Mediatek Corporation

Industrial Technology Research Institute

Hung-I Chen

Chih-Hong Lou

Yen-Hsun Hsu

Sung-Han Wen

Yen-Lin Chen

Wei-Cheng Tang

Ming-Jiou Yu

Kuan-Kai Juan

Hao-Hui Yin

Jiun-Lang Huang

Shiue Shin Liu

Xuan-Lun Huang

Hung-Yen Chen

Chih-Chuan Chen

Chih-Lung Tai

Chien Wei Kuan

Chang-Yu Chen

An electronic circuit is provided. An error amplifier comprises a first input terminal coupled to a reference voltage, a second input terminal coupled to a feedback voltage, and a transistor comprises a first terminal coupled to an input voltage, a control terminal coupled to an output terminal of the error amplifier and a second terminal outputting an output voltage. A switching-capacitor circuit is coupled between the output voltage and the error amplifier and comprises a plurality of switching elements and at least first and second capacitors. The switching elements are switched by non-overlapping clocks such that the second capacitor is discharged to a bias voltage during a first period, and the first and second capacitors are connected together during a second period thereby extracting a division voltage from the output voltage to serve as the feedback voltage.

Voltage regulator having a plurality of capacitors configured to obtain a feedback voltage from a division voltage

A controller chip for controlling a motor device includes a first input port, a first output port, a controller, and a signal processing circuit. The first input port is arranged to receive a motor control input. The first output port is arranged to generate a motor control output. The controller is arranged to generate an output signal according to an input signal, and has a second input port for receiving the input signal and a second output port for outputting the output signal. The input signal is derived from the motor control input, and the motor control output is derived from the output signal. The signal processing circuit has a target interconnection configuration selected from a plurality of candidate interconnection configurations each including an interconnection between the first input port and the second input port and an interconnection between the first output port and the second output port.

Controller chip with signal swapping capability for controlling motor device and related method thereof

A method and an apparatus for evaluating weighting of elements of a DAC and a SAR ADC using the same are provided. An equivalent weighting of each composed element is obtained by adding a reference element with a reference weighting, an auxiliary DAC, and a search circuit into the SAR ADC, and the equivalent weighting is represented by the reference weighting. The SAR ADC can calculate and then obtain a correct digital output by using the calibrated equivalent weighting and the successive approximation result of each input signal. The present disclosure prevents the necessity of matching each composed element of the DAC in the SAR ADC.

Method and apparatus for evaluating weighting of elements of DAC and SAR ADC using the same

A touch screen digitizing system comprising a touch screen unit and an analog to digital converter. The touch screen unit includes a first resistive sheet with opposing first and second terminals and a second resistive sheet with opposing third and fourth terminals. The first and second resistive sheets are alternatively energized through the first, second, third, and fourth terminals. The analog to digital converter has an input coupled to the third terminal when the first resistive sheet is energized and the second resistive sheet is not, and coupled to the first terminal when the second resistive sheet is energized and the first resistive sheet is not, a first reference terminal dynamically coupled to a first reference voltage, a second reference terminal dynamically coupled to the second reference voltage, and an output terminal providing digital output data.

Touch screen measurement circuit and method

A DC-coupled audio out unit is provided, including at least one regulator and at least one audio amplifier. The regulator is coupled to at least one power terminal of the audio amplifier.

Audio out unit

Voltage regulators are provided. In one embodiment of the voltage regulators, a differential amplifier receives a reference voltage and a feedback voltage, to generate a control signal according to a voltage difference between the feedback voltage and the reference voltage. An output transistor has a first terminal coupled to a power voltage, a control terminal coupled to the differential amplifier for receiving the control signal, and a second terminal coupled to an output terminal. A voltage feedback circuit is coupled between the output terminal and a ground voltage to generate the feedback voltage. A discharge transistor has a first terminal coupled to the ground voltage, a control terminal coupled to a first control signal, and a second terminal coupled to the output terminal through a first resistor in the voltage feedback circuit.

Voltage regulators

A switching regulator. A pulse width modulation (PWM) unit comprises an output stage and generates a PWM driving signal to control the output stage, such that an inductor delivers an inductor current signal to the load, and a slope compensation unit outputs a slope compensation signal with a compensation slope proportional to a falling slope of the inductor current signal to the PWM unit according to the inductor current signal.

