Patent ID: 7741893
Filing Date: 2010-06-22
Classification: H03K

Abstract:
1. A dual mode clock generator, comprising: a frequency controller for controlling generation of charge and discharge currents according to first and second currents in a first operation mode and recognizing an initial state and a normal state according to a soft start signal to control generation of charge and discharge currents according to a third current or a fourth current in a second operation mode; a current source unit for generating a charge current according the first current in the first operation mode and generating a charge current according to the third current or the fourth current in the second operation mode depending on the initial state and the normal state through the control of the frequency controller; a capacitor for charging a voltage according to the charge current generated by the current source unit; an oscillation controller for controlling switch-on or switch-off to maintain a charge voltage of the capacitor between a highest reference voltage and a lowest reference voltage; a switch coupled between a ground and a connection node formed between the current source unit and the capacitor, and controlling charging and discharging of the capacitor by performing an on/off operation through the ON or OFF control of the oscillation controller; and a current sink unit coupled between the switch and the ground to generate a discharge current according to the second current in the first operation mode and generate a discharge current according to the third current and the fourth current in the second operation mode depending on the initial state and the normal state and to discharge a charge voltage of the capacitor using the discharge currents through the control of the frequency controller; wherein the frequency controller comprises: