Temperature-Compensated Low-Power Oscillator Frequency Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing low power oscillator circuits face challenges in maintaining frequency stability due to temperature variations, requiring additional power-consuming compensation circuits and limiting system voltage, which complicates achieving low power and low frequency drift simultaneously.
Innovation Solution
A low power oscillator circuit with a temperature compensation circuit that includes a current supply unit, a temperature compensation circuit with a unidirectional conduction element and resistor string, and a bias circuit, which balances the effect of temperature on delay time by adjusting threshold voltages and reference currents, allowing operation with lower system voltage and reduced transistor count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a temperature compensation circuit is added to stabilize frequency, then frequency stability is improved, but power consumption increases
Solution Approach 1:
The patent combines the temperature compensation function with the existing bias circuit by sharing the same current path and using common transistors. The bias circuit generates a bias current that automatically compensates for temperature effects on the oscillating signal delay time, eliminating the need for a separate compensation circuit and reducing power consumption while maintaining frequency stability.
Solution Approach 2:
The bias circuit is designed to serve multiple functions: it provides bias current for the oscillating signal generation and simultaneously performs temperature compensation. By making the bias circuit multi-functional, the patent avoids adding dedicated compensation components that would increase power consumption, while still achieving the goal of stabilizing frequency against temperature variations.
2Power
If system voltage is increased to drive the oscillator, then oscillation amplitude is improved, but power consumption increases
Solution Approach 1:
The patent changes the parameter of bias current magnitude to optimize oscillation amplitude without increasing system voltage. By adjusting the bias current generated by the bias circuit, the oscillation amplitude is sufficient to drive the oscillator effectively while maintaining low supply voltage, thus reducing power consumption while achieving adequate oscillation strength.
3Use of energy by moving object
If the number of MOS transistors is reduced for low power, then power consumption is decreased, but frequency compensation capability is worsened
Solution Approach 1:
The patent merges the frequency compensation capability into the bias circuit itself, using the same transistors that generate bias current to provide temperature compensation. This integration allows the circuit to maintain frequency compensation capability with fewer transistors, as the compensation function is achieved through the bias circuit's inherent characteristics rather than additional dedicated components.
Data Source
AI summary
A low power oscillator circuit with temperature compensation is illustrated. A current supply unit of an oscillator used to output an output current which is proportional to a reference current. As the temperature is increased, both a first threshold and the reference current of a unidirectional conduct in the temperature compensation circuit are decreased. Because a delay time of the oscillating signal is proportional to the first threshold voltage, and the delay time is inversely proportional to the reference current, the effects of the first threshold voltage and the reference current on the delay time are canceled, and the delay time of the oscillating signal is not affected by the temperature.