Electronics and Telecommunications Research Institute

Yong-Wook Lee

Hyun-Tak Kim

Sun-Jin Yun

Bong-Jun Kim

Byung-Gyu Chae

Kwang-Yong Kang

Sung-Youl Choi

Sang-Kuk Choi

Gyung-Ock Kim

JungWook Lim

Jung-Wook Lim

Gyungock Kim

Bongjun Kim

Sungyoul Choi

Sung-Lyul Maeng

Doo-Hyeb Youn

Jae-Yeob Shim

Provided are a method and circuit for controlling heat generation of a power transistor, in which the power transistor can be protected by preventing heat generation of the power transistor by using a metal-insulator transition (MIT) device that can function as a fuse and can be semi-permanently used. The circuit for controlling heat generation of a transistor includes a metal-insulator transition (MIT) device in which abrupt MIT occurs at a predetermined critical temperature; and a power transistor connected to a driving device and controlling power-supply to the driving device, wherein the MIT device is attached to a surface or heating portion of the transistor and is connected to a base terminal or gate terminal of the transistor or a surrounding circuit from a circuit point of view, and wherein when a temperature of the transistor increases to a temperature equal to or greater than the predetermined critical temperature, the MIT device reduces or shuts off a current of the transistor so as to prevent heat generation of the transistor.

Method and circuit for controlling radiant heat of transistor using metal-insulator transition device

Provided are a 3-terminal MIT switch which can easily control a discontinuous MIT jump and does not need a conventional gate insulating layer, a switching system including the 3-terminal MIT switch, and a method of controlling an MIT of the 3-terminal MIT switch. The 3-terminal MIT switch includes a 2-terminal MIT device, which generates discontinuous MIT in a transition voltage, an inlet electrode and an outlet electrode, which are respectively connected to each terminal of the 2-terminal MIT device, and a control electrode, which is connected to the inlet electrode and includes an external terminal separated from an external terminal of the inlet electrode, wherein an MIT of the 2-terminal MIT device is controlled according to a voltage or a current applied to the control electrode. The switching system includes the 3-terminal MIT switch, a voltage source connected to the inlet electrode, and a control source connected to the control electrode.

Three-terminal metal-insulator transition switch, switching system including the same, and method of controlling metal-insulator transition of the same

Provided are a germanium (Ge) based metal-insulator transition (MIT) thin film which is formed of a Ge single-element material instead of a compound material of two or more elements and by which material growth may be easily performed and a problem of a second phase characteristic in accordance with a structural defect and an included impurity may be solved, an MIT device including the MIT thin film, and a method of fabricating the MIT device. The MIT device includes a substrate; a germanium (Ge) based MIT thin film which is formed of a Ge single-element material on the substrate and in which a discontinuous MIT occurs at a predetermined transition voltage; and at least two thin film electrodes contacting the Ge based MIT thin film, wherein the discontinuous MIT occurs in the Ge based MIT thin film due to a voltage or a current which is applied through the thin film electrodes.

Germanium based metal-insulator transition thin film, metal-insulator transition device including the metal-insulator transition thin film, and method of fabricating the metal-insulator transition device

Provided are an abrupt MIT device with variable MIT temperature or voltage, an MIT sensor using the abrupt MIT device, and an alarm apparatus and a secondary battery anti-explosion circuit including the MIT sensor. The MIT device includes an abrupt MIT layer undergoing an abrupt MIT at a transition temperature or a transition voltage and at least two electrode layers contacting the abrupt MIT layer. The transition temperature or the transition voltage varies with at least one of factors including a voltage applied to the electrode layers, a temperature, an electromagnetic wave, a pressure, and a gas concentration that affect the abrupt MIT layer. The MIT sensor is a temperature sensor, an infrared sensor, an image sensor, a pressure sensor, a gas-concentration sensor, or a switch. The alarm apparatus includes the MIT sensor and an alarm-signaling unit connected in series with the MIT sensor. The secondary battery anti-explosion circuit includes a secondary battery, the MIT sensor attached to the secondary battery to sense the temperature of the secondary battery and thus to prevent the possible explosion of the secondary battery, and a protection circuit body powered by the secondary battery.

Programmable MIT sensor using the abrupt MIT device, and alarm apparatus and secondary battery anti-explosion circuit including the MIT sensor

Provided are a circuit for continuously measuring a discontinuous metal-insulator transition (MIT) of an MIT element and an MIT sensor using the circuit. The circuit comprises a to-be-measured object unit including the MIT element having a discontinuous MIT occurring at the transition voltage thereof, a power supply unit applying a predetermined pulse current or voltage signal to the to-be-measured object unit, a measurement unit measuring the discontinuous MIT of the MIT element, and a microprocessor controlling the power supply unit and the measurement unit. The discontinuous MIT measurement circuit continuously measures the discontinuous MIT of the MIT element, and thus it can be used as a sensor for sensing a variation in an external factor.

