Patent ID: 6107889
Filing Date: 2000-08-22
Classification: G05F,H03L

Abstract:
A charge pump circuit comprising:a reference current loop operable for defining a reference current through a first biasing transistor and having a first low impedance output associated therewith;a circuit output node having an output voltage associated therewith;a first output transistor coupled to said circuit output node which is driven by said first low impedance output of said reference current loop to establish an output current that is proportional to said reference current therethrough;a replication feedback loop coupled to said reference current loop at a coupling node and operable for replicating said output voltage at said coupling node such that said reference current is defined in a second biasing transistor and having a second low impedance output; anda second output transistor coupled to said circuit output node which is driven by said second low impedance output of said replication feedback loop to establish an output current that is proportional to said reference current therethrough, whereinsaid reference current loop comprises a first operational amplifier having a positive terminal coupled to a reference voltage, a negative terminal coupled to said first biasing transistor, and an output defining said first low impedance output, and said first low impedance output is selectively switched to said first output transistor.