Abstract: A variable voltage generation circuit includes a first amplification circuit and a second amplification circuit. The first amplification circuit generates a first output voltage based on a reference voltage, a first feedback voltage, a temperature-varied voltage and a temperature-fixed voltage such that the first output voltage is varied in a first voltage range according to a variation of the operational temperature. The first amplification circuit generates the first feedback voltage based on the first output voltage. The second amplification circuit generates a second output voltage based on the first feedback voltage, a second feedback voltage, the temperature-varied voltage and the temperature-fixed voltage such that the second output voltage is varied in a second voltage range wider than the first voltage range according to the variation of the operational temperature. The second amplification circuit generates the second feedback voltage based on the second output voltage.

Abstract: In a method of programming a nonvolatile memory device, a program operation is performed on a selected memory cell coupled to a selected word line in response to a program command, a negative bias voltage is applied to the selected word line, a verification pass voltage is applied to an unselected word line after the negative bias voltage is applied to the selected word line, and a first program verification voltage, which is higher than the negative bias voltage and lower than a ground voltage, is applied to the selected word line.

Abstract: A variable voltage generation circuit includes a first amplification circuit and a second amplification circuit. The first amplification circuit generates a first output voltage based on a reference voltage, a first feedback voltage, a temperature-varied voltage and a temperature-fixed voltage such that the first output voltage is varied in a first voltage range according to a variation of the operational temperature. The first amplification circuit generates the first feedback voltage based on the first output voltage. The second amplification circuit generates a second output voltage based on the first feedback voltage, a second feedback voltage, the temperature-varied voltage and the temperature-fixed voltage such that the second output voltage is varied in a second voltage range wider than the first voltage range according to the variation of the operational temperature. The second amplification circuit generates the second feedback voltage based on the second output voltage.

Abstract: In a method of programming a nonvolatile memory device, a program operation is performed on a selected memory cell coupled to a selected word line in response to a program command, a negative bias voltage is applied to the selected word line, a verification pass voltage is applied to an unselected word line after the negative bias voltage is applied to the selected word line, and a first program verification voltage, which is higher than the negative bias voltage and lower than a ground voltage, is applied to the selected word line.

Abstract: A phase change memory device including a voltage generator that generates an operating voltage by generating at least one modified clock signal, a pulse width of which is maintained constant for at least one clock cycle in response to a pump enable signal being enabled, from at least one reference clock signal, and performing a pump operation on a power supply voltage according to the at least one modified clock signal; and a memory cell array that includes a plurality of phase change memory cells connected between word lines and bit lines. The operating voltage is applied to the memory cell array so as to perform a data access operation.

Abstract: A voltage generator comprises a first booster that generates a first high voltage, and a second booster that generates a second high voltage by boosting an external voltage. The first booster comprises a comparator that controls a boosting operation with reference to the fed back first high voltage and uses the second high voltage as a drive voltage.

Abstract: A phase change memory device including a voltage generator that generates an operating voltage by generating at least one modified clock signal, a pulse width of which is maintained constant for at least one clock cycle in response to a pump enable signal being enabled, from at least one reference clock signal, and performing a pump operation on a power supply voltage according to the at least one modified clock signal; and a memory cell array that includes a plurality of phase change memory cells connected between word lines and bit lines. The operating voltage is applied to the memory cell array so as to perform a data access operation.

Abstract: A voltage generator comprises a first booster that generates a first high voltage, and a second booster that generates a second high voltage by boosting an external voltage. The first booster comprises a comparator that controls a boosting operation with reference to the fed back first high voltage and uses the second high voltage as a drive voltage.

Abstract: A self-calibrating temperature sensor and a method thereof are provided. The self-calibrating temperature sensor may include a reference voltage generator to generate a reference voltage based on temperature, a digital-to-analog converter to convert a first digital signal into an analog sensing voltage, a comparator to compare the reference voltage with the analog sensing voltage, and to generate a comparison result signal, a digital signal generator to generate and update the first digital signal based on the comparison result signal, a first storage circuit to store the first digital signal based on a first temperature, a data output unit to output data corresponding to a second temperature based on the first digital signal and a second digital signal output from the first storage circuit.

Abstract: A self-calibrating temperature sensor and a method thereof are provided. The self-calibrating temperature sensor may include a reference voltage generator to generate a reference voltage based on temperature, a digital-to-analog converter to convert a first digital signal into an analog sensing voltage, a comparator to compare the reference voltage with the analog sensing voltage, and to generate a comparison result signal, a digital signal generator to generate and update the first digital signal based on the comparison result signal, a first storage circuit to store the first digital signal based on a first temperature, a data output unit to output data corresponding to a second temperature based on the first digital signal and a second digital signal output from the first storage circuit.