Abstract: A semiconductor device includes a pulse signal generating unit for generating a plurality of pulse signals each of which has a different pulse width from each other, a signal multiplexing unit for outputting one of the plurality of the pulse signals as an enable signal in response to frequencies of external clock signals, and a duty ratio detecting unit for detecting a duty ratio of the external clock signals in response to the enable signal.

Abstract: A semiconductor memory device with a clock synchronization circuit capable of performing a desired phase/frequency locking operation, without the jitter peaking phenomenon and the pattern jitter of an oscillation control voltage signal using injection locking. The device includes a phase-locked loop that detects a phase/frequency difference between a feedback clock signal and a reference clock signal to generate an oscillation control voltage signal corresponding to the detected phase/frequency difference, and generates the feedback clock signal corresponding to the oscillation control voltage signal. An injection locking oscillation unit sets up a free running frequency in response to the oscillation control voltage signal and generates an internal clock signal which is synchronized with the reference clock signal.

Abstract: A multi-phase clock generation circuit having a low skew imprecision is presented. The circuit includes a phase clock generation block and a phase correction block. The phase clock generation block is configured to generate a plurality of phase clocks having phases different from each other with response to a pair of input clocks. The phase correction block is configured to generate final output interpolated phase clocks in which each has a center phase by adjusted by multiple phase clocks that have adjacent phases.

Abstract: A multi-phase clock signal generating circuit includes a phase correction block configured to receive multi-phase clock signals and produce a plurality of interpolated phase clock signal groups in which the phases of the multi-phase clock signals are differently controlled. The multi-phase clock signals are out of phase with each other. A clock control block is configured to produce output multi-clock signals by selectively outputting one among the interpolated phase clock signal groups using a digital control signal having a plurality of bits which are produced based on phase differences of the multi-phase clock signals.

Abstract: Bias voltage generator circuit and clock synchronizing circuit includes a bias unit configured to control a current in response to a bandwidth control signal, an amplification unit configured to differentially amplify an input signal in response to the current controlled by the bias unit and an output unit configured to receive an output signal of the amplification unit to output the bias voltage.

Abstract: A quadrature phase correction circuit includes an N-bit code counter configured to generate an N-bit code value according to a detected phase difference when a quadrature phase correction is carried out, N-bit code values are stored according to a plurality of detected phase differences. A controller shares the N-bit code counter, controls the generation of the N-bit code values according to the plurality of detected phase differences, and controls the storing of the N-bit code values in an allocated space of the storage by use of a multiplexer configured to provide the plurality of detected phase differences to the N-bit code counter, and a demultiplexer configured to store the N-bit code values in the allocated space of the storage.

Abstract: A multi-phase clock signal generating circuit includes a phase correction block configured to receive multi-phase clock signals and produce a plurality of interpolated phase clock signal groups in which the phases of the multi-phase clock signals are differently controlled. The multi-phase clock signals are out of phase with each other. A clock control block is configured to produce output multi-clock signals by selectively outputting one among the interpolated phase clock signal groups using a digital control signal having a plurality of bits which are produced based on phase differences of the multi-phase clock signals.

Abstract: A counter with overflow prevention capability includes a counting unit configured to count an output code in response to an input signal and an overflow preventing unit configured to control the counting unit to stop counting the output code when a current value of the output code is a maximum value but a previous value thereof is not the maximum value.

Abstract: A multi-phase clock generation circuit having a low skew imprecision is presented. The circuit includes a phase clock generation block and a phase correction block. The phase clock generation block is configured to generate a plurality of phase clocks having phases different from each other with response to a pair of input clocks. The phase correction block is configured to generate final output interpolated phase clocks in which each has a center phase by adjusted by multiple phase clocks that have adjacent phases.

