US 7,321,326 B2
Current source cell and D/A converter using the same
Shigeo Imai, Yokohama (Japan)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan)
Filed on Dec. 12, 2005, as Appl. No. 11/302,000.
Claims priority of application No. 2004-359704 (JP), filed on Dec. 13, 2004.
Prior Publication US 2006/0192705 A1, Aug. 31, 2006
Int. Cl. H03M 1/66 (2006.01)
U.S. Cl. 341—144  [341/135; 341/136] 11 Claims
OG exemplary drawing
 
1. A current source cell comprising:
first and second transistors which are complementarily switched by a control signal; a constant current source which is commonly connected to one ends of current paths of the first and second transistors;
third and fourth transistors which are respectively connected between the other ends of the current paths of the first and second transistors and first and second output terminals, and which being in normally conducting states; and
an inversion amplifier having an input terminal which is commonly connected to the one ends of the current paths of the first and second transistors, and having output terminal which is commonly connected to control terminals of the third and fourth transistors:
wherein the inversion amplifier comprises a fifth transistor and a second constant current source serially connected with each other, a control terminal of the fifth transistor being commonly connected to one ends of the current paths of the first and second transistors, and a connection node between the fifth transistor and the second constant current source being commonly connected to control terminals of the third and fourth transistors.