Invention Grant
US09345083B2 Boost converter with a pulse frequency modulation mode for operating above an audible frequency
有权
具有脉冲频率调制模式的升压转换器,用于在可听频率之上操作
- Patent Title: Boost converter with a pulse frequency modulation mode for operating above an audible frequency
- Patent Title (中): 具有脉冲频率调制模式的升压转换器,用于在可听频率之上操作
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Application No.: US14503037Application Date: 2014-09-30
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Publication No.: US09345083B2Publication Date: 2016-05-17
- Inventor: Asif Hussain , Behzad Mohtashemi , Mohammad J. Navabi-Shirazi , Jingdong Chen , Manisha P. Pandya
- Applicant: Apple Inc.
- Applicant Address: US CA Cupertino
- Assignee: Apple Inc.
- Current Assignee: Apple Inc.
- Current Assignee Address: US CA Cupertino
- Agency: Downey Brand LLP
- Main IPC: H05B37/02
- IPC: H05B37/02 ; H05B33/08 ; G09G3/34

Abstract:
The embodiments discussed herein relate to systems, methods, and apparatus for executing a pulse frequency modulation (PFM) mode of a boost converter in order to ensure that a switching frequency of the boost converter is a above an audible frequency threshold. In this way, a user operating a display device that is controlled by the boost converter will not be disturbed by audible noises generated at the display device. The PFM mode enforces an audible frequency threshold by using control circuitry designed to increase or decrease the frequency of a pulse signal depending on how the frequency of the pulse signal changes over time. The control circuitry can apply an additional load to the boost converter in order to increase the frequency of the pulse signal when the frequency is approaching the audible frequency threshold.
Public/Granted literature
- US20150115813A1 BOOST CONVERTER WITH A PULSE FREQUENCY MODULATION MODE FOR OPERATING ABOVE AN AUDIBLE FREQUENCY Public/Granted day:2015-04-30
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