Oscillator Time Base Pulse Inhibition for Precise Frequency Division
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing time bases face challenges in achieving high resolution and low maximum instantaneous error, particularly due to the limitations of frequency adjustment circuits that inhibit clock pulses, leading to disruptions and errors during short test periods.
Innovation Solution
A time base with a divided frequency adjustment circuit that calculates a first real number based on the difference between the determined clocking frequency and a reference frequency, and accumulates a fractional part across inhibition periods to determine the integer number of pulses to inhibit, allowing for precise frequency adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the inhibition period Pinh is increased to increase resolution, then the precision of the time base is improved, but the maximum instantaneous error increases proportionally with Pinh
Solution Approach 1:
The patent applies dynamics by making the inhibition period variable rather than fixed. The system dynamically adjusts the inhibition period based on operational mode: using a first inhibition period for normal operation and a second, shorter inhibition period for test periods. This dynamic adaptation allows the system to maintain high resolution during normal use while minimizing instantaneous errors during testing, thereby resolving the contradiction between precision and reliability.
Solution Approach 2:
The patent changes the parameter of inhibition period duration based on operational context. By switching between a first inhibition period (longer duration) and a second inhibition period (shorter duration), the system optimizes the balance between resolution and instantaneous error. This parameter change strategy enables high precision measurement while controlling the maximum instantaneous error that would otherwise increase proportionally with the inhibition period.
2Reliability
If the inhibition period is short to reduce maximum instantaneous error, then the instantaneous error is reduced, but the resolution and precision of the time base decrease
Solution Approach 1:
The system dynamically selects the appropriate inhibition period based on the operational phase. During normal operation, a first inhibition period is used to achieve high resolution. During test periods, a second inhibition period is activated to minimize instantaneous error. This dynamic switching resolves the contradiction by allowing both long and short inhibition periods to be utilized in different contexts.
Solution Approach 2:
The patent implements periodic action by alternating between different inhibition periods based on the operational mode. The system periodically switches between using a first inhibition period for precision and a second inhibition period for error minimization. This periodic adaptation allows the system to maintain optimal performance characteristics for each operational phase, resolving the precision-error contradiction.
3Measurement precision
If clocking pulses are inhibited in the first division stages to obtain improved resolution, then the resolution is improved, but the clock signal is disrupted during the inhibition interval
Solution Approach 1:
The patent applies local quality by selectively inhibiting clocking pulses only at specific division stages and only during specific inhibition periods rather than continuously or at all stages. The inhibition is locally applied to the second division stage during test periods, allowing other parts of the system to continue operating normally. This localized inhibition maintains resolution improvement while minimizing disruption to the overall clock signal.
Solution Approach 2:
The system uses partial action by inhibiting only a specific number of clocking pulses (Ninh) out of the total pulses in an inhibition period, rather than inhibiting all pulses continuously. This partial inhibition approach achieves the necessary resolution adjustment while allowing the clock signal to continue functioning during non-inhibition intervals, thereby reducing overall disruption to clock signal continuity.
Data Source
AI summary
The time base includes an oscillator generating a periodic signal, a frequency divider circuit formed by a division chain defining several division stages and a circuit for adjusting the divided frequency by inhibiting, in each inhibition period of a plurality of successive inhibition periods, an integer number of clocking pulses at the input of a given stage of the division chain. The time base is arranged to produce, in each inhibition period, a first real number corresponding to the real number of clocking pulses that must be removed to be precise and the adjustment circuit is arranged to calculate, in each inhibition period, a second real number equal to the addition of the first real number and the fractional part of the second real number obtained in the preceding inhibition period, the integer part of this second real number defining the number of clocking pulses to be inhibited in each inhibition period.