Power-On Reset Circuit With Adaptive Voltage Thresholding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor integrated circuits face power-up malfunctions due to varying power supply voltages, which existing power on reset circuits struggle to address effectively, leading to unreliable reset signal activation and inactivation.
Innovation Solution
A power on reset circuit comprising a current mirror, comparative voltage generator, driver, and ground selecting transistor, which adjusts the voltage level of a detection node based on the power supply voltage to activate or inactivate a reset signal, utilizing resistors and transistors to control the current flow and voltage division, thereby optimizing reset signal timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing power on reset circuits are used, then the circuit can provide reset functionality, but the reset signal activation and inactivation becomes unreliable under varying power supply voltages
Solution Approach 1:
The patent changes the operating parameters of the reset circuit by using a current mirror to generate a current proportional to the power supply voltage, and a comparative voltage generator to create a reference voltage that varies with the power supply voltage. This allows the reset circuit to adapt to different power supply voltage levels while maintaining reliable reset signal activation and inactivation.
Solution Approach 2:
The patent implements a feedback mechanism where the reset signal is controlled based on the comparison between the actual power supply voltage and a predetermined reference voltage. The driver circuit activates or inactivates the reset signal according to this comparison, ensuring reliable operation across varying power supply conditions.
2Reliability
If the reset signal is activated at incorrect voltage levels, then power-up malfunctions occur, but adjusting the activation threshold reduces adaptability to different power supply voltages
Solution Approach 1:
The patent dynamically adjusts the voltage threshold for reset signal activation by generating a comparative voltage that is proportional to the power supply voltage through the current mirror and resistive divider network. This allows the circuit to maintain reliable power-up operation while adapting to different power supply voltage levels.
3Reliability
If complex voltage regulation circuits are added to ensure reliable reset signal, then reliability improves, but device area and circuit complexity increase
Solution Approach 1:
The patent employs a self-service approach where the reset circuit uses the power supply voltage itself to generate the reference voltage through the current mirror and resistive divider. This eliminates the need for external voltage references or complex regulation circuits, maintaining reliability while reducing device area and circuit complexity.
Solution Approach 2:
The current mirror circuit serves multiple functions: it provides current for the comparative voltage generator, establishes the voltage reference, and enables adaptation to different power supply levels. This multi-functionality reduces the need for separate components, thereby reducing overall circuit complexity.
Data Source
AI summary
Embodiments may disclose a power on reset circuit, which includes: a current mirror connected to a power node, the power node receiving a variable power supply voltage, the current mirror being configured to supply a first current to a first line and a second current to a second line; a comparative voltage generator configured to generate a comparative voltage using the first current provided via the first line; a driver connected to the second line, the driver being configured to activate a reset