Performance Analysis of Constant Current Source for Different Aspect Ratio

The availability of large numbers of closely matched devices has led to the development of special circuit techniques that depend on the similarity of device characteristics for proper operation. These matched circuit design techniques are used throughout analog circuit design and produce high-performance circuits that require very few resistors. One of the most important of the IC techniques is the current mirror circuit, in which the output current replicates, or mirrors, the input current. Multiple copies of the replicated current can be generated, and the gain of the current mirror can be controlled by scaling the W/L ratios of MOSFETs. The current accuracy is a very important index for a high performance circuit. In this paper, proposed circuit has been designed and simulated on 0.03 μm channel length with Micro wind software. Simulated results for varying aspect ratio, W/L 1, 2 and 3 produce drain current, Id of 300, 600 and 925 μA at 1V Vd and Vg respectively.