Dual Integrator Oscillator for Propagation Delay Cancellation
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Solution Overview
Problem
Existing oscillator circuits, particularly relaxation oscillators, suffer from frequency drift due to comparator propagation delay, which affects temperature stability and precision, and are influenced by power supply and process variations.
Innovation Solution
The proposed oscillator circuit employs two integrator-comparator units operating in counter-phase, with complementary signals and adjustable charging currents to accurately measure and cancel the propagation delay, ensuring precise clock signal generation with reduced temperature sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional relaxation oscillator with single integrator-comparator unit is used, then the circuit structure is simple, but frequency precision deteriorates due to comparator propagation delay
Solution Approach 1:
The oscillator is divided into two symmetrical integrator-comparator half-circuits that operate in complementary phases. Each half-circuit generates one phase of the differential clock signal, allowing the propagation delay to be measured and compensated through the symmetrical structure. This segmentation enables frequency precision improvement while maintaining reasonable circuit complexity.
Solution Approach 2:
The patent implements a feedback mechanism where the propagation delay is measured by monitoring the phase relationship between the differential clock signals. The measured delay information is used to adjust the charging currents dynamically, creating a closed-loop system that compensates for delay effects and maintains high frequency precision.
2Use of energy by moving object
If conventional relaxation oscillator is used, then power consumption is low, but temperature stability deteriorates due to frequency drift
Solution Approach 1:
The patent dynamically adjusts the charging current parameters based on measured propagation delay and temperature conditions. By changing the current magnitude adaptively, the oscillator compensates for temperature-induced frequency drift while maintaining efficient power operation. The symmetrical half-circuits ensure that parameter changes affect both phases equally, preserving temperature stability.
3Ease of operation
If conventional relaxation oscillator with fixed charging current is used, then circuit operation is simple, but frequency precision deteriorates due to propagation delay influence
Solution Approach 1:
The charging current is transformed from a fixed value to a dynamically adjustable parameter. The system continuously monitors propagation delay and automatically adjusts the charging current magnitude to compensate for delay effects. This dynamic operation maintains frequency precision without significantly complicating the circuit, as the adjustment is performed through integrated control within the symmetrical half-circuits.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively cancels the comparator propagation delay, improving frequency precision and reducing systematic errors, making the oscillator circuit more stable and less sensitive to temperature changes.
Implementation Method 1
a first integrator-comparator unit (100, 200) adapted to provide a first signal (A1, A2)
Implementation Method 2
The integrator block 10 comprises two switches 11, 12, an inverter 13, a capacitor 14, a comparator 15 and a current source 16
Data Source
AI summary
In an embodiment an oscillator circuit comprises a first integrator-comparator unit, a second integrator-comparator unit, and a logic circuit. The first integrator-comparator unit is prepared to provide a first signal as a function of a first integration of a first charging current and a subsequent comparison of a first integration signal resulting from the first integration with a reference signal. The second integrator-comparator unit is prepared to provide a third signal as a function of a second integration of a second charging current and a subsequent comparison of a second integration signal resulting from the second integration with the reference signal. The logic circuit is adapted to provide a clock signal, a first and a second measurement signal for respectively controlling the first and the second integrator-comparator unit.