ELAN Microelectronics | Date: 2015-04-16
A touch sensing apparatus includes an excitation source, a capacitor under test, a sampling circuit and a filter. The excitation source is used to generate an excitation signal having a first frequency. The capacitor under test is used to receive the excitation signal, and generate a sensing signal. The sampling circuit is used to sample the sensing signal to generate a digital output. The sampling circuit includes a pulse density modulation unit operating at a second frequency to generate the digital output, wherein the second frequency is higher than the first frequency. The filter is coupled to the pulse density modulation unit, and arranged to filter the digital output.
ELAN Microelectronics | Date: 2015-09-09
A scanning method and device of a single layer capacitive touch panel has a self and mutual capacitive scanning procedures. The single layer capacitive touch panel has multiple electrode groups and shielding units respectively formed between the two corresponding adjacent electrode groups. When the self capacitive scanning procedure is executed, a first driving signal is outputted to each of the electrode groups and each of the shielding units. A self capacitive sensing signal of the driven electrode group is received after then. When the mutual capacitive scanning procedure is executed, a second driving signal is outputted to each of the electrode group and each of the shielding unit is connected to a ground. A mutual capacitive sensing signal from each of the driven electrode groups is received after then. Therefore, the self capacitance value of the self capacitive sensing signal is not increased greatly since the shielding units are not connected to the ground.
ELAN Microelectronics | Date: 2015-10-29
A screen control module of a mobile electronic device has at least one controller formed on a circuit board. The circuit board has multiple solder pads formed on the circuit board and respectively aligning along a first direction and a second direction. An amount of the solder pads along the first direction is greater than that along the second direction. The controller is formed by an integrated circuit with a package, and the aspect ratio of the package is not less than 2. The package has multiple electrical contacts respectively aligning along a length direction and a width direction. Each electrical contact aligns with and is electrically connected to a corresponding solder pad. Accordingly, the screen control module mounted within a side frame of a display of the mobile electronic device can increase the aspect ratio to meet the demand for narrowing the side frame of the display.
ELAN Microelectronics | Date: 2015-08-13
The present invention is related to a capacitive touch device and excitation signal generating circuit and method thereof. The excitation signal generating circuit is connected to multiple sensing traces of the capacitive touch device, and has a storage unit storing at least one set of digital data. Each set of digital data is corresponding to a frequency. The PDM signal generator reads the set of digital data and converts the read set of digital data to a PDM signal according to the frequency of the read set of digital data. The PDM signal is recovered to an analog excitation signal since the PDM signal passes through a current transmission path, which is equivalent to a low pass filter. Therefore, the present invention can decrease a distortion of the sensing signal to increase accuracy of the sensing signal and to save power.
ELAN Microelectronics | Date: 2015-06-02
A transconductance amplifier mirror circuit is connected to an electrode for sensing the capacitance of the electrode with reference to ground, or the capacitance between the electrode and another electrode. A voltage level change is produced on the electrode connected to the transconductance amplifier mirror circuit to cause the transconductance amplifier mirror circuit to supply charges to or drain charges from a charge calculation circuit. The charge amount variation is converted to a signal for calculating the sensed capacitance.