Patents by Inventor Yun-Kee Lee
Yun-Kee Lee 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).
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Patent number: 8258764Abstract: The present invention relates to a driving device. The driving device according to the present invention includes a main transistor that supplies a current to a load by using a power supply, an auxiliary transistor that drops a predetermined voltage of the voltage of the power supply and transmits the dropped voltage to the main transistor in a turn-on state, and a bypass switch that transmits the voltage of the power supply to the main transistor when the auxiliary transistor is turned off.Type: GrantFiled: June 2, 2009Date of Patent: September 4, 2012Assignee: Fairchild Korea Semiconductor Ltd.Inventors: Kyoung-Min Lee, Yun-kee Lee, Duck-Ki Kwon, Ju-ho Kim, Eun-Chul Kang
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Publication number: 20090295358Abstract: The present invention relates to a driving device. The driving device according to the present invention includes a main transistor that supplies a current to a load by using a power supply, an auxiliary transistor that drops a predetermined voltage of the voltage of the power supply and transmits the dropped voltage to the main transistor in a turn-on state, and a bypass switch that transmits the voltage of the power supply to the main transistor when the auxiliary transistor is turned off.Type: ApplicationFiled: June 2, 2009Publication date: December 3, 2009Applicant: Fairchild Korea Semiconductor Ltd.Inventors: Kyoung-Min Lee, Yun-kee Lee, Duck-Ki Kwon, Ju-ho Kim, Eun-Chul Kang
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Patent number: 7453314Abstract: A temperature-independent current source is provided, which includes a current source generating a current that is proportional to the temperature and a current source generating a current that is inversely proportional to the temperature. Values of the circuit elements are selected so that the currents of the current sources add up to a substantially temperature-independent current. Related current sources utilize dual-base Darlington bipolar transistors to generate a temperature-independent current.Type: GrantFiled: June 5, 2006Date of Patent: November 18, 2008Assignee: Fairchild Korea Semiconductor, Ltd.Inventors: Jong-Tae Hwang, Dong-Hwan Kim, Yun-Kee Lee
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Patent number: 7432745Abstract: A high voltage gate driver circuit according to an embodiment of the present invention controls an operational range of an output signal of a level shifter to be appropriate for an operational range of a reshaper through a VIV converter. Even though the voltage range of the signal which is input from the high voltage gate driver circuit to the level shifter is different from the operational range of the reshaper, the input signal can always be recognized exactly regardless of the VTH voltage of the reshaper by controlling the operational range of the signal through the VIV converter. In addition, incorrect operation of the circuit can be prevented by erasing a common mode noise which is input with the input signal.Type: GrantFiled: September 2, 2005Date of Patent: October 7, 2008Assignee: Fairchild Korea Semiconductor, Ltd.Inventors: Jong-Tae Hwang, Yun-Kee Lee, Dong-Hwan Kim
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Publication number: 20060220733Abstract: A temperature-independent current source is provided, which includes a current source generating a current that is proportional to the temperature and a current source generating a current that is inversely proportional to the temperature. Values of the circuit elements are selected so that the currents of the current sources add up to a substantially temperature-independent current. Related current sources utilize dual-base Darlington bipolar transistors to generate a temperature-independent current.Type: ApplicationFiled: June 5, 2006Publication date: October 5, 2006Inventors: Jong-Tae Hwang, Dong-Hwan Kim, Yun-Kee Lee
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Patent number: 7057442Abstract: A temperature-independent current source is provided, which includes a current source generating a current that is proportional to the temperature and a current source generating a current that is inversely proportional to the temperature. Values of the circuit elements are selected so that the currents of the current sources add up to a substantially temperature-independent current. Related current sources utilize dual-base Darlington bipolar transistors to generate a temperature-independent current.Type: GrantFiled: April 28, 2004Date of Patent: June 6, 2006Assignee: Fairchild Korea Semiconductor Ltd.Inventors: Jong-Tae Hwang, Dong-Hwan Kim, Yun-Kee Lee
