Touch sensing method and associated circuit
First Claim
1. A display controller fabricated on a semiconductor substrate, comprising:
- a touch control circuit configured to detect whether a contact point is touched; and
a pulse width modulation (PWM) circuit coupled to the touch control circuit and a lighting module, the PWM circuit configured to generate a PWM signal that controls operations of the lighting module,wherein the touch control circuit is configured to receive an image synchronous signal, andwherein, in response to receiving the image synchronous signal, the touch control circuit is configured to trigger the PWM circuit to generate the PWM signal.
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Accused Products
Abstract
A touch sensing method and associated circuit are provided. In one aspect, a touch control circuit includes a first current source, a second current source, a plurality of switches, a hysteresis comparator, a frequency divider and a flip-flop. The switches are couple to a plurality of external contact points. The hysteresis comparator is coupled to a first reference comparison voltage and a second reference comparison voltage. Each of the external contact points is selectively coupled to an input terminal of the hysteresis comparator through the switches. The first current source and the second current source are coupled to the input terminal of the hysteresis comparator to generate a sensing voltage. The hysteresis comparator compares the sensing voltage with the first reference comparison voltage and the second reference comparison voltage to generate a hysteresis comparison output to control the first current source or the second current source.
15 Citations
16 Claims
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1. A display controller fabricated on a semiconductor substrate, comprising:
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a touch control circuit configured to detect whether a contact point is touched; and a pulse width modulation (PWM) circuit coupled to the touch control circuit and a lighting module, the PWM circuit configured to generate a PWM signal that controls operations of the lighting module, wherein the touch control circuit is configured to receive an image synchronous signal, and wherein, in response to receiving the image synchronous signal, the touch control circuit is configured to trigger the PWM circuit to generate the PWM signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A touch sensing method applied to a display controller fabricated on a semiconductor substrate, the method comprising:
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receiving, by a touch control circuit, an image synchronous signal; providing, by the touch control circuit in response to receiving the image synchronous signal, a synchronous signal to a pulse width modulation (PWM) circuit coupled to the touch control circuit; controlling, by the PWM circuit, operations of a lighting module in response to receiving the synchronous signal from the touch control circuit; and determining, by the touch control circuit, whether a contact point is touched. - View Dependent Claims (11, 12, 13, 14)
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15. A touch control circuit as an integrated part of a display controller, the touch control circuit comprising:
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a first current source configured to receive and operate according to a control signal; a second current source configured to receive and operate according to the control signal; a plurality of switches coupled to a plurality of external contact points; and a hysteresis comparator, coupled to a first reference comparison voltage and a second reference comparison voltage, and selectively coupled to one of the external contact points through the switches, the hysteresis comparator having an input terminal coupled to the first current source and the second current source to generate a sensing voltage, the hysteresis comparator configured to compare the sensing voltage with the first reference comparison voltage and the second reference comparison voltage to generate a hysteresis comparison output as the control signal to control operations of the first current source and the second current source. - View Dependent Claims (16)
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Specification