Patent ID: 7279961
Filing Date: 2007-10-09
Classification: H02M

Abstract:
1. A circuit for providing an intermediate voltage, including: a charge pump generating a first voltage higher than the intermediate voltage; a regulator circuit providing a first regulated voltage higher than the intermediate voltage, the regulator circuit formed from a first comparator having a reference voltage coupled to one input and a voltage divider driven from the charge pump coupled to the other input, the first comparator driving a first MOS transistor coupled between the charge pump and ground and having a gate driven by the comparator; and a downconverter circuit using the first regulated voltage to provide the intermediate voltage from the first voltage, the downconverter circuit formed from a second comparator having the reference voltage coupled to one input and a voltage divider coupled to the other input, the second comparator driving a second MOS transistor configured as a source follower having a gate driven by the output of the second comparator, a drain coupled to the output of the charge pump, and a source coupled to the voltage divider.