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Patent number: 7042289Abstract: A transconductance control circuit of a rail-to-rail differential input stage is described. The transconductance control circuit senses the gate-source voltages of PMOS and NMOS differential pairs, converts the sensed voltage to a current, compares the current with a reference current, and controls the currents of the PMOS and NMOS differential pairs to control the transconductance of the RTR differential input stage. Also, various types of biasing techniques and matching techniques are used to reduce the variations of the transconductance.Type: GrantFiled: April 2, 2004Date of Patent: May 9, 2006Assignee: Fairchild Korea Semiconductor Ltd.Inventors: Jong-Tae Hwang, Dong-Hwan Kim, Yun-Kee Lee
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Publication number: 20060049859Abstract: A high voltage gate driver circuit according to an embodiment of the present invention controls an operational range of an output signal of a level shifter to be appropriate for an operational range of a reshaper through a VIV converter. Even though the voltage range of the signal which is input from the high voltage gate driver circuit to the level shifter is different from the operational range of the reshaper, the input signal can always be recognized exactly regardless of the VTH voltage of the reshaper by controlling the operational range of the signal through the VIV converter. In addition, incorrect operation of the circuit can be prevented by erasing a common mode noise which is input with the input signal.Type: ApplicationFiled: September 2, 2005Publication date: March 9, 2006Inventors: Jong-Tae Hwang, Yun-Kee Lee, Dong-Hwan Kim
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Publication number: 20040239423Abstract: A transconductance control circuit of a rail-to-rail differential input stage is described. The transconductance control circuit senses the gate-source voltages of PMOS and NMOS differential pairs, converts the sensed voltage to a current, compares the current with a reference current, and controls the currents of the PMOS and NMOS differential pairs to control the transconductance of the RTR differential input stage. Also, various types of biasing techniques and matching techniques are used to reduce the variations of the transconductance.Type: ApplicationFiled: April 2, 2004Publication date: December 2, 2004Inventors: Jong-Tae Hwang, Dong-Hwan Kim, Yun-Kee Lee
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Publication number: 20040232976Abstract: A temperature-independent current source is provided, which includes a current source generating a current that is proportional to the temperature and a current source generating a current that is inversely proportional to the temperature. Values of the circuit elements are selected so that the currents of the current sources add up to a substantially temperature-independent current. Related current sources utilize dual-base Darlington bipolar transistors to generate a temperature-independent current.Type: ApplicationFiled: April 28, 2004Publication date: November 25, 2004Inventors: Jong-Tae Hwang, Dong-Hwan Kim, Yun-Kee Lee
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Patent number: 6181093Abstract: A commutation circuit for a sensorless three-phase BLDC motor enables soft switching in the commutation process without the need for a complex delay circuit and generates signals separate from the back EMF signals of the stator to start the rotation of the motor rotor. The commutation circuit includes a starting circuit adapted to generate a starting clock signal to forcibly start the motor without information associated with the position of the motor rotor and generates first, second and third reference clock signals that are used to drive the motor in constant velocity operation.Type: GrantFiled: August 17, 1999Date of Patent: January 30, 2001Assignee: Fairchail Korea Semiconductor Ltd.Inventors: Shi-Hong Park, Yun-Kee Lee
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Patent number: 5892339Abstract: A three-phase brushless dc motor driving circuit can use only one Hall signal. The magnitude and phase of the Hall signal is used for commutation in order to perform soft switching, and an index marker circuit can determine the starting point of motor rotation. A clock signal is output at extreme points of the Hall signal generated by the Hall sensor. Based on the clock signal, three step voltage signals are generated, each step voltage signal having three voltage levels, signal periods three times that of the Hall signal and 120 and 240 degree phase differences with the other two step voltage signals. The direction of current flow in each stator coil is controlled based on the voltage difference each of the step voltage signals and the Hall signal. Index marker detection is performed by demagnetizing a portion of a magnet in a rotor of the motor and using an additional extreme point resulting in the Hall signal to output an index marker.Type: GrantFiled: September 2, 1997Date of Patent: April 6, 1999Assignee: Samsung Electronics Co., Ltd.Inventors: Shi-Hong Park, Yun-Kee Lee