Innovative feedback approach for high-performance low-voltage current mirror

The paper presents an approach to increase the performance in terms of input and output resistance of a low voltage flipped voltage follower (FVF) based current mirror. The proposed technique consists of substituting the main output transistor with a network of transistors in a feedback arrangement, designed to improve the output resistance. Furthermore, a low saturation onset transistor approach is used to improve the performance. Such an approach also helped in reducing the input resistance of the current mirror, which ranges in ohms. A wide current range of up to 1 mA is achieved at a minimal current transfer error of 0.38 %. This feedback mechanism-based current mirror exhibits an output resistance of 29.61 GΩ, an input resistance of 30.45 Ω, and a bandwidth of 1.464 GHz. The proposed current mirror runs on ±0.5 V supply voltage. The robustness of the proposed circuit is evaluated through process corner analysis, temperature mismatch assessment, and Monte-Carlo simulations. The performance characteristics of the proposed current mirror have been validated and simulated using Cadence Virtuoso and Spectre simulations on 0.18 μm UMC technology. The validation process included both pre-layout and post-layout simulation results.