摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Provided is a gain amplifier having a switched-capacitor structure capable of minimizing settling time, in which an input capacitor is connected to an input terminal during a first clock sampling an input signal, and thus an output terminal of the amplifier is reset in advance to an estimated output voltage value rather than 0 by the input capacitor. Accordingly, the slight move of the output terminal of the amplifier is sufficient to settle to a desired value in an amplification mode, so that slewing time can be reduced, and as a result, overall settling time and power consumption can be minimized.
摘要:
Provided is a multi-bit pipeline analog-to-digital converter (ADC) having a shared amplifier structure. The multi-bit pipeline ADC includes: a sample-and-hold amplifier (SHA) for sampling and holding an input analog voltage and removing a sampling error of the input voltage; N-bit flash ADCs of first to K-th stages receiving analog signals, converting them into digital signals and outputting the digital signals; N-bit multiplying digital-to-analog converters (MDACs) of first to K-th stages converting differences between the digital signals output from the N-bit flash ADCs and output signals of preceding stages back into analog signals and outputting the analog signals; and a three-stage amplifier connected with an output of the N-bit MDAC of the first stage at a first clock and an output of the SHA at a second clock, wherein N is an integer greater than or equal to 1 and K is an integer greater than or equal to 2.In the multi-bit pipeline ADC, an amplifier can be shared between an SHA consuming much power and an MDAC of a first stage, so that power consumption and chip size can be reduced.
摘要:
Provided are a pipeline Analog-to-Digital Converter (ADC) without a front-end Sample-and-Hold Amplifier (SHA) and a method of controlling the same. The method includes the steps of: simultaneously sampling, at an ADC and a residual signal generator included in a first stage, an analog input signal and respectively generating a first sampling value and a second sampling value; holding, at the residual signal generator, the second sampling value, and simultaneously amplifying and converting, at the ADC, the first sampling value into a corresponding digital code; and generating, at the residual signal generator, a residual signal using the digital code. The pipeline ADC and method of controlling the same minimize sampling mismatch caused by removing a front-end SHA, thereby ensuring stable performance without a front-end SHA. Since a front-end SHA is not used, it is possible to reduce chip size and power consumption, and improve the performance of the ADC.
摘要:
Provided is a gain amplifier having a switched-capacitor structure capable of minimizing settling time, in which an input capacitor is connected to an input terminal during a first clock sampling an input signal, and thus an output terminal of the amplifier is reset in advance to an estimated output voltage value rather than 0 by the input capacitor. Accordingly, the slight move of the output terminal of the amplifier is sufficient to settle to a desired value in an amplification mode, so that slewing time can be reduced, and as a result, overall settling time and power consumption can be minimized.
摘要:
A multi-bit pipeline analog-to-digital converter (ADC) having a shared amplifier structure includes: a sample-and-hold amplifier (SHA) for sampling and holding an input analog voltage and removing a sampling error of the input voltage; N-bit flash ADCs of first to K-th stages receiving analog signals, converting them into digital signals and outputting the digital signals; N-bit multiplying digital-to-analog converters (MDACs) of first to K-th stages converting differences between the digital signals output from the N-bit flash ADCs and output signals of preceding stages back into analog signals and outputting the analog signals; and a three-stage amplifier connected to an output of the N-bit MDAC of the first stage at a first clock and an output of the SHA at a second clock, wherein intergers N>= and K>=2. An amplifier can be shared between an SHA and an MDAC of a first stage, thereby reducing power consumption and chip size.In the multi-bit pipeline ADC, an amplifier can be shared between an SHA consuming much power and an MDAC of a first stage, so that power consumption and chip size can be reduced.
摘要:
A wide-band multimode frequency synthesizer using a Phase Locked Loop (PLL) is provided. The multiband frequency synthesizer includes a multimode prescaler, a phase detector/a charge pump, a swallow type frequency divider, and a switching bank LC tuning voltage-controlled oscillator having wide-band and low phase noise characteristics. The multimode prescaler operates in five modes and divides a signal up to 12 GHz. The wide-band frequency synthesizer can be used in various fields such as WLAN/HYPERLAN/DSRC/UWB systems that operate in the frequency range from 2 GHz to 9 GHz. The wide-band multimode frequency synthesizer includes a frequency/phase detector for comparing a frequency and phase of a reference high-frequency signal with a frequency and phase of a feedback high-frequency signal; a charge pump for producing an output current corresponding to the result of the comparison performed by the frequency/phase detector; a loop filter for producing an output voltage corresponding to an accumulated value of the output current of the charge pump; a voltage-controlled oscillator for generating an oscillation signal having a frequency corresponding to the output voltage of the loop filter; and a variable frequency divider for dividing an output signal of the voltage-controlled oscillator by a designated integer value, and outputting the result as a feedback signal, wherein at lease two of an amount of unit pumping charges of the charge pump, an RLC value of the loop filter, an RLC value of the voltage-controlled oscillator, and a divisor value of the variable frequency divider are controlled according to a band.