Method for improving EMC of keyboard soft board
AssigneeSilitek Corporation
InventorBright Huang
Life of this patent
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Abstract
A method for improving the EMI compatibility of the keyboard soft board is disclosed. A low-pass filter is installed on the scan lines of the keyboard soft board to remove high-frequency noise signals produced by the soft board circuit, achieving the EMC requirement. The low-pass filter is formed between the input terminal of the scan line and the touch pad. An inductance is selectively installed and between the touch pads. A capacitance is formed between the touch pad of the scan line and a ground network. The method of forming the capacitance is to form ground pads on the ground network corresponding the scan line touch pads. The method of forming the inductance may be achieved through a reversed U-shaped inductor.
Claims16
A method for improving EMC (Electromagnetic Compatibility) of a keyboard soft board, which comprises the steps of providing a low-pass filter for each of a plurality of scan lines in the layout of the keyboard soft board;
- wherein the low-pass filter of each of the scan lines consists of more than one inductor connected in series and more than one capacitor connected in parallel, the inductors in series being installed between touch pads of each scan line and between the first touch pad and the input terminal of the scan line, and the capacitors being installed between the touch pad of each scan line and a ground network of the keyboard soft board.
A method for improving the EMC of a keyboard soft board, which comprises the steps of arbitrarily selecting more than one scan lines from a plurality of scan lines of the keyboard soft board and designing a low-pass filter for each of them;
- wherein the low-pass filter of each of the scan lines consists of more than one inductor connected in series and more than one capacitor connected in parallel, the inductors in series being installed between touch pads of each scan line and between the first touch pad and the input terminal of the scan line, and the capacitors being installed between the touch pad of each scan line and a ground network of the keyboard soft board.
Dependencies are inferred from the claim text.