Patents by Inventor Yeong-Chang Ahn

Yeong-Chang Ahn has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6144596
    Abstract: A semiconductor memory test apparatus includes a test signal input unit for externally receiving a test word line model signal and a test column address pulse enable signal, which are used for a memory operation in the test mode. The test apparatus also includes a test mode setting unit that receives: a row address strobe bar signal, a column address strobe bar signal, a write enable bar signal and an address signal, and that generates first and second test mode setting signals. A first switching unit switches a signal input from a row address path circuit or from the test signal input unit, in accordance with a first test mode setting signal. A second switching unit switches another signal input from the row address path circuit or from the test signal input unit in accordance with a second test mode setting signal, and outputs the switched signal to the column address path circuit.
    Type: Grant
    Filed: November 10, 1998
    Date of Patent: November 7, 2000
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Yeong Chang Ahn
  • Patent number: 6094389
    Abstract: A semiconductor memory apparatus having a refresh test circuit provided with a control unit, a write control unit, a row address buffer and column address buffer, a refresh address counter, a refresh control unit, a column decoder, a data input/output buffer, a plurality of sense amplifier arrays and a plurality of memory cell arrays, includes a refresh test control unit for receiving an address signal by the control of the control unit and controlling the refresh control unit, the row block decoder and the plurality of sense amplifier arrays. The apparatus screens refresh-related poor products by efficiently applying a disturb refresh test during a short period of time.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: July 25, 2000
    Assignee: Hyundai Micro Electronics Co., Ltd.
    Inventor: Yeong-Chang Ahn
  • Patent number: 6092223
    Abstract: A redundancy circuit for a semiconductor integrated circuit is disclosed, which includes each cell of the column redundancy cell block corresponding to each cell of the cell sub-array is connected opposite to the connection of the cells of the cell sub-array, wherein a state that an electric charge corresponding to a data written into each cell of the cell sub-array and the column redundancy cell block is discharged, is measured for thus accurately checking the position of the repaired cell after the redundancy operation is performed.
    Type: Grant
    Filed: May 27, 1998
    Date of Patent: July 18, 2000
    Assignee: LG Semicon Co., Ltd.
    Inventor: Yeong-Chang Ahn
  • Patent number: 5539702
    Abstract: A test apparatus for a semi-conductor memory device comprising a memory section having a plurality of memory cell arrays, the memory cell arrays receiving input data in parallel, a latch control circuit responsive to a write enable signal and an address signal for outputting a control signal for latching the input data while the input data is written into the memory section, an expected data latch circuit responsive to the control signal from the latch control circuit and a read enable signal for latching the input data while the input data is written into the memory section and outputting the resultant expected data, a clock generator for generating a clock signal in response to a test flag signal and an internal column address select signal, an expected data transfer circuit for transferring the expected data from the expected data latch circuit in response to the test enable signal and the read enable signal, a data discrimination circuit for discriminating whether output data from the memory section are t
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: July 23, 1996
    Assignee: Goldstar Electron Co., Ltd.
    Inventor: Yeong-Chang Ahn