Capacitive touch control system with frequency booster
AssigneePixart Imaging Inc.
InventorSung-Han Wu
Life of this patent
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Abstract
There is provided a capacitive touch control system adapted to detect low frequency signals, including a touch panel and an analog front end. The analog front end includes a frequency booster, which boosts a low frequency signal outputted by the touch panel using a variable reference frequency corresponding to different function symbols of the low frequency signal such that resistance of a resistor of an amplifier in the analog front end needs not to be increased thereby reducing the manufacturing cost and a leakage voltage drop on the resistor.
Claims17
A capacitive touch control system, comprising:
- a touch panel;
- an analog front end, configured to receive a low frequency signal from the touch panel, and comprising:
- a frequency booster, configured to perform frequency adjustment on the low frequency signal using a reference frequency, wherein when the touch panel is touched by a touch pen, the reference frequency is controlled to be variable;
- an operational amplifier, coupled to an output of the frequency booster, and having an inverting input end coupled to the frequency booster and a non-inverting input end;
- and
- a gain capacitor coupled between the frequency booster and the inverting input end of the operational amplifier.
A capacitive touch control system, comprising:
- a touch panel;
- an analog front end, configured to receive a low frequency signal from the touch panel, and comprising:
- a frequency booster, configured to perform frequency adjustment on the low frequency signal using a reference frequency;
- an operational amplifier, coupled to an output of the frequency booster, and having an inverting input end coupled to the frequency booster and a non-inverting input end;
- and
- a gain capacitor coupled between the frequency booster and the inverting input end of the operational amplifier, wherein
- when the low frequency signal is received by the analog front end in at least one interval, the reference frequency is controlled to be variable, and
- when the low frequency signal is not received by the analog front end in at least one interval, the reference frequency is controlled to be constant.
A capacitive touch control system, comprising:
- a touch panel;
- an analog front end, configured to receive a low frequency signal, which comprises multiple signal frequencies and multiple blank intervals each between two signal frequencies, from the touch panel, and comprising:
- a frequency booster, configured to perform frequency adjustment on the low frequency signal using a reference frequency, wherein
- when the multiple signal frequencies of the low frequency signal is received by the analog front end, the reference frequency is controlled to be variable, and
- the reference frequency is controlled to be constant within the multiple blank intervals.
Dependencies are inferred from the claim text.