Patent ID: 7965149
Filing Date: 2011-06-21
Classification: H03K

Abstract:
1. A resistor-capacitor (RC) oscillator, comprising: a voltage transforming unit configured to transform a power supply voltage to an internal voltage; a current mirroring unit coupled to the voltage transforming unit and being configured to receive the internal voltage to provide two constant current outputs with different phases; a current charging/discharging unit including first and second nodes to receive the two constant current outputs of the current mirroring unit, wherein first and second capacitors coupled to the first and second nodes, respectively, are charged by the two constant current outputs, the current charging/discharging unit further including a first discharge switch and a second discharge switch configured to discharge the first capacitor and the second capacitor respectively; a voltage sensing and outputting unit coupled to the first and second nodes and being configured to sense voltage levels of the first and second nodes and output clock signals when one of the sensed voltage levels is greater than a logic threshold; and a pulse generating unit configured to generate pulse signals in response to the clock signals, wherein the current charging/discharging unit further includes a connection switch to electrically connect the first and second nodes in response to the pulse signals.