Abstract: Disclosed is an energy storage system provided with a wired and wireless energy transfer function. The energy storage system includes: an energy input unit to which energy generated from a plurality of energy sources is input; an energy input control unit for selecting one energy source from among the plurality of energy sources, and transferring energy of the selected energy source through operation in a wired operation mode or a wireless operation mode; a wireless energy transmitting/receiving unit for wirelessly transmitting/receiving the energy of the selected energy source during the operation in the wireless operation mode of the energy input control unit; an energy storage/control unit for storing the energy of the selected energy source; an energy output unit for consuming the energy stored in the energy storage/control unit; and an energy output control unit for distributing the energy stored in the energy storage/control unit to the energy output unit.

Abstract: Disclosed is a DC-DC converter, including: a switch unit configured to generate output voltage for driving a load; an output voltage monitoring unit including a reference voltage generator generating reference voltage and a reference voltage capacitor maintaining the reference voltage when power of the reference voltage generator is interrupted and configured to generate a signal for setting the output voltage as the reference voltage; a switch controlling unit configured to control the switch unit by being operated in a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode by using the signal of the output voltage monitoring unit; and a mode determining and power interrupting unit configured to set an operating mode of the switch controlling unit as the PWM mode or the PFM mode according to a magnitude of the load and interrupt power of the reference voltage generator when operated in the PFM mode.

Abstract: Disclosed is a DC-DC converter including: a switch unit controlling a flow of a current based on a buck-boost topology; a short circuit unit short circuited or opened according to an external setting to change a topology of the switch unit; an inductor storing a current induced by the switch unit; a topology selecting unit selecting a topology in response to an external input signal and generating a signal corresponding to the selected topology; a pulse width modulating unit generating a signal for determining an operation time of the switch unit; a reverse flow detecting unit detecting a reverse flow of a current flowing through the switch unit to generate a signal; and a switch control unit controlling the switch unit in response to signals of the topology selecting unit, the pulse width modulating unit and the reverse flow detecting unit.

Abstract: A reference voltage supply circuit is provided. The reference voltage supply circuit includes a first amplifier for amplifying a first input voltage and a fed back first reference voltage, a second amplifier for amplifying a second input voltage and a fed back second reference voltage, a reference voltage generator for generating the first reference voltage and the second reference voltage according to output signals of the first and second amplifiers and feeding the first and second reference voltages back to the first and second amplifiers, and a glitch remover turned on/off according to an input pulse signal to conduct or cut off current flowing between a power supply terminal and the ground.

Abstract: Disclosed is an energy storage system provided with a wired and wireless energy transfer function. The energy storage system includes: an energy input unit to which energy generated from a plurality of energy sources is input; an energy input control unit for selecting one energy source from among the plurality of energy sources, and transferring energy of the selected energy source through operation in a wired operation mode or a wireless operation mode; a wireless energy transmitting/receiving unit for wirelessly transmitting/receiving the energy of the selected energy source during the operation in the wireless operation mode of the energy input control unit; an energy storage/control unit for storing the energy of the selected energy source; an energy output unit for consuming the energy stored in the energy storage/control unit; and an energy output control unit for distributing the energy stored in the energy storage/control unit to the energy output unit.

Abstract: Provided are an anode in which lithium metal powder and carbon powder are physically mixed with each other to form a composite and the composite is applied as an anode layer, and a lithium metal secondary battery including the anode. The anode of the present invention may suppress the formation of lithium dendrites and the change in volume of cells generated in a rechargeable battery which uses a lithium metal anode and significantly improve the cycle life-span of a lithium metal secondary battery by physically mixing lithium metal particles and carbon particles having an equivalent average particle diameter with each other to be applied as an anode layer.

Abstract: Disclosed is a DC-DC converter, including: a switch unit configured to generate output voltage for driving a load; an output voltage monitoring unit including a reference voltage generator generating reference voltage and a reference voltage capacitor maintaining the reference voltage when power of the reference voltage generator is interrupted and configured to generate a signal for setting the output voltage as the reference voltage; a switch controlling unit configured to control the switch unit by being operated in a pulse width modulation (PWM) mode or a pulse frequency modulation (PFM) mode by using the signal of the output voltage monitoring unit; and a mode determining and power interrupting unit configured to set an operating mode of the switch controlling unit as the PWM mode or the PFM mode according to a magnitude of the load and interrupt power of the reference voltage generator when operated in the PFM mode.

Abstract: Provided is an apparatus for calculating an absolute difference capable of efficiently performing an absolute difference using an adder. The apparatus for calculating an absolute difference includes a comparator comparing values of two integers, first and second selectors each selecting and outputting one of the two integers according to the comparison results of the comparator, an inverter complementing the result value selected by the second selector; and an adder adding up the result value selected by the first selector, the value complemented by the inverter, and 1.

Abstract: Disclosed is a DC-DC converter including: a switch unit controlling a flow of a current based on a buck-boost topology; a short circuit unit short circuited or opened according to an external setting to change a topology of the switch unit; an inductor storing a current induced by the switch unit; a topology selecting unit selecting a topology in response to an external input signal and generating a signal corresponding to the selected topology; a pulse width modulating unit generating a signal for determining an operation time of the switch unit; a reverse flow detecting unit detecting a reverse flow of a current flowing through the switch unit to generate a signal; and a switch control unit controlling the switch unit in response to signals of the topology selecting unit, the pulse width modulating unit and the reverse flow detecting unit.

