Patents Assigned to Holtek Semiconductor
  • Patent number: 8004447
    Abstract: The configuration of a successive approximation analog to digital converter (ADC) and a method thereof are provided in the present invention. The proposed configuration includes a comparator having an inverting input terminal, a non-inverting input terminal and an output terminal outputting a comparison result, a most significant bit ADC coupled to the non-inverting input terminal, and a least significant bit ADC coupled to the inverting input terminal.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: August 23, 2011
    Assignee: Holtek Semiconductor
    Inventor: Pochin Hsu
  • Patent number: 7541877
    Abstract: An auto-adjusting high accuracy oscillator is disclosed, which comprises: a frequency comparator, for comparing a synchronization signal obtained from a USB host with an oscillation signal obtain from a device; a control tuning circuit, further comprising a counter and an adder/sub circuit; and an oscillating element; wherein a variation is obtained by the counting of the counter while transmitting the variation to the adder/sub circuit to be encoded thereby into a digital code so as to enable the oscillating element to perform a frequency up/down operation accordingly for approaching the synchronization signal successively.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: June 2, 2009
    Assignee: Holtek Semiconductor
    Inventors: Chih Wei Yang, Chien Hsun Lee, Hsiang Sheng Liu, Quan Xing Huang
  • Patent number: 7415546
    Abstract: The invention relates to an apparatus for interfacing a peripheral device corresponding to the detection of interface, which comprises: a regulator, for regulating the working voltage of the circuit of the apparatus; an USB physical layer with switch controller, for detecting and determining whether the interface to which the peripheral device is connected is an USB interface and thus being capable of enabling an USB mode of the apparatus; at least four pull-high switch resistors; and an analog switch, capable issuing an analog signal while the apparatus is in the USB mode; wherein the PS2 mode of the apparatus is enabled while the USB physical layer with switch controller detects no USB interface being connected to the peripheral device, and the mode of the apparatus is controlled by the interaction of the on/off statuses of the four pull-high switch resistors.
    Type: Grant
    Filed: November 4, 2005
    Date of Patent: August 19, 2008
    Assignee: Holtek Semiconductor
    Inventors: Hsiang Sheng Liu, Pak Man Ma
  • Patent number: 7312589
    Abstract: 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. PPG0 and PPG1, 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 PPG0 and the PPG1 according to the alternative manner defined by the transition frequency of the PFD.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: December 25, 2007
    Assignee: Holtek Semiconductor
    Inventors: Yuan-Ho Liu, Chun-Hsiung Chen
  • Patent number: 7283000
    Abstract: An auto-adjusting high accuracy oscillator is disclosed, which includes: a frequency comparator, for comparing a synchronization signal obtained from a USB host with an oscillation signal obtain from a device; a control tuning circuit, further comprising a counter and an adder/sub circuit; and an oscillating element; wherein a variation is obtained by the counting of the counter while transmitting the variation to the adder/sub circuit to be encoded thereby into a digital code so as to enable the oscillating element to perform a frequency up/down operation accordingly for approaching the synchronization signal successively.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: October 16, 2007
    Assignee: Holtek Semiconductor
    Inventors: Chih Wei Yang, Chien Hsun Lee, Hsiang Sheng Liu, Quan Xing Huang
  • Patent number: 7271372
    Abstract: 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.
    Type: Grant
    Filed: August 10, 2005
    Date of Patent: September 18, 2007
    Assignee: Holtek Semiconductor
    Inventors: Yuan-Ho Liu, Chun-Hsiung Chen, Chun-Ku Lin