A Highly Linear Ultra-Low-Area-and-Power CMOS Voltage-Controlled Oscillator for Autonomous Microsystems.

Area of Science:

• Integrated Circuit Design
• Microsystems Engineering
• Sensor Technology

Background:

• Voltage-controlled oscillators (VCOs) are essential for converting analog signals to digital frequencies.
• Designing linear and power-efficient VCOs is challenging for miniaturized systems.
• Smart dust applications require low-power, high-linearity signal conversion.

Purpose of the Study:

• To present a novel VCO design for power-and-area-constrained smart dust systems.
• To achieve a linear frequency response with respect to input voltage.
• To minimize power consumption and physical footprint.

Main Methods:

• Fabrication using 65 nm complementary metal-oxide-semiconductor (CMOS) technology.
• Design focused on minimizing leakage current and peak currents.
• Characterization of frequency range, power consumption, and linearity.

Main Results:

• The VCO occupies a small area of 592 μm2.
• Operates in a frequency range of 43–53 Hz with ultra-low power consumption (4 pW at 0.3 V).
• Demonstrates a quasi-linear frequency response to input voltage, supply voltage, and temperature.

Conclusions:

• The proposed VCO meets the stringent requirements of smart dust systems.
• Its linear response and low power consumption facilitate accurate and efficient data acquisition.
• The design allows for straightforward temperature compensation, enhancing reliability.