Patent ID: 7859347
Filing Date: 2010-12-28
Classification: G11C

Abstract:
1. A self refresh oscillation apparatus, comprising: a voltage detection unit for detecting a voltage level of a power supply voltage and generating first and second period control signals according to the detected voltage level; and an oscillation unit for receiving the first and second period control signals, and for generating an oscillation signal having a predetermined constant period in response to a self refresh command, wherein a logic level of the first period control signal indicates that the power supply voltage is greater than a first reference voltage, a logic level of the second period control signal indicates that the power supply voltage is greater than a second reference voltage, and the voltage level of the first reference voltage is greater than that of the second reference voltage; and wherein the period of the oscillation signal has the predetermined constant period regardless of the variation of the voltage level of the power supply voltage by adjusting a resistance of the oscillation unit according to the logic levels of the first and second period control signals as the voltage level of the power supply voltage changes.