Patent ID: 6734708
Filing Date: 2004-05-11
Classification: G05F,H03L

Abstract:
A controllable current source circuit, comprising:an output; a supply voltage terminal and a reference potential terminal; a connection node; a first driver stage having a first controlled path containing a first transistor and a second driver stage having a second controlled path containing a second transistor having a control terminal, said first and second controlled paths connected in series between said voltage supply terminal and said reference potential terminal, and said second driver stage forming a part of a first current mirror circuit causing a constant stabilized current to flow in said second driver stage only said first driver stage switching on and off in dependence on an input signal, and said second driver stage being switched on and carrying a stabilized current; at least two current paths connected between said connection node and said reference potential terminal, each of said at least two current paths including a further transistor having a respective control terminal, said control terminals of said further transistors being connected to said control terminal of said second transistor; a phase comparator stage being connected between said connection node and said voltage supply terminal and including a switching element and at least two current paths connecting said switching element to said voltage supply terminal; and a second current mirror circuit having a primary side and a secondary side; one of said current paths of said phase comparator stage including said primary side of said second current mirror circuit; and said secondary side of said second current mirror circuit including said first transistor.