US 7,456,767 B2
D/A converter circuit, organic EL drive circuit, and organic EL display
Shinichi Abe, Kyoto (Japan); Jun Maede, Kyoto (Japan); Masanori Fujisawa, Kyoto (Japan); and Akio Fujikawa, Kyoto (Japan)
Assigned to Rohm Co., Ltd., Tokyo (Japan)
Appl. No. 10/594,703
PCT Filed Mar. 28, 2005, PCT No. PCT/JP2005/005673
§ 371(c)(1), (2), (4) Date Sep. 28, 2006,
PCT Pub. No. WO2005/093958, PCT Pub. Date Oct. 06, 2005.
Claims priority of application No. 2004-095005 (JP), filed on Mar. 29, 2004.
Prior Publication US 2007/0273566 A1, Nov. 29, 2007
Int. Cl. H03M 1/00 (2006.01)
U.S. Cl. 341—135  [341/144; 341/145] 12 Claims
OG exemplary drawing
 
1. A D/A converter circuit, which includes a first current mirror circuit having a plurality of output side transistors provided correspondingly to digits of data to be converted and generates an analog current by obtaining in at least one of the output side transistors a current corresponding to weight of a digit of the data, comprising:
a second current mirror circuit connected on an upstream or downstream side of at least one of the output side transistors corresponding to a lower digit of the data, wherein an operating current ratio of the output side transistor of the second current mirror circuit with respect to an input side transistor thereof is set to n:1(where n is a positive integer) and the analog current is generated by obtaining a current corresponding to a weight of the lower digit, which is less than 1, on the output side transistor of the second current mirror circuit.