Patent ID: 8242853
Filing Date: 2012-08-14
Classification: H03L

Abstract:
1. A low headroom oscillator, comprising: a first and a second capacitor; at least two nMOS devices, the two nMOS devices selectably discharging the first and second capacitors, wherein if one of the nMOS devices is turned on, the other nMOS device is turned off; at least two pMOS devices connected to the first and second capacitors, the two pMOS devices selectably charging the capacitors, wherein if one of the pMOS devices is turned on, the other pMOS device is turned off, the two pMOS devices being connected at gates of the two pMOS devices through a first inverter; a comparator and a hysteresis comparator, the comparator and the hysteresis comparator comparing a charge on the first and second capacitors to a reference voltage, wherein the hysteresis comparator tunes a frequency and a duty cycle of the oscillator, an output terminal of at least one of the comparator and the hysteresis comparator being connected to the first inverter; and a current source that biases the two pMOS devices.