Power-On Sequencing Using Stable Reference Voltage Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power-on sequencing methods in low-power devices often result in insufficient voltage supply, leading to incorrect operation or unpredictable conditions due to variations in temperature and fabrication processes, which can cause the VCC trigger voltage to be too low for proper functioning of high-voltage circuitry like non-volatile memories.
Innovation Solution
A reference voltage generator independent of temperature and process variations is used to ensure a stable voltage reference, enabling system circuitry only when the supply voltage exceeds this reference, thereby guaranteeing sufficient power for nominal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an internal voltage reference dependent on device thresholds is used for power-on detection, then the circuit can operate at low power supply levels, but the trigger voltage becomes sensitive to temperature and processing variations, leading to unreliable operation
Solution Approach 1:
The patent introduces an external reference voltage source as an intermediary between the power supply and the power-on detection circuit. This external reference voltage serves as a stable mediator that is not affected by temperature or processing variations, allowing the system to reliably detect when the power supply reaches the required threshold level without being influenced by device parameter variations.
2Loss of time
If the VCC trigger voltage is set low to enable early operation, then power-on sequencing starts earlier, but the voltage may be insufficient for high-voltage circuitry like charge pumps and non-volatile memories to operate correctly
Solution Approach 1:
The patent changes the reference parameter from an internal voltage reference (dependent on device thresholds) to an external reference voltage source. This parameter change allows the trigger voltage to be set at a higher, more reliable level that ensures sufficient voltage for all circuitry including charge pumps and non-volatile memories, while still enabling timely power-on sequencing through proper external reference selection.
Data Source
AI summary
Apparatus, systems, and methods are disclosed that operate to trigger a reference voltage generator from a supply voltage detector, compare an output voltage level from the reference voltage generator with a supply voltage, and to generate an enable signal when the supply voltage is greater than the output voltage level. Additional apparatus, systems, and methods are disclosed.