Patents Assigned to Holtek Semiconductor
  • Publication number: 20060114242
    Abstract: A detection method for a touch-panel device having a touch pad electrically connected to at least m×n equivalent capacitors is provided, wherein m is a number of the equivalent capacitors on a specific one of rows and n is a number of the equivalent capacitors on a specific one of columns. The method includes steps of: (a) charging the m equivalent capacitors on the specific row to obtain m digital signals; (b) comparing potentials of the m digital signals and obtaining a relatively smallest potential as a standard value; (c) repeating the steps (a)˜(b) to obtain n the standard values for the m×n equivalent capacitors; (d) touching the touch pad; (e) scanning the touch pad to obtain at least a potential variation value relative to the standard value for the m equivalent capacitors on the specific row; and (f) comparing the standard value with the variation value to identify a touched point on the touch pad.
    Type: Application
    Filed: November 17, 2005
    Publication date: June 1, 2006
    Applicant: Holtek Semiconductor Inc.
    Inventor: Yi-Chan Lin
  • Patent number: 7005905
    Abstract: A circuit capable of providing stable timing clock includes: a step-down clamping circuit, an oscillating circuit, and a voltage potential-conversing circuit. The step-down clamping circuit that step down the input first voltage potential, and clamp to output second voltage, the oscillating circuit is coupled to the clamping circuit and is an oscillating circuit that takes the second voltage as a operating voltage to generate a first timing clock signal, which has a lower voltage potential. The voltage potential-conversing circuit is coupled to the oscillating circuit to convert the first timing clock signal into a second timing clock signal, which has a higher voltage potential. And it is a stable timing clock signal available for other system circuit.
    Type: Grant
    Filed: February 20, 2004
    Date of Patent: February 28, 2006
    Assignee: Holtek Semiconductor Inc.
    Inventors: Chi-Ho Hsu, Chi-Bing Chen, Hsan-Fong Lin, Chia-Lu Hsu
  • Patent number: 6982606
    Abstract: 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.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: January 3, 2006
    Assignee: Holtek Semiconductor Inc.
    Inventors: Chun-Hsiung Chen, Sheng-Ho Wang
  • Patent number: 6894570
    Abstract: The present invention is related to a fast frequency locking method and architecture realized by employing adaptive asymmetric charge-pump current mechanism, whose circuit is composed of elements such as: a pair of frequency-dependent main current sources, a pair of (rising, descending) frequency-dependent assistant current sources, a digital control circuit, a voltage controlled oscillator, an impedance, a sampling frequency sampled from output frequency of the voltage controlled oscillator, a fixed reference frequency and a phase detector, etc. The difference between the present invention and traditional charge-pump circuit is that the present invention had added at least one pair of frequency-dependent assistant current sources.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: May 17, 2005
    Assignee: Holtek Semiconductor Inc.
    Inventor: Fong-Lieh Liang
  • Patent number: 6876939
    Abstract: The present invention discloses wave frequency calibration method and device for remote controller, the device of the present invention comprises an oscillator for generating a base wave; a storage for storing a match value; a modifier for generating a modified signal; and a processor connected to the oscillator, the storage and the modifier, the processor change the match value until the modified signal disappear and store the most updated match value in the storage to assure the receiving end of the remote controller can receive the signal with correct frequency. Incorporating with a RC oscillator, the wave frequency calibration method and device for remote controller of the present invention will avoid the problem of the bias of wave, which enables the RC oscillator to be a oscillator that can be used commonly in a regular remote controller.
    Type: Grant
    Filed: November 26, 2003
    Date of Patent: April 5, 2005
    Assignee: Holtek Semiconductor Corp.
    Inventors: Rong-Dzung Tsai, Chao-Kuo Lee
  • Publication number: 20050046509
    Abstract: An high-frequency signal suppresser includes a resister, a first capacitor, a second capacitor, and a shaping circuit. A high-frequency signal inputted from the input terminal of the high-frequency signal suppresser is filtered by the resister, the first capacitor, and the second capacitor, and then shaped by the shaping circuit so as to generate a logic signal at the output terminal of the high-frequency signal suppresser.
    Type: Application
    Filed: February 18, 2004
    Publication date: March 3, 2005
    Applicant: Holtek Semiconductor Inc.
    Inventor: Chun-Hsiung Chen
  • Publication number: 20040257315
    Abstract: A method for sequentially driving light emitting diodes (LEDs) arranged in an array is provided. The method includes steps of a) electrically connecting anodes and cathodes of the LEDs to a ground; b) keeping the cathodes of a first part of the LEDs being electrically connected to the ground; c) increasing anode potentials of the LEDs to a first reference potential, and floating the cathodes of other parts of the LEDs simultaneously; d) supplying a current to the first part of the LEDs, and increasing cathode potentials of the other parts of the LEDs to a second reference potential simultaneously; and e) repeating the steps a)-d) for a second part of the LEDs. In which, the first part of the LEDs is arranged in a target row of the array and the second part of the LEDs is arranged in a row next to the target row.
