Holtek Semiconductor Corp.

Signal Electronic Co., Ltd.

Chun-Hsiung Chen

Yuan-Ho Liu

Chun-Ku Lin

Wen-Liang Liu

Ting-Chi Lee

Sheng-Ho Wang

A signal processing method is provided and includes the following steps. A first synchronizing signal having a synchronizing frequency and a next expected pulse with an expected rising edge is provided. A second synchronizing signal having a selected frequency being within a frequency range is produced when the synchronizing frequency of the first synchronizing signal is out of a frequency range. A third synchronizing signal having a first pulse with a first rising edge is produced when the synchronizing frequency is within the frequency range, wherein the first rising edge is produced at an expected time point. Whether the next expected pulse appears in a period from the expected time point to a certain time point is detected as a detecting result. And a first falling edge of the first pulse is produced based on the detecting result. A picture-field flicker phenomenon of an LCD is eliminated through the method.

Signal processing circuit and method

An input offset voltage corrector used in an operational amplifier includes a switch unit, a register unit, an offset voltage correction unit and a micro control unit. The micro control unit sets the register unit to control the switch unit to switch the input offset voltage corrector to different operating modes. If an input offset voltage corrector is set to the offset voltage correcting mode, the offset voltage correction unit will adjust the input offset voltage of the operational amplifier to output an exact signal. Furthermore, the input offset voltage corrector can adjust the input offset voltage anytime according to the operating conditions to maintain the best characteristic of the operational amplifier.

Input offset voltage corrector

A method of power control apparatus for electric cookers is provided. In the method, a micro controller unit (MCU) with a programmer pulse generator (PPG) and analog/digital (AID) converters is utilized, wherein a command can be inputted externally to the MCU for restarting or stopping the output of the PPG; and the PPG is capable of outputting pulses of programmable pulse width, being programmed by software for power control and, also, the protection of power control apparatus.

Power control apparatus and method for electric cookers

A driver control circuit and method for a cold cathode fluorescent lamp (CCFL), that the driver control circuit comprises: at least a comparator; at least an input/output port, at least an analog-to-digital converter; at least two programmable pulse generators (PPGs), including a first programmable pulse generator and a second programmable pulse generator, i.e. PPGand PPG, being activated for generating pulse signals in an alternative manner for driving the CCFL; at least a programmable frequency divider (PFD), capable of programming the output thereof to be used as the control signal for activating the PPGand the PPGaccording to the alternative manner defined by the transition frequency of the PFD.

Driver control circuit and method for cold cathode fluorescent lamp

A power control apparatus for electric cookers includes an input unit, an output unit, a micro controller unit (MCU), having a programmer pulse generator (PPG) and at least an analog/digital converter built therein, a power circuit, an exciter-coil circuit, an output circuit of insulated gate bipolar transistor (IGBT), and a drive circuit of insulated gate bipolar transistor (IGBT). A command can be inputted externally to the MCU for restarting or stopping the output of the PPG and the PPG is capable of outputting pulses of programmable pulse width.

The method and the device thereof for dynamically calibrating a frequency is provided. The method includes steps of: (a) providing a first system frequency; (b) obtaining a first parameter of timer counting number; (c) providing a second system frequency; (d) obtaining a second parameter of timer counting number if there is a frequency drift between said first system frequency and said second system frequency; (e) obtaining a third parameter of timer interrupt interval by comparing said first parameter of timer counting number with said second parameter of timer counting number; and (f) calibrating a frequency output according to said third parameter of timer interrupt interval.

Growing community of inventors

Hsinchu, Taiwan

Chun-Hsiung Chen