Patent ID: 9583631
Date: 2017-02-28
CPC Classifications: H01L,H03M

Claim:
1. A current source device, comprising: a plurality of current source units, arranged along a plurality of rows and a plurality of columns of a current source array, wherein each of the current source units comprises a first amount of sub-units, wherein each of the sub-units comprises a second amount of first-type transistors, wherein the first-type transistors are coupled in series with each other and the sub-units are coupled in parallel with each other; a plurality of least significant bits, wherein each of the least significant bits comprises a third amount of the current source units; and a plurality of most significant bits, wherein each of the most significant bits comprises a fourth amount of the current source units, wherein the fourth amount is the third amount multiplied by a positive integer, wherein each of the current source units is constructed by a fifth amount of the first-type transistors, such that a poly silicon density of the first-type transistor is uniform to reduce an influence of a gradient in the poly silicon density of the current source units and to increase an output impedance of each of the current source units.