    Type: Application
    Filed: February 18, 2004
    Publication date: December 23, 2004
    Applicant: Holtek Semiconductor Inc.
    Inventors: Min Kun Wang, Shih Ting Chang
  • Publication number: 20040246248
    Abstract: The invention is a power-saving method for driving light-emitting diode, and the device employing the method is a matrix display screen that comprises a driving circuit, a memory, and a light-emitting diode. When the display screen performs scanning process, one of the output data and the internal data of the memory is checked. If the data being checked is zero, the execution of scanning a predetermined row of the screen is postponed for one period so that no action is taken. Postponing will achieve a power-saving function for the display screen comprising the light-emitting diode.
    Type: Application
    Filed: December 11, 2003
    Publication date: December 9, 2004
    Applicant: Holtek Semiconductor Inc.
    Inventors: Jason Tsai, Shih-Ting Chang
  • Publication number: 20040201403
    Abstract: 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.
    Type: Application
    Filed: April 6, 2004
    Publication date: October 14, 2004
    Applicant: Holtek Semiconductor Inc.
    Inventors: Chun-Hsiung Chen, Sheng-Ho Wang
  • Publication number: 20040189402
    Abstract: The present invention is related to a fast frequency locking method and architecture realized by employing adaptive asymmetric charge-pump current mechanism, whose circuit is composed of elements such as: a pair of frequency-dependent main current sources, a pair of (rising, descending) frequency-dependent assistant current sources, a digital control circuit, a voltage controlled oscillator, an impedance, a sampling frequency sampled from output frequency of the voltage controlled oscillator, a fixed reference frequency and a phase detector, etc. The difference between the present invention and traditional charge-pump circuit is that the present invention had added at least one pair of frequency-dependent assistant current sources.
    Type: Application
    Filed: August 13, 2003
    Publication date: September 30, 2004
    Applicant: Holtek Semiconductor Inc.
    Inventor: Fong-Lieh Liang
  • Publication number: 20040143409
    Abstract: The present invention discloses wave frequency calibration method and device for remote controller, the device of the present invention comprises an oscillator for generating a base wave; a storage for storing a match value; a modifier for generating a modified signal; and a processor connected to the oscillator, the storage and the modifier, the processor change the match value until the modified signal disappear and store the most updated match value in the storage to assure the receiving end of the remote controller can receive the signal with correct frequency. Incorporating with a RC oscillator, the wave frequency calibration method and device for remote controller of the present invention will avoid the problem of the bias of wave, which enables the RC oscillator to be a oscillator that can be used commonly in a regular remote controller.
    Type: Application
    Filed: November 26, 2003
    Publication date: July 22, 2004
    Applicant: Holtek Semiconductor Corp.
    Inventors: Rong-Dzung Tsai, Chao-Kuo Lee
  • Patent number: 6653692
    Abstract: The present invention discloses a double access path mask read-only memory cell array structure, characterized in that the stored data is accessed simultaneously through two access paths disposed on both sides of a memory cell array structure. The reliability is improved since the value 0 or 1 stored in the data can be accessed through two paths and the operation speed is enhanced since the resistance in the conductive path from the sense amplifier to the ground is effectively reduced when accessing 0.
    Type: Grant
    Filed: April 3, 2002
    Date of Patent: November 25, 2003
    Assignee: Holtek Semiconductor Inc.
    Inventor: Jinn-Nan Kao
  • Publication number: 20030189846
    Abstract: The present invention discloses a double access path mask read-only memory cell array structure, characterized in that the stored data is accessed simultaneously through two access paths disposed on both sides of a memoery cell array structure. The reliability is improved since the value 0 or 1 stored in the data can be accessed through two paths and the operation speed is enhanced since the resistance in the conductive path from the sense amplifier to the ground is effectively reduced when accessing 0.
    Type: Application
    Filed: April 3, 2002
    Publication date: October 9, 2003
    Applicant: Holtek Semiconductor Inc.
    Inventor: Jinn-Nan Kao
  • Publication number: 20030179078
    Abstract: An identification data transmitting circuit for controlling a transmission of an identification data in radio frequency identification tag is provided. The transmitting circuit includes a clock circuit for respectively generating a series of clock signals for elements in the identification data transmitting circuit, an selecting circuit having a counter, a random numeral generator and a comparator for providing an enable signal by means of comparing outputs of the counter and the random numeral generator, and a memory device being electrically connected between the clock circuit and the selecting circuit for storing the identification data of radio frequency identification tag and receiving the enable signal of selecting circuit, so as to output the identification data.
