Direct Current to Digital Converter (DIDC): A Current Sensor.

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• Semiconductor Technology

Background:

• Traditional current measurement in System-on-Chip (SoC) designs faces limitations including high power consumption, large area, and reliance on intermediate analog signals.
• Existing methodologies often require complex calibration and are not optimized for modern, compact semiconductor technologies.

Purpose of the Study:

• To introduce a systematic design for a Direct Current-to-Digital Converter (DIDC) that overcomes the limitations of conventional current measurement techniques in SoCs.
• To achieve precise, energy-efficient, and area-optimized current sensing for advanced semiconductor applications.

Main Methods:

• The proposed DIDC utilizes a current mirror in a cascode topology for current management.
• Successive Approximation Register (SAR) logic is employed to control multiple binary-sized current branches for precise measurement.
• A simple comparator and isolation circuit are integrated for accurate sensing.

Main Results:

• The fabricated DIDC (TSMC 180 nm) achieves 8-bit precision without nonlinearity calibration.
• Demonstrates remarkable energy efficiency with 1.52 pJ energy per conversion and 117 µW power consumption.
• Achieves a compact chip area of 0.016 mm², significantly reducing footprint.

Conclusions:

• The developed DIDC offers a scalable and efficient solution for current measurement in next-generation semiconductor technologies.
• Enables online measurements during standard operations and in-field conditions, enhancing SoC performance and reliability.
• Represents a promising advancement for reducing power and area in integrated current sensing solutions.