Samsung Electronics Co., Ltd.

Gyung-Su Byun

Kyu-Hyoun Kim

Jung-hwan Choi

Woo-seop Kim

Il-Man Bae

Nak-won Heo

A semiconductor driver circuit includes impedance units for generating impedances at data pads, independently of each-other. Thus, signal swing widths of data signals generated at the data pads may be easily adjusted to be substantially equal for high operating speed. The semiconductor driver circuit also includes switching units for uncoupling at least one of the impedance units from at least one of the data pads for enhanced testing of the data pads.

Semiconductor driver circuit with signal swing balance and enhanced testing

A duty cycle correction (DCC) circuit receives first and second clock signals and outputs a duty cycle adjusted clock signal, and a control circuit detects a process variation and controls respective slew rates of the first and second clock signals based on the detected process variation. The DCC circuit may include a first inverter having an input that receives the first clock signal, a second inverter having an input that receives the second clock signal, a third inverter having an input commonly connected to outputs of the first and second inverters, a first variable capacitor connected between the input of the first inverter and a ground voltage, and a second variable capacitor connected between the input of the first inverter and the ground voltage. In this case, the respective capacitance values of the first and second variable capacitors are set by the control circuit.

Semiconductor device including duty cycle correction circuit

An embodiment of a differential output driver includes a driver to generate an inverted output signal in response to an input signal and a first control signal, and to further generate an output signal in response to an inverted input signal and a second control signal. The differential output driver also includes a controller to generate the first control signal and the second control signal in response to detecting a voltage difference between a first detected voltage difference between a reference voltage and the output signal, and a second detected voltage difference between the reference voltage and the inverted output signal.

Differential output driver and semiconductor device having the same

Disclosed herein is a layout structure of a signal driver. The layout structure of the signal driver of the present invention includes a first signal response unit, a second signal response unit, and a current source unit. The first signal response unit responds to a first input signal, and the second signal response unit responds to a second input signal. The current source unit has a plurality of bias unit pairs for restricting currents provided to the first and second signal response units to respective source currents thereof. The bias unit pairs each include at least two bias units, which are separately arranged on opposite sides of a predetermined imaginary centerline. According to the layout structure of the signal driver of the present invention, there is a benefit in that current mismatch occurring between the first and second current response units is reduced, thus consequently improving the operating characteristics of the signal driver.

Layout structure of signal driver

A delay locked loop capable of performing a reliable locking operation is provided that includes a phase controller, which controls a phase of a reference clock signal in response to first and second phase control signals, and a phase detector, which compares the phase of the reference clock signal to a phase of a feedback clock signal and outputs the first and second phase control signals to match the phase of the reference clock signal and the phase of the feedback clock signal, where the phase detector keeps the length of a detecting window constant in response to a current signal despite changes in external voltage, temperature, and the manufacturing process.

Delay locked loop capable of performing reliable locking operation

A semiconductor device having a delay-locked loop includes: a variable delayer that delays a clock signal for a predetermined period of time to generate an internal clock signal; a normal pass that outputs data read from a memory cell outside the semiconductor device in response to the internal clock signal; a replica pass that has a substantial identical time delay to the normal pass and delays the internal clock signal to generate an output signal; and a phase detector that compares a phase of the clock signal with a phase of a predetermined feedback clock signal to control a time delay in the variable delayer. Here, the internal clock signal is output, instead of the output signal from the replica pass, as the predetermined feedback clock signal in a predetermined test mode.

Semiconductor device having delay-locked loop and test method thereof

In a delay locked loop (DLL) of a semiconductor memory device capable of compensating for delay of an internal clock signal by variation of driving strength of an output driver, a replica output driver exhibits the same delay amount as the delay amount as an output driver whose driving strength varies. A phase detector detects a phase difference between an internal clock signal which is delayed by the replica output driver, and an external clock signal. A control circuit generates a control signal in response to the output signal of the phase detector. A variable delay circuit, in response to the control signal, delays the external clock signal and generates the internal clock signal in synchronization with the external clock signal. Since the DLL has a replica output driver which can accurately track the delay of an internal clock signal by variation of the driving strength of an output driver in the feedback loop, output data can be accurately synchronized with an external clock signal.

Delay locked loop capable of compensating for delay of internal clock signal by variation of driving strength of output driver in semiconductor memory device

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Seoul, South Korea

Gyung-Su Byun