    Type: Application
    Filed: August 30, 2002
    Publication date: September 25, 2003
    Applicant: HOLTEK SEMICONDUCTOR INC.
    Inventors: Eric Chen, Min-Kun Wang, Chieh-Yung Tu, Chien-Hsien Tsai, Shih-Ting Chang
  • Patent number: 6526536
    Abstract: An integrated circuit is disclosed which includes a start test mode circuit for generating a test mode start-up signal to cause the integrated circuit to enter a test mode, and an automatic reset circuit responsive to the test mode start-up signal for preventing the integrated circuit from erroneously entering a test mode during normal operation.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: February 25, 2003
    Assignee: Holtek Semiconductor Inc.
    Inventors: Jason Chen, Bao-Shiang Sun, Henry Fan
  • Patent number: 6211786
    Abstract: This invention relates to a battery-free circuit device for RF identifying tag. It is advantageous that the electric potential across the antenna coil induced by the change of the alternating magnetic field of the radio wave signals is independent of the modulational switching of the RF identifying tag during the positive half cycles when the antenna is receiving the radio wave signals from the card reader, and that the efficiency of the voltage-charging rectifier circuit remains constant when the data are delivered into the card reader. Furthermore, in this invention, the modulational amplitude of the signals is larger than that in the prior art, thus the propagating distance is longer and it shows better accuracy and reliability in data reading.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: April 3, 2001
    Assignee: Holtek Semiconductor Inc.
    Inventors: Jeng-Rern Yang, Tsung-Han Yang
  • Patent number: 6148418
    Abstract: An environment monitoring integrated circuit is provided that allows the boundaries of operating parameters to be conveniently modified. The present invention allows the hardware designer to easily change the temperature boundary of the computer operation, or the boundaries of the operating voltage, the operating temperature and the rotation speed of the fan. The present invention uses limit registers which provide a simple implementation for changing the boundaries of the operating parameters of the computer.
    Type: Grant
    Filed: June 22, 1998
    Date of Patent: November 14, 2000
    Assignee: Holtek Semiconductor Inc.
    Inventors: Min-Kun Wang, Fang-Diahn Guo, Wen-Ping Cheng, Chi-Ho Hsu
  • Patent number: 6104320
    Abstract: An input detection circuit includes a matrix of keys formed by the intersection of a plurality of columns of keys and a plurality of rows of keys, with a crossover capacitor connected across the intersecting row and column of one of the keys. The input detection circuit further includes circuits for generating a difference in voltage potential across the capacitor, and circuits responsive to the difference in voltage potential across the capacitor for generating a signal representative of the presence of the capacitor. By knowing which keys have been connected with a crossover capacitor, the processor of the telephone will also know what scan options have been programmed.
    Type: Grant
    Filed: January 23, 1998
    Date of Patent: August 15, 2000
    Assignee: Holtek Semiconductor Inc.
    Inventors: Shih-Ping Tu, Tyng-Yuan Luh
  • Patent number: 6084484
    Abstract: A programmable precise frequency divider cooperating with a low frequency crystal and an oscillating circuit is disclosed. The divider includes a low frequency oscillating circuit, a preset code memory, a programmable preset code loader, an adder, and a register. The programmable preset code loader loads and latches a preset code either from the preset code memory or a preset code input line coupled to an external data source. The latched preset code and the current value of the register are commonly supplied to the adder. The adder is used to sum up the latched preset code from the programmable preset code loader and the current value from the register and thereby supply a resultant value to the register. The register accumulates the resultant value from the adder to the oscillating signal from the oscillating circuit and then supplies a output clock signal with a required divided frequency.
    Type: Grant
    Filed: October 28, 1998
    Date of Patent: July 4, 2000
    Assignee: Holtek Semiconductor Inc.
    Inventors: Herman Chang, Yueh-Mei Hou
  • Patent number: 6034671
    Abstract: A photocoupling signal detection circuit for a computer mouse to simplify the design of circuit by tracking the slope change of input voltage waveform and produce a digital output which can detect the movement of computer mouse is disclosed. This signal detection circuit includes a comparator, a state decision circuit, an up/down counter, and a D/A converter. The comparator produces an up/down signal connected to the state decision circuit, then the up/down signal connected to the up/down counter to transfer the up/down signal into a digital signal output. The digital signal connected to a D/A converter for transferring into an analog signal, and the analog signal can be compared with the output signal of an phototransistor. According to the state of up/down signal, the state decision circuit determines if the phototransistor is turned on or turned off and outputs different state signals, based on its determination. The output state signal is further utilized for the detection of a computer mouse.
    Type: Grant
    Filed: December 5, 1997
    Date of Patent: March 7, 2000
    Assignee: Holtek Semiconductor Inc.
    Inventors: Wen-Ping Cheng, Min-Kun Wang, Fang-Diahn Guo, Chi-Ho Hsu