Abstract: Provided is a read-out circuit that is connected to a microphone and configured to linearly amplify a current signal generated by the microphone and output the amplified current signal. The read-out circuit includes an amplification unit and a feedback resistor. The amplification unit has an amplification gain between 0 and 1. The feedback resistor is connected between input and output terminals of the amplification unit. As the amplification gain of the amplification unit becomes closer to 1, an input impedance becomes higher. A preamp of the read-out circuit can have a high input impedance due to the amplification gain, and the read-out circuit can be manufactured using a CMOS process.

Abstract: A phase-locked loop (PLL) circuit including a voltage-controlled oscillator (VCO) with a variable gain is provided. A phase frequency detector (PFD) detects a phase difference between a reference signal and a PLL feedback signal. A charge pump and a loop filter sequentially process an output signal of the PFD. A VCO has different gains according to a mode transition. A control voltage applied to the VCO is selected from an output signal of the loop filter and an additional control signal according to the mode transition.

Abstract: Provided are a switching circuit and a small-size high-efficiency direct current-to-direct current (DC-DC) converter for portable devices including the same. Using dynamic threshold-complementary metal oxide semiconductor (DT-CMOS) transistors having dynamic threshold voltages as a switching device, the switching circuit maintains a low threshold voltage in a normal mode to improve current drivability while reducing conduction loss, and maintains a high threshold voltage in a standby mode to minimize power consumption. When the switching circuit is employed in a DC-DC converter, power conversion efficiency can be improved by reducing conduction loss in the normal mode, and power consumption can be minimized in the standby mode. Consequently, the DC-DC converter can maximize a use time of a battery of a portable device and can be useful in power supplies of portable devices that are gradually being miniaturized.

Abstract: Provided is a transformer-based oscillator which is suited to oscillate frequencies in multiple bands. An oscillator includes a transformer resonance unit and a plurality of complementary transistors. The transformer resonance unit includes a primary coil and a secondary coil corresponding to the primary coil. The plurality of complementary transistors have gates and drains between which both ends of the transformer resonance unit are respectively connected. Thus, the oscillator may operate in a differential mode or common mode according to the phase of the transformer resonance unit. Also, a complementary transistor constituting a multiband oscillation loop may be independently connected to both ends of the transformer resonance unit, and an oscillation loop of at least one band may be selected out of a multiband oscillation loop using a switch unit. Thus, the oscillator may be suited to oscillate resonance frequencies in multiple bands.

Abstract: Provided is an offset-voltage calibration circuit. The circuit includes a comparator configured to receive at least two comparison voltages and output a result of a comparison between the comparison voltages, an up/down counter (UDC) configured to output an up-counting or down-counting output signal in response to an output signal of the comparator, and a current digital-to-analog converter (DAC) configured to control the amount of current supplied from a node to which the comparison voltage is applied, in response to the output signal of the UDC and control the magnitude of the comparison voltage.

Abstract: Provided are a memory system and an integrated management method for a plurality of direct memory access (DMA) channels. The memory system includes a memory controller exchanging data with a memory and having a plurality of channels physically separated from each other, and a DMA controller having a plurality of DMA channels physically separated from each other and in contact with the plurality of channels of the memory controller, and exchanging data with the memory via the plurality of DMA channels and the memory controller.

Abstract: An LC voltage-controlled oscillator (VCO) is provided. The LC VCO includes an LC resonant circuit including at least one inductor whose both terminals are connected to output nodes and at least one capacitor connected in parallel with the inductor, and an amplifier circuit including at least one pair of switching transistors. Here, drains of the pair of switching transistors are connected to the output nodes respectively, and gates of the switching transistors are connected with the drains through a variable capacitance block exhibiting different characteristics according to an input signal.

Abstract: Provided are a memory system and an integrated management method for a plurality of direct memory access (DMA) channels. The memory system includes a memory controller exchanging data with a memory and having a plurality of channels physically separated from each other, and a DMA controller having a plurality of DMA channels physically separated from each other and in contact with the plurality of channels of the memory controller, and exchanging data with the memory via the plurality of DMA channels and the memory controller.

Abstract: Provided are an active resistance-capacitance (RC) integrator and a continuous-time sigma-delta modulator, which have a gain control function. The active RC integrator includes an amplifier, a first base resistor connected between a first input node and a positive input port of the amplifier, a second base resistor connected between a second input node and a negative input port of the amplifier, a first resistor unit connected between the second input node and the positive input port of the amplifier, and a second resistor unit connected between the first input node and the negative input port of the amplifier. A resistor network including resistors and switches is configured to vary an input resistance, so that an active RC integrator may have a gain control function.

Abstract: Provided are a coefficient multiplier and digital delta-sigma modulator using the same. The coefficient multiplier has the average of output signals of respective dependent multipliers as an effective coefficient using a coefficient averaging technique without employing an adder that has a complex structure and occupies a large chip area. Accordingly, the coefficient multiplier has a simple hardware constitution and small chip area in comparison with a canonical signed digit (CSD) coefficient multiplier, and the digital delta-sigma modulator employing the coefficient multiplier has a simple structure and small size.

Abstract: Provided is a pipeline analog-to-digital converter (ADC) without a front-end sample-and-hold amplifier (SHA). To minimize a sampling error occurring between a flash ADC and a multiplying digital-to-analog converter (MDAC) of a first sub-ranging ADC due to removal of a front-end SHA, a delay time of a preamplifier included in the flash ADC is calculated, and the flash ADC samples an analog input signal later by the delay time than the MDAC. Accordingly, the pipeline ADC can minimize a sampling error without using a front-end SHA, and its chip area and power consumption can be reduced.