Temperature-Controlled Oscillator Circuit for Stable Clock Frequency
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Solution Overview
Problem
Existing oscillators, such as crystal oscillators, suffer from frequency variance due to temperature changes and environmental influences, necessitating costly solutions like oven-controlled crystal oscillators (OCXOs) to maintain stability.
Innovation Solution
An oscillating device that captures transient state through input voltage, using a MOSFET and temperature sensing circuit to generate a frequency compensation signal without measuring power consumption, incorporating components like ADC, processor, and PLL to adjust clock signals based on voltage-frequency relationships.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oven controlled crystal oscillators (OCXOs) are used to maintain frequency stability, then frequency stability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the temperature control function from the complex OCXO system and implements it through a simplified temperature-controlled circuit that directly controls the heater based on sensed temperature, eliminating the need for complex manufacturing while maintaining frequency stability
Solution Approach 2:
The oscillating device monitors its own temperature through the temperature sensing circuit and automatically adjusts the heater power accordingly, enabling self-regulated temperature control without external complex control systems, thus improving frequency stability while reducing manufacturing complexity
2Measurement precision
If power consumption measurement is implemented for temperature compensation, then frequency compensation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent uses the input voltage to the heater as an intermediary parameter that directly reflects the transient thermal state. By monitoring this voltage through the ADC, the system achieves accurate frequency compensation without implementing complex power consumption measurement circuits
Solution Approach 2:
The patent changes the measurement parameter from power consumption (which requires complex measurement) to input voltage (which is simpler to measure). The voltage-frequency relationship captures the transient thermal state, providing accurate frequency compensation with reduced device complexity
3Device complexity
If transient state capture is implemented without power measurement, then device complexity is reduced, but measurement precision may be affected
Solution Approach 1:
The patent replaces the electrical power measurement system with a voltage-based transient state capture approach. By measuring the input voltage to the heater and using the voltage-frequency relationship, the system achieves frequency compensation with simpler circuitry while maintaining precision through the direct correlation between voltage and thermal state
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
Effectively reduces frequency variation by dynamically compensating for temperature changes, achieving stable clock signals without the need for direct power measurement, thus reducing costs and improving stability.
Implementation Method 1
The temperature sensing circuit is electrically connected to the gate of the MOSFET. The temperature-controlled circuit is configured to sense the ambient temperature to generate an input voltage that is temperature-dependent on the ambient temperature
Implementation Method 2
The temperature-controlled circuit includes a metal-oxide-semiconductor field-effect transistor (MOSFET) and a temperature sensing circuit. The drain of the MOSFET is directly electrically connected to the heater. The MOSFET and the heater are electrically connected between a high voltage terminal and a low voltage terminal.
Implementation Method 3
The oscillator is configured to generate a first clock signal whose frequency is temperature-dependent on the ambient temperature. The temperature-controlled circuit is directly electrically connected to the heater and provide the input voltage for the heater
Data Source
AI summary
An oscillating device is arranged in an environment having an ambient temperature. The oscillating device includes a heater, an oscillator, and a temperature-controlled circuit. The oscillator is configured to generate a first clock signal whose frequency is temperature-dependent on the ambient temperature. The temperature-controlled circuit is directly electrically connected to the heater. The temperature-controlled circuit senses the ambient temperature to generate an input voltage that is temperature-dependent on the ambient temperature and provides the input voltage for the heater. The temperature-controlled circuit includes a MOSFET and a temperature sensing circuit. The drain of the MOSFET is directly electrically connected to the heater. The MOSFET and the heater are electrically connected between a high voltage terminal and a low voltage terminal. The temperature sensing circuit is electrically connected to the gate of the MOSFET.