Programmable Gain Timer Circuit for Accurate Reset Timeout Tuning
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Solution Overview
Problem
Existing supervisory circuits with tunable timer circuits using external capacitors face accuracy issues due to poor absolute value and temperature/voltage coefficients, leading to unreliable reset timeout periods.
Innovation Solution
A timer circuit utilizing a tunable resistor with programmable gain circuitry and comparator circuits to adjust the comparator threshold, allowing for precise control of the timeout period by varying the resistor value, thereby improving timing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If external capacitors are used to provide tunable timeout periods, then flexibility and tunability are improved, but timing accuracy deteriorates due to poor absolute value and temperature/voltage coefficients
Solution Approach 1:
The patent changes the tuning parameter from capacitor value to resistor value. By using a tunable resistor instead of a tunable capacitor, the circuit maintains flexibility in adjusting the timeout period while achieving superior timing accuracy. Resistors have better absolute value stability and lower temperature coefficients compared to capacitors, thus resolving the accuracy issue while preserving tunability through programmable resistor selection.
2Ease of operation
If external capacitors are used for timeout timing, then external tunability is achieved, but reliability deteriorates due to unstable timing under temperature and voltage variations
Solution Approach 1:
The patent substitutes the tuning element from capacitor to resistor, leveraging the superior environmental stability of resistors. The tunable resistor maintains consistent timing characteristics across temperature and voltage variations, thereby improving reliability while preserving external programmability for different timeout requirements.
3Manufacturing precision
If fixed on-chip timer circuits are used, then manufacturing precision is improved, but adaptability deteriorates as timeout periods cannot be adjusted
Solution Approach 1:
The patent transforms the fixed timeout circuit into a dynamic, programmable system. By incorporating a tunable resistor that can be programmed to different resistance values, the timer circuit adapts to various timeout requirements while maintaining manufacturing precision through controlled resistor fabrication processes.
Solution Approach 2:
The patent creates a universal timer circuit that can serve multiple applications with different timeout requirements. The programmable resistor allows the same circuit design to be configured for various timeout periods, making it adaptable across different supervisory and timing applications while maintaining consistent manufacturing standards.
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
The solution provides a more accurate and stable reset timeout period with reduced dependence on on-chip bias currents and improved temperature stability, enabling flexible and reliable timing in supervisory circuits.
Implementation Method 1
a resistor coupled to a current source to provide a current to the resistor to produce a resistor voltage level
Implementation Method 2
A programmable gain circuit is coupled to amplify the resistor voltage level based upon a selected gain
Implementation Method 3
A comparator circuit configured to transition between providing a signal having a first value and providing a signal having a second value based at least in part upon comparisons of a capacitor voltage level with the amplified resistor voltage level and with a second reference voltage
Implementation Method 4
A reactive circuit element excitation circuit is configured to reverse excitation of the capacitor in response to the comparator circuit transitioning between providing the signal having the first value and providing the signal having the second value
Data Source
AI summary
A timer circuit is provided comprising: a resistor; a programmable gain circuit coupled to amplify the reference level based upon a resistor and a selected gain; a detection circuit coupled to identify the amplified reference level based upon a resistor; a selection circuit configured to select the gain based at least in part upon the identified amplified reference level based upon a resistor; a comparator circuit configured to transition between providing a signal having a first value and providing a signal having a second value based at least in part upon comparisons of a reactive circuit element excitation level with the amplified reference level based upon a resistor and with a second reference level; and reactive circuit element excitation circuit configured to reverse excitation of the reactive circuit element in response to the comparator circuit transitioning between providing the signal having the first value and providing the signal having the second value.