Abstract: An on die thermal sensor (ODTS) in a memory device includes: a band gap unit for detecting a temperature of the memory device to output a first voltage corresponding to the temperature; and an analog-to-digital converting unit for outputting a digital code having temperature information based on the first voltage, the digital code having varied resolution according to temperature ranges.

Abstract: A semiconductor memory device includes: a temperature information output unit for measuring an internal temperature of the semiconductor memory device, and generating a plurality of flag signals, each voltage level of which varies according to the measured internal temperature; a self-refresh oscillation unit for providing a self-refresh period corresponding to the measured internal temperature in response to the plurality of flag signals; and a temperature information control unit for determining a measuring period of the temperature information output unit in response to a temperature sensing enable signal and the plurality of flag signals.

Abstract: A semiconductor memory device includes a charge pumping circuit, a level sensor, an oscillator, and a pumping control signal generator. The charge pumping circuit performs a negative-pumping operation to an external power in order to generate an internal voltage having a level lower than the external power. The level sensor senses a level of the internal voltage corresponding to a level of an adjusted reference voltage during a refresh mode. The oscillator generates a period signal in response to a sensing signal of the level sensor. The pumping control signal generator controls the operation of the charge pumping circuit in response to the period signal.

Abstract: An on die thermal sensor includes a bandgap unit for generating a first voltage containing temperature information, a tracking unit for tracking a voltage level of the first voltage, and a low power control unit for generating a tracking enable signal for enabling the tracking unit and disabling the tracking unit after a minimum tracking operation time of the tracking unit elapses.

Abstract: An internal voltage generator is capable of supplying a stable internal voltage regardless of an unstable external voltage. The internal voltage includes a first level detecting unit configured to detect a voltage level of the internal voltage and output an output power detecting signal, an oscillating unit configured to produce a periodical signal in response to the output power detecting signal, a second level detecting unit configured to detect a voltage level of an external voltage and output a driving power detecting signal, a dividing unit configured to selectively divide the periodical signal in response to the driving power detecting signal and output a divided signal, and a charge pumping unit configured to provide the internal voltage by pumping the external voltage in response to the divided signal.