Abstract: Provided herein may be a test circuit of an electronic device, the electronic device including the test circuit, and an operating method thereof. The electronic device may include analog circuits, a control circuit configured to connect, to an output terminal, each of a plurality of nodes respectively included in the analog circuits to an output terminal, a control signal generator configured to generate a control signal for controlling the control circuit based on an input signal received from an external device, and a switching circuit disposed on an electrical path for connecting the plurality of nodes and the control circuit to each other and configured to be electrically open during a preset time amount from a time point at which a voltage from an external power source starts to be applied to the control circuit.

Abstract: A semiconductor device may include a main circuit component and a spare circuit component including a plurality of spare elements and selected to change a function of the main circuit component, wherein each of the plurality of spare elements is configured to block a source voltage supply.

Abstract: A semiconductor device may include a main circuit component and a spare circuit component including a plurality of spare elements and selected to change a function of the main circuit component, wherein each of the plurality of spare elements is configured to block a source voltage supply.

Abstract: A voltage-controlled oscillator includes: a bias voltage generator operating to generate first and second bias voltages in response to a control signal; a voltage-controlled oscillation circuit connected to a control node and configured to generate oscillation signals in response to an input voltage; a selection signal generator operating to generate a selection signal in response each to the oscillation signals; and a selection circuit operating to select one of the first and second bias voltages in response to the selection signal and outputting the selected bias voltage to the control node.

Abstract: A voltage-controlled oscillator includes: a bias voltage generator operating to generate first and second bias voltages in response to a control signal; a voltage-controlled oscillation circuit connected to a control node and configured to generate oscillation signals in response to an input voltage; a selection signal generator operating to generate a selection signal in response each to the oscillation signals; and a selection circuit operating to select one of the first and second bias voltages in response to the selection signal and outputting the selected bias voltage to the control node.

Abstract: A low-power multi-level pulse amplitude modulation (PAM) driver, and a semiconductor device having the same, in which the multi (M)-level PAM driver includes a load unit, first and second current sources, a pair of first input transistors, a pair of second input transistors, and a current source controller, where M is an integer greater than 3. The load unit is electrically connected to an output terminal, and the first and second current sources respectively supply a first amount of current and a second amount of current to the load unit. The pair of first input transistors electrically connects the first current source and the load unit in response to a first bit signal, and the pair of the second input transistors electrically connects the second current source and the load unit in response to a second bit signal. The current source controller activates or deactivates one of the first and second current sources in response to the first and second bit signals.

Abstract: A low-power multi-level pulse amplitude modulation (PAM) driver, and a semiconductor device having the same, in which the multi (M)-level PAM driver includes a load unit, first and second current sources, a pair of first input transistors, a pair of second input transistors, and a current source controller, where M is an integer greater than 3. The load unit is electrically connected to an output terminal, and the first and second current sources respectively supply a first amount of current and a second amount of current to the load unit. The pair of first input transistors electrically connects the first current source and the load unit in response to a first bit signal, and the pair of the second input transistors electrically connects the second current source and the load unit in response to a second bit signal. The current source controller activates or deactivates one of the first and second current sources in response to the first and second bit signals.

Abstract: The present invention relates to a ROM division method for reducing the size of a ROM in a direct digital frequency synthesizer (DDFS), which is used to synthesize a frequency in a communication system requiring fast frequency conversion. A ROM consuming most energy in the system, a modified Nicholas architecture is brought forth to reduce the size of ROM. In this modified Nicholas architecture, a ROM is divided into coarse ROM and fine ROM to convert phase to sine value. The present invention divides the coarse ROM and the fine ROM into quantized ROM and error ROM respectively. Then, value stored in each ROM is segmented in certain intervals and the minimum quantized value in each of the section is stored in the quantized ROM, while the difference between the original ROM value and the quantized ROM value is stored in the error ROM. This way, the size of a ROM can be reduced. Phase value inputted in a DDFS, a sine value is calculated by adding the four ROM values, i.e.

Abstract: The present invention relates to a ROM division method for reducing the size of a ROM in a direct digital frequency synthesizer (DDFS), which is used to synthesize a frequency in a communication system requiring fast frequency conversion. A ROM consuming most energy in the system, a modified Nicholas architecture is brought forth to reduce the size of ROM. In this modified Nicholas architecture, a ROM is divided into coarse ROM and fine ROM to convert phase to sine value. The present invention divides the coarse ROM and the fine ROM into quantized ROM and error ROM respectively. Then, value stored in each ROM is segmented in certain intervals and the minimum quantized value in each of the section is stored in the quantized ROM, while the difference between the original ROM value and the quantized ROM value is stored in the error ROM. This way, the size of a ROM can be reduced. Phase value inputted in a DDFS, a sine value is calculated by adding the four ROM values, i.e.