract
Official abstract text for this publication.
An audio system that reduces or eliminates click and pop noise during power up and power down operations. In particular, the audio system includes an amplifier with an input adapted to receive an input audio signal and an output adapted to produce an amplified output audio signal for an associated speaker. The audio system further includes a noise reduction circuit adapted to smoothly apply and remove a DC voltage to and from the output of the amplifier in a manner that reduces or eliminates click and pop noise from being generated by the associated speaker. The DC voltage at the output of the amplifier may be derived from a DC reference voltage source and/or from the input audio signal.
First claim
Opening claim text (preview).
What is claimed is: 1. An audio system, comprising: an amplifier including an input adapted to receive an input audio signal and an output adapted to produce an output audio signal; and a noise reduction circuit adapted to generate a ramp control voltage exhibiting a substantially ramping waveform to control a continuously variable resistance device through which a substantially smooth rising DC voltage is applied to the output of the amplifier during a power up operation in a m…
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Electricity · mapped topic
Electricity · mapped topic
- H03F1/305Primary
Electricity · mapped topic
Electricity · mapped topic
Electricity · mapped topic
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Frequently asked questions
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- What does patent US9014396B2 cover?
- An audio system that reduces or eliminates click and pop noise during power up and power down operations. In particular, the audio system includes an amplifier with an input adapted to receive an input audio signal and an output adapted to produce an amplified output audio signal for an associated speaker. The audio system further includes a noise reduction circuit adapted to smoothly apply and…
- Who is the assignee on this patent?
- Miao Guoqing, Qualcomm Inc
- What technology area does this patent fall under?
- Primary CPC classification H03F1/305. Mapped technology areas include Electricity.
- When was this patent published?
- Publication date Tue Apr 21 2015 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).