0.5 V Versatile Voltage- and Transconductance-Mode Analog Filter Using Differential Difference Transconductance...

Area of Science:

• Analog electronics
• Integrated circuit design
• Filter theory

Background:

• Traditional analog filters often rely on resistors, limiting miniaturization and integration.
• Achieving both high-input and low-output impedance (for VM) and high-input and high-output impedance (for TM) in a single topology is challenging.
• Existing filter designs may require circuit modifications to switch between voltage-mode and transconductance-mode operations.

Purpose of the Study:

• To propose a new, versatile analog filter topology.
• To demonstrate resistor-less implementation using DDTAs for integrated circuits.
• To achieve both voltage-mode (VM) and transconductance-mode (TM) operations with desirable impedance characteristics in a single circuit.

Main Methods:

• The proposed filter utilizes three differential-difference transconductance amplifiers (DDTAs) and two grounded capacitors.
• The design avoids the use of resistors, facilitating integrated circuit implementation.
• Simulations were performed using Cadence with 0.18 µm CMOS technology.

Main Results:

• The filter topology provides high-input and low-output impedances for VM operation and high-input and high-output impedances for TM operation without modification.
• A quadrature oscillator can be realized by adding a feedback loop.
• The single topology supports five standard filtering responses: low-pass, high-pass, band-pass, band-stop, and all-pass.
• Electronic control over natural frequency and oscillation conditions is achieved.
• The circuit operates at a low supply voltage of 0.5 V.

Conclusions:

• The proposed resistor-less analog filter offers a versatile and efficient solution for integrated circuit applications.
• The design successfully integrates VM and TM operations with tunable filtering responses.
• The circuit's low power consumption and high performance make it suitable for modern electronic systems.