Methods for Designing High-Precision Relaxation Oscillator.

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• Analog Electronics

Background:

• Relaxation oscillators are fundamental in electronic systems but susceptible to performance variations.
• Comparator delay, offset voltage, and temperature drift in resistors degrade oscillator precision.
• Existing techniques often struggle to mitigate these combined effects effectively.

Purpose of the Study:

• To propose and validate novel techniques for high-precision, low-power relaxation oscillator design.
• To address and minimize the impact of critical error sources in relaxation oscillators.
• To improve the stability and accuracy of 8 MHz relaxation oscillators.

Main Methods:

• Development of a low-power delay time cancellation (LPDTC) technique.
• Implementation of a current ratio adjustment (CRA) method.
• Design and simulation of an 8 MHz open-loop relaxation oscillator using a 40 nm CMOS process.

Main Results:

• Achieved a line sensitivity of 0.38%/V, indicating robust power supply rejection.
• Demonstrated a temperature sensitivity of 43 ppm/°C across a wide temperature range (-40 °C to 125 °C).
• Effectively reduced impacts of comparator delay, offset voltage, and resistor variations.

Conclusions:

• The proposed LPDTC and CRA methods enable the design of high-precision, stable relaxation oscillators.
• These techniques offer a significant improvement in performance over conventional methods.
• The validated 8 MHz oscillator design is suitable for applications requiring high accuracy and low power consumption.