POR/UVLO Circuit with Dynamic Impedance Switching
Solution Overview
Problem
Conventional power-on reset (POR) and under-voltage lockout (UVLO) systems in electronic circuits consume high power due to high impedance, leading to energy inefficiency and reliability issues, particularly under low load conditions.
Innovation Solution
The implementation of a system utilizing two positive feedback loops with transistors, Zener diodes, and resistors to generate power-on reset and under-voltage lockout signals, which reduces power consumption and enhances reliability by ensuring proper functioning across varying voltage thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional POR/UVLO circuits are used with high impedance, then voltage detection and reset functionality is achieved, but power consumption increases significantly
Solution Approach 1:
The patent implements dynamic impedance switching in the POR/UVLO circuit. During normal operation, the circuit maintains high impedance to minimize power consumption. During reset or lockout events, the impedance dynamically switches to low state to ensure reliable voltage detection and signal generation. This dynamic adaptation resolves the contradiction between continuous high reliability and continuous low power consumption.
Solution Approach 2:
The circuit employs periodic monitoring of voltage thresholds with active intervention only when thresholds are violated. The high-impedance state is maintained periodically between detection events, while low-impedance active detection occurs only when needed for reset or lockout conditions. This periodic activation pattern reduces overall power consumption while maintaining detection reliability.
2Use of energy by moving object
If high impedance is used in POR/UVLO circuits, then power consumption is reduced, but reliability and proper functioning at voltage thresholds deteriorates
Solution Approach 1:
The patent incorporates feedback mechanisms where the output of the voltage detection circuit feeds back to control the impedance state of the detection network. When voltage thresholds are approached or violated, the feedback signal triggers a transition to low-impedance state to ensure accurate detection and generate appropriate reset or lockout signals. This feedback-controlled impedance adjustment maintains reliability while minimizing power consumption during normal operation.
Solution Approach 2:
The circuit dynamically changes the impedance parameter based on operating conditions. During normal voltage operation, the impedance is set to high values to reduce power consumption. When voltage thresholds are detected, the impedance parameter changes to low values to ensure reliable signal generation. This parameter adaptation resolves the contradiction between power consumption and detection reliability.
3Ease of operation
If conventional POR/UVLO circuits are used, then basic voltage monitoring is achieved, but system stability under varying load conditions deteriorates
Solution Approach 1:
The patent implements dynamic response characteristics in the POR/UVLO circuit to adapt to varying load conditions. The circuit dynamically adjusts its detection thresholds and response timing based on observed voltage variations and load changes. This dynamic adaptation maintains system stability by preventing false reset or lockout events during transient load variations while ensuring proper response to genuine voltage failures.
Solution Approach 2:
The circuit uses feedback mechanisms to monitor voltage trends and adjust detection sensitivity accordingly. During periods of stable operation, the feedback maintains high detection thresholds to prevent false positives. During transient conditions, the feedback adjusts thresholds and response timing to maintain stability. This feedback-controlled stability management resolves the contradiction between continuous monitoring functionality and system stability under varying conditions.
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 results in lower power consumption and improved reliability for POR/UVLO functions, effectively managing power transitions and preventing system instability under different load conditions.
Implementation Method 1
The system utilizes two positive feedback loops with transistors, Zener diodes, and resistors to generate power-on reset and under-voltage lockout signals
Data Source
AI summary
A system and method for power-on reset and under-voltage lockout schemes. The system includes a first transistor, which includes a first gate, a first terminal, and a second terminal, the second terminal being biased to a predetermined voltage. The system includes a second transistor, which include a second gate, a third terminal, and a fourth terminal, the third terminal being configured to receive an input voltage. The system includes a first resistor that is associated with a first resistance. The first resistor includes a fifth terminal and a sixth terminal, the fifth terminal being configured to receive the input voltage. The system includes a second resistor that is associated with a second resistance. The second resistor includes a seventh terminal and an eighth terminal, the seventh terminal being coupled to the sixth terminal. The system includes a first Zener diode that is associated with a first Zener voltage.