0.5 V, Low-Power Bulk-Driven Current Differencing Transconductance Amplifier

Area of Science:

• Electronics
• Analog Integrated Circuit Design
• Signal Processing

Background:

• Low-power and low-voltage analog circuit design is crucial for modern portable and battery-operated electronic systems.
• Current Differencing Transconductance Amplifiers (CDTAs) are versatile active building blocks for analog signal processing.
• Existing CDTA designs often face limitations in terms of power consumption and operating voltage.

Purpose of the Study:

• To present a novel low-power, low-voltage current differencing transconductance amplifier (CDTA).
• To demonstrate the application of the proposed CDTA in realizing a current-mode universal filter.
• To achieve a filter with independent control over its parameters and without component-matching conditions.

Main Methods:

• Utilizing the bulk-driven MOS transistor (BD-MOST) technique operating in the subthreshold region for low-voltage and low-power operation.
• Designing the CDTA using 0.18 µm CMOS technology.
• Implementing a current-mode universal filter using the proposed CDTA, capable of realizing five standard filter functions.

Main Results:

• The proposed CDTA operates at a low supply voltage of 0.5 V and consumes only 1.05 μW of power.
• The current-mode universal filter realizes low-pass, band-pass, high-pass, band-stop, and all-pass responses from a single circuit configuration.
• The filter exhibits low-input and high-output impedance, uses grounded capacitors, and allows orthogonal control of natural frequency and quality factor.
• SPICE simulations confirm the feasibility and functionality of the CDTA and the filter circuit.

Conclusions:

• The developed BD-MOST based CDTA offers a significant advancement in low-power, low-voltage analog circuit design.
• The proposed current-mode universal filter provides a flexible and efficient solution for various filtering applications.
• The circuit's ability to achieve multiple filter functions and independent parameter control makes it highly suitable for integrated circuit implementations.