A 0.18 μm CMOS LDO Regulator for an On-Chip Sensor Array Impedance Measurement System

Area of Science:

• Integrated Circuit Design
• Analog Electronics
• Biomedical Instrumentation

Background:

• Battery-operated micro-instruments require highly efficient and stable power management solutions.
• Impedance spectrometry demands precise voltage regulation for accurate measurements.
• Existing voltage regulators may not meet the size, power, and performance constraints of portable systems.

Purpose of the Study:

• To design and validate a fully integrated 0.18 μm CMOS Low-Dropout (LDO) Voltage Regulator.
• To meet the stringent power supply requirements of a multichannel CMOS micro-instrument for impedance spectrometry.
• To achieve a compact, low-power, and high-performance LDO suitable for portable applications.

Main Methods:

• Implementation of a compact LDO topology in a 0.18 μm CMOS process.
• Characterization of the LDO's performance over a wide temperature range (-40°C to 100°C).
• Evaluation of quiescent current, current efficiency, and transient response.

Main Results:

• The LDO provides a stable 1.8 V output from a 3.6 V to 1.94 V battery input.
• Achieved a compact chip area of less than 0.10 mm².
• Demonstrated a low quiescent current of 7.45 μA with 99.985% current efficiency.
• Exhibited state-of-the-art Figures of Merit (FoMs) for regulating-transient performance.

Conclusions:

• The developed LDO is highly suitable for battery-operated impedance spectrometry micro-instruments.
• The compact size and high efficiency enable the development of portable System on Chip (SoC) platforms.
• This work contributes to the advancement of portable biosensing and diagnostic devices.