Multi-Supply Voltage Detection Circuit With Two-Comparator Threshold Switching
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Solution Overview
Problem
Existing circuits for detecting multiple supply voltages consume excessive power due to the need for multiple comparators, which is a significant performance issue.
Innovation Solution
A circuit comprising a supply voltage divider, a state machine, and two comparators, where the threshold selector sends corresponding voltages to the comparators to determine state changes, allowing the system to detect multiple supply voltages using only two comparators, thereby reducing power consumption and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple comparators are used to detect multiple supply voltage ranges, then the voltage detection coverage is improved, but the power consumption increases significantly
Solution Approach 1:
The patent combines multiple voltage detection functions into a single comparator by dynamically changing its reference voltage threshold. The threshold voltage generator produces different reference voltages corresponding to different detection ranges, allowing one comparator to perform the work of multiple comparators. This merging approach maintains full voltage detection coverage while significantly reducing power consumption by eliminating redundant comparator circuits.
Solution Approach 2:
The patent introduces dynamic switching of the comparator's reference voltage threshold based on the current detection state. The threshold voltage generator dynamically adjusts the threshold level according to the detected voltage range, enabling a single comparator to adaptively detect multiple voltage ranges. This dynamic approach replaces the static multiple-comparator architecture, reducing power consumption while maintaining detection versatility.
2Measurement precision
If multiple comparators are used to detect multiple supply voltage ranges, then the detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple detection functions into a single comparator by combining it with a threshold voltage generator. The threshold voltage generator produces multiple reference voltage levels that correspond to different detection thresholds. This combination allows one comparator to replace multiple comparators, reducing device complexity while maintaining the ability to accurately detect multiple voltage ranges through dynamic threshold adjustment.
Solution Approach 2:
The patent makes the comparator universal by enabling it to perform multiple detection functions through dynamic threshold switching. The same comparator circuit is used for detecting all voltage ranges, with its reference voltage changed according to the required detection level. This multi-functional approach reduces the number of components needed while maintaining comprehensive voltage detection capability.
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 solution effectively detects multiple supply voltages with reduced power consumption and fewer comparators, enhancing the overall system performance by minimizing power usage while maintaining accurate voltage detection.
Implementation Method 1
a VDD is divided by resistors R1 and R2 to obtain a voltage VIN
Implementation Method 2
the Schmitt Trigger comparator 103 outputs a high level when the VIN is lower than the VREF, and then the voltage of the output node MRK is at a high level
Data Source
AI summary
An apparatus comprises a supply voltage divider, a state machine, two comparators and a threshold selector. The supply voltage divider divides a VCC into N states SK, and acquires the border voltages VK and VK+1 corresponding to the SK through a resistor divider. The threshold selector acquires a corresponding voltage VK from the supply voltage divider according to the current state SK outputted by the state machine and then sends the acquired VK as VH to a first comparator, and acquires a corresponding voltage VK+1 and sends the acquired VK+1 as VL to a second comparator. The state machine determines whether or not the VH and the VL are matched with the current state SK. If matched, the OSC of the state machine will be turned off, otherwise, the next state Sk+1 or Sk−1 of the SK will be outputted.