Differential Amplifier Duty-Cycle Control for Clock Generators
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Solution Overview
Problem
Existing clock signal generators face issues with excessive power consumption due to the need to correct duty cycle variations, which can lead to timing errors and failure to meet performance specifications, especially at high frequencies.
Innovation Solution
The proposed solution involves using a differential amplifier as an input buffer controlled by a DCC Detect & Control circuit to adjust the duty cycle of clock signals, eliminating the need for a large number of logic gates and static trim circuits, thereby reducing power consumption and achieving precise duty cycle correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a large number of series-coupled logic gates or inverters are used to delay and adjust the clock signal, then the duty cycle can be corrected, but power consumption increases substantially
Solution Approach 1:
The patent changes the operational parameters of existing circuit components (delay elements, buffers, inverters) by controlling their switching thresholds and delay characteristics through bias voltages and control signals, rather than increasing the number of components. This allows duty cycle correction through parameter adjustment of a fixed, small number of components.
Solution Approach 2:
The patent replaces the mechanical approach of adding more physical logic gates in series with an electronic control approach using voltage-controlled delay elements and buffered feedback circuits. This substitution reduces the physical component count while achieving the same functional goal of duty cycle correction.
2Speed
If the frequency of clock signals is increased to improve performance, then processing speed improves, but duty cycle variations introduce unacceptable timing errors
Solution Approach 1:
The patent implements feedback mechanisms where the output clock signal is fed back through buffered delay paths to control the switching thresholds and delay characteristics of the circuit. This feedback allows the circuit to automatically compensate for duty cycle variations even at high frequencies, maintaining timing accuracy.
Solution Approach 2:
The patent makes the circuit characteristics dynamic by using voltage-controlled delay elements and buffers whose parameters can adjust in real-time based on the input signal conditions. This dynamic adaptation allows the circuit to maintain precise duty cycle control across varying frequencies.
3Manufacturing precision
If duty cycle correction circuits are added to correct variations, then timing accuracy improves, but device complexity increases
Solution Approach 1:
The patent designs the circuit elements (buffers, delay elements, inverters) to serve multiple functions simultaneously: signal transmission, delay control, threshold adjustment, and feedback regulation. This multi-functionality reduces the need for separate dedicated correction circuits, thereby reducing overall device complexity.
Solution Approach 2:
The patent merges the duty cycle correction function with the existing clock signal distribution and buffering infrastructure. Rather than adding separate correction circuits, the correction functionality is integrated into the signal path using the same physical components that would otherwise be required for signal distribution.
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 significantly reduces power consumption while maintaining accurate duty cycle correction, ensuring that clock signals have a stable 50% duty cycle or other specific values, thus preventing timing errors and meeting performance specifications.
Implementation Method 1
a differential amplifier as an input buffer controlled by a DCC Detect & Control circuit to adjust the duty cycle of clock signals
Data Source
AI summary
A differential amplifier may be configured to have a duty cycle and/or gain that is adjustable, such as by adjusting the switch points of circuitry in the differential amplifier. The differential amplifier may alternatively or additionally have a hysteresis function by, for example, using a signal feedback from the output of the amplifier to adjust the switch points of circuitry in the differential amplifier. The differential amplifier may be used for a variety of purposes, such as in an input buffer or delay line, either of which may be used, for example, in a clock generator circuit.