Design of Cascode Current Mirror using CMOS Technology for Low Power Application

What is it about?

This study focuses on the design and optimization of a low-power cascode current mirror using the GPDK 45nm CMOS technology node in Cadence Virtuoso. Current mirrors with high output impedance are essential for applications such as biomedical electronics that operate at low supply voltages. The proposed design enhances current mirroring accuracy while significantly reducing power consumption. Simulation results demonstrate that the proposed cascode current mirror consumes only 48 µW, compared to 74.186 µW in a conventional cascode mirror, with a noticeable improvement in output resistance. A small-signal model and mathematical analysis validate the circuit’s performance. This makes the design suitable for energy-efficient and low-voltage analog systems.

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Photo by Christian Wiediger on Unsplash

Photo by Christian Wiediger on Unsplash

Why is it important?

It is important because it advances energy-efficient, accurate analog design tailored for modern low-voltage applications, meeting both technical and real-world demands in areas like IoT, healthcare, and portable electronics. Power Efficiency As electronic systems increasingly demand energy-efficient solutions, especially in portable and battery-operated devices, minimizing power consumption has become a design priority. The proposed circuit achieves a substantial reduction in power consumption, using only 48 µW, which makes it highly suitable for low-power VLSI applications. Enhanced Current Accuracy A high output impedance in current mirrors is essential to maintain accurate current replication, particularly under varying load conditions. The cascode structure used in this design ensures improved current matching, leading to greater circuit reliability and stability. Suitability for Low-Voltage Applications Many modern systems, especially in biomedical and sensor-based applications, operate at low supply voltages. Traditional current mirrors suffer from performance degradation in such environments. The proposed design addresses this limitation by offering reliable performance in subthreshold and low-voltage regimes. Relevance in Deep Submicron Technologies With the transition to deep submicron nodes like 45nm, designers face challenges such as short-channel effects and reduced voltage headroom. This work demonstrates how a cascode current mirror can be optimized in GPDK45 technology, maintaining functionality and efficiency despite the scaling limitations. Foundation for Analog System Design Current mirrors are fundamental building blocks in analog circuits, including operational amplifiers, biasing circuits, and analog-to-digital converters. Improvements in this basic component translate directly into enhanced overall system performance. Sustainable and Scalable Design Reducing power consumption not only improves efficiency but also contributes to environmental sustainability. The scalable nature of the proposed design makes it applicable to a wide range of modern VLSI applications, from medical electronics to smart IoT devices.