Oscillation Circuit Feedback Control for Fast Start-Up Stability
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Solution Overview
Problem
Existing oscillation circuits face issues with high power consumption, slow start-up, and instability in oscillation frequency and amplitude due to switching between different circuit configurations, particularly in inverter-based Pierce and Colpitts oscillation circuits.
Innovation Solution
An oscillation circuit design incorporating a differential amplifier circuit on the oscillation loop, with a feedback path and feedback amount adjusting circuit, allows for high-speed start-up and high-frequency oscillation by controlling the feedback amount and selectively operating the differential amplifier circuit only during start-up.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a source-follower-based Colpitts oscillation circuit is used, then power consumption is reduced, but oscillation start-up becomes slower
Solution Approach 1:
The patent applies dynamics by making the amplifier circuit's operating state changeable - during start-up, the amplifier operates in a high-gain state to enable fast oscillation build-up, and during steady-state, it transitions to a low-power state. This dynamic adjustment of the amplifier's operating characteristics allows the circuit to achieve both fast start-up and low power consumption at different time phases.
Solution Approach 2:
The patent implements periodic action through the oscillatory nature of the circuit itself, where the amplifier circuit periodically adjusts its operation between start-up phase (requiring high gain) and steady-state phase (requiring low power). The oscillation loop with feedback path enables this periodic transition, allowing the system to cycle through different operational modes to optimize both speed and energy efficiency.
2Speed
If switching between Pierce circuit and Colpitts oscillation circuit is implemented, then start-up speed improves, but discontinuities in output voltage amplitude and oscillation frequency occur
Solution Approach 1:
The patent merges the advantages of both Pierce and Colpitts circuits by integrating a feedback path that combines the output signal with the input of the amplifier circuit. This merging of signal paths allows the circuit to achieve fast start-up characteristics while maintaining stable output voltage amplitude and oscillation frequency, eliminating the discontinuities that occur when switching between separate circuit configurations.
Solution Approach 2:
The patent applies feedback by introducing a feedback path that feeds a portion of the output signal back to the amplifier circuit's input. This feedback mechanism automatically stabilizes the output voltage amplitude and oscillation frequency during transitions, preventing the discontinuities that would otherwise occur when switching between different oscillation circuit modes.
3Use of energy by moving object
If a source-follower-based Colpitts oscillation circuit is used, then power consumption is reduced, but oscillation cannot be carried out at high frequencies
Solution Approach 1:
The patent applies parameter changes by modifying the amplifier circuit's gain characteristic dynamically. During high-frequency operation, the amplifier operates in a high-gain state to provide sufficient negative resistance for oscillation at high frequencies. During steady-state low-power operation, the gain is reduced. This parameter adjustment allows the circuit to achieve both low power consumption and high-frequency oscillation capability.
Data Source
AI summary
The oscillation circuit 1 comprises: an oscillator X1; a first capacitance CF having one end connected to the oscillator X1; a second capacitance CO having one end connected to the other end of the first capacitance CF; an output terminal Vo connected to a connection point N2 of the first capacitance CF and the second capacitance CO; an amplifier circuit A1 connected between a node between the oscillator X1 and the first capacitance CF and a connection point N2 of the first capacitance CF and the second capacitance CO to form an oscillation loop together with the first capacitance CF; a differential amplifier circuit A2 arranged on the oscillation loop; and a feedback path 3 configured to feed a part of an output on the output terminal Vo to the differential amplifier circuit A2.