Abstract: A semiconductor device including an edge synchronizer which outputs a synchronized strobe signal generated by synchronizing a transition time point of a strobe signal with clock edges of a main clock or a sub clock, a detector which outputs a phase determination signal indicating a phase difference between the main clock and the sub clock in response to the synchronized strobe signal, and a duty ratio corrector which adjusts a duty ratio of the main clock and the sub clock in response to the phase determination signal.

Abstract: A ring oscillator including a plurality of buffer units, each of which has a cross-coupled structure, for generating clock signals using a bias voltage having a predetermined voltage level applied thereto, wherein the clock signals have a swing width corresponding to the bias voltage.

Abstract: A semiconductor device including an edge synchronizer which outputs a synchronized strobe signal generated by synchronizing a transition time point of a strobe signal with clock edges of a main clock or a sub clock, a detector which outputs a phase determination signal indicating a phase difference between the main clock and the sub clock in response to the synchronized strobe signal, and a duty ratio corrector which adjusts a duty ratio of the main clock and the sub clock in response to the phase determination signal.

Abstract: Semiconductor memory device with duty correction circuit includes a clock edge detector configured to generate first and second detection pulses in response to a transition timing of a common clock signal in an initial measurement operation; a duty detector configured to compare the first and second detection pulses to output comparison result signals; and a code counter configured to control the duty detector based on the comparison signals outputted from the duty detector in the initial measurement operation.

Abstract: A quadrature phase correction circuit includes an N-bit code counter configured to generate an N-bit code value according to a detected phase difference when a quadrature phase correction is carried out; a storage configured to store N-bit code values according to a plurality of detected phase differences; and a controller configured to share the N-bit code counter, control the generation of the N-bit code values according to the plurality of detected phase differences, and control the storing of the N-bit code values in an allocated space of the storage.

Abstract: A semiconductor memory device includes an edge detector configured to receive two pairs of complementary clocks to detect edges of the clocks, a comparator configured to compare output signals of the edge detector to detect whether clocks of the same pair have a phase difference of 180 degrees and detect whether clocks of different pairs have a phase difference of 90 degrees, a control signal generator configured to generate a control signal for controlling phases of the clocks according to an output signal of the comparator, and a phase corrector configured to correct phases of the clocks in response to the control signal.

Abstract: A low pass filter includes a driver unit configured to output a voltage proportional to an input pulse width, a charge/discharge unit configured to charge the output voltage of the driver unit, a comparator unit configured to compare an output voltage of the charge/discharge unit with a reference value to output a square wave signal, and a switching unit configured to switch the charge/discharge unit to an operation state, based on a bandwidth expansion signal.

Abstract: Bias voltage generator circuit and clock synchronizing circuit includes a bias unit configured to control a current in response to a bandwidth control signal, an amplification unit configured to differentially amplify an input signal in response to the current controlled by the bias unit and an output unit configured to receive an output signal of the amplification unit to output the bias voltage.

Abstract: Apparatus for detecting duty ratio of signals in semiconductor device circuit includes a circuit for detecting a duty ratio of signals in a semiconductor device includes a comparing unit which compares a duty cycle of first and second input clock signals input differentially and generates a first output signal and a second output signal, a latching unit which stores the first and second output signals and generates a detected signal corresponding to the first and second output signals, and an adjusting unit which receives the first and the second output signals, and transmits the first and the second output signals to the latching unit based on a voltage level difference of the first and second output signals.

Abstract: A semiconductor device includes a pulse signal generating unit for generating a plurality of pulse signals each of which has a different pulse width from each other, a signal multiplexing unit for outputting one of the plurality of the pulse signals as an enable signal in response to an operating frequency of the semiconductor device, and a duty ratio detecting unit for detecting a duty ratio of external clock signals in response to the enable signal.

Abstract: A semiconductor memory device can optimize the layout area and current consumption based on multi-phase clock signals which are generated by dividing a source clock signal using a reset signal without a delay locked loop and a phase locked loop in order to have various phase information of low frequencies and different activation timings with a constant phase difference.