Switching regulators

A capacitor array comprising a plurality of unit capacitors, each having first and second electrode plates. The first electrode plates are commonly connected via first routings. The second electrode plates are grouped and connected to a plurality of nodes via second routings. The second routings connected to one node and another do not overlap in the capacitor array. The second electrode plates connected to the same node conglomerate as a group and no second electrode plate connected to another node is located in the group.

Capacitor array management

A voltage regulating circuit for providing a regulated output voltage. The voltage regulating circuit includes a voltage regulator, a converting circuit, a capacitive device, a first current mirror module, and a second current mirror module. The voltage regulator has a first output producing the regulated output voltage and a second output producing a pass voltage. The converting circuit converts the pass voltage into a first current and a second current passing through a first converting node and a second converting node respectively, where the first current charges/discharges the capacitive device. The first current mirror module has a first current mirror path coupled to the first converting node and a second current mirror path coupled to the second converting node. The second current mirror module has a first current mirror path coupled to the second converting node and a second current mirror path coupled to the first output.

Linear voltage regulating circuit with undershoot minimization and method thereof

A programmable/tunable active low-pass filter at least has the resistors, capacitors and shunt control means. It uses the resistor ladder that is structured with various fixed resistors to implement the shunt control means. The cut-off frequency of a filter is associated with the time constant, which is determined by equivalent resistance and equivalent capacitance value in the filter circuit; therefore, the filter of the present invention allowed users to fine tune the cut-off frequency linearly through the shunt control means when the variation of the environment or process parameters of manufacture cause the cut-off frequency drift, thus, the cut-off frequency can be kept in a constant value. The present invention also provides a means for programming the cut-off frequency to a desirous frequency value dependent upon the conditions of application within a big range. Thus, it can be used in many purposes widely with the same filter circuit.

Programmable/tunable active RC filter

A Miller-compensated amplifier, having an amplifier input and an amplifier output, comprises a first gain stage, a second gain stage, a third gain stage, and a capacitor. The first gain stage has the amplifier input as a first gain stage input thereto and a first gain stage output. The second gain stage has a second gain stage input, coupled to the first gain stage output, and a second gain stage output. The third gain stage has a third gain stage input, coupled to the second gain stage output, and provides an output voltage at the amplifier output. The capacitor is coupled between the amplifier output and the second gain stage input. The second gain stage amplifies a small signal part of a current received thereby and leaves a DC component thereof substantially the same.

Miller-compensated amplifier

A tuning loop which can tune the cut-off frequency of an active RC filter is disclosed. The cut-off frequency is determined by equivalent resistance and equivalent capacitance in an active RC filter, therefore, the tuning loop changes the equivalent resistance to tune the cut-off frequency. The time constant of the circuit is compared to see if it is equal to the applied preset time cycle after the equivalent resistance value is changed. The cut-off frequency of the filter is tuned to a preset value when the time constant in the circuit is equal to the applied preset time cycle, or the equivalent should be changed until the time constant equal to the applied preset time cycle. A precise result can be obtained after being tuned by tuning loop due to the each component of the tuning loop are operated in an environment which is equivalent to the active RC filter.

Frequency tuning loop for active RC filters

A programmable/tunable active low-pass filter at least has the resistors, capacitors and shunt control devices. It uses the linear property of the MOSFET to implement the shunt control devices. Based on the first-ordered linear analysis of the transfer function of the active-RC filter, it is found that the cut-off frequency of the active-RC filter can be tuned via the effective small-signal current controlled by the shunt control devices. Therefore, the filter of the present invention allowed users for fine tune the cut-off frequency linearly through the shunt control devices when the variation of the environment or procedure parameters of manufacture (i.e. thermo-effects) cause the cut-off frequency drift, thus, the cut-off frequency can be kept in a constant value. In addition, it needs the different cut-off frequency from the different application. The present invention also provides a device for programming the cut-off frequency to a desired frequency value dependent upon the conditions of application within a big range. Thus, the same filter circuit can be used in many purposes widely.

Growing community of inventors

Kaohsiung, Taiwan

Hung-I Chen