Formal Analysis Of High-Performance Stabilized Active-Input Current Mirror

The active input topology has been frequently proposed to boost the speed of current mirrors. However, inherent stability issues constrain the maximum reachable speed, sometimes making this solution inefficient. In this paper, we present a modified version of the active-input, which improves the stability region and permits much better speed improvement with low additional complexity and power consumption. Because of the wide range of possible applications, we choose to develop a dedicated formalism based on a systematic and generic approach, intended to achieve the best speed-power performance in stabilized active-input current mirror design. To validate the calculation flow, we compare the simple diode-connected mirror and the stabilized active-input topology with identical MOS devices. An use-case example using our formalism shows that the proposed stabilized active-input current mirror exhibits a speed improvement of more than 30 times the equivalent diode-connected current mirror, with an extra bias current consumed of 5% of the output DC current.