Circuit for continuously measuring discontinuous metal insulator transition of MIT element and MIT sensor using the same

Provided are an oscillatory circuit based on a metal-insulator transition (MIT) device that can generate a simple and very high oscillating frequency using the MIT device, and a method of driving the oscillatory circuit. The oscillatory circuit includes the MIT device that comprises an MIT thin film and an electrode thin film connected to the MIT thin film and in which an abrupt MIT is generated due to an MIT generating voltage, a resistor that is serially connected to the MIT device, an electric al power source limiting the maximum amount of an applied current and applying a direct current constant voltage to the MIT device, and a light source irradiating electromagnetic waves on the MIT device, wherein the oscillating properties are generated by irradiating the electromagnetic waves using the light source.

Oscillation circuit based on metal-insulator transition device and method of driving the oscillation circuit

Provided are an MIT device-based oscillation circuit including a power source, an MIT device and a variable resistor, in which a generation of an oscillation and an oscillation frequency are determined according to a voltage applied from the power source and a resistance of the variable resistor, and a method of adjusting the oscillation frequency of the oscillation circuit. The MIT device includes an MIT thin film and an electrode thin film connected to the MIT thin film, and generates a discontinuous MIT at an MIT generation voltage, the variable resistor is connected in series to the MIT device, and the power source applies a voltage or an electric current to the MIT device. The generation of an oscillation and an oscillation frequency are determined according to the voltage applied from the power source and the resistance of the variable resistor.

Oscillation circuit including MIT device and method of adjusting oscillation frequency of the oscillation circuit

Provided is a lithium secondary battery including a discharge unit capable of delaying or preventing a battery explosion. The lithium secondary battery includes a discharge unit disposed parallel to a battery body. The discharge unit includes a first electrode connected to a positive electrode of the battery body, a second electrode connected to a negative electrode of the battery body, and a discharge material film, disposed between the first electrode and the second electrode, inducing a abrupt discharge above a predetermined temperature. The discharge material film, e.g., a abrupt metal-insulator transition (MIT) material film can induce a abrupt discharge, thereby preventing or delaying a battery explosion.

Lithium secondary battery including discharge unit

An abrupt MIT (metal-insulator transition) device with parallel MIT material layers is provided. The abrupt MIT device includes a first electrode disposed on a certain region of a substrate, a second electrode disposed so as to be spaced a predetermined distance apart from the first electrode, and at least one MIT material layer electrically connecting the first electrode with the second electrode and having a width that allows the entire region of the MIT material layer to be transformed into a metal layer due to an MIT. Due to this configuration, deterioration of the MIT material layer, which is typically caused by current flowing through the MIT material layer, is less likely to occur.

Abrupt metal-insulator transition device with parallel MIT material layers

Provided are a temperature sensor using a metal-insulator transition (MIT) device subject to abrupt MIT at a specific temperature and an alarm including the temperature sensor. The abrupt MIT device includes an abrupt MIT thin film and at least two electrode thin films that contacts the abrupt MIT thin film. The abrupt MIT device generates abrupt metal-insulator transition at a specific transition temperature. The alarm includes a temperature sensor comprising an abrupt MIT device, and an alarm signaling device serially connected to the temperature sensor. Accordingly, the alarm can be manufactured to have a simple circuit and be of a small size by including the temperature sensor using an abrupt MIT device.

Temperature sensor using abrupt metal-insulator transition (MIT) and alarm comprising the temperature sensor

Provided are a low-voltage noise preventing circuit using an abrupt metal-insulator transition (MIT) device which can effectively remove a noise signal with a voltage less than a rated signal voltage. The abrupt MIT device is serially connected to the electrical and/or electronic system to be protected from the noise signal, and is subject to abrupt MIT at a predetermined voltage. Accordingly, low-voltage noise can be effectively removed.

Low-voltage noise preventing circuit using abrupt metal-insulator transition device

Provided are a memory device that undergoes no structural phase change, maintains a uniform thin film, and can perform a high-speed switching operation, and a method of operating the same. The memory device includes a substrate, an abrupt MIT material layer, and a plurality of electrodes. The abrupt MIT material layer is disposed on the substrate and undergoes an abrupt metal-insulator transition by an energy change between electrons. The plurality of electrodes are brought into contact with the abrupt MIT material layer and are melted by heat to form a conductive path on the abrupt MIT material layer.

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Daejeon, South Korea

Yong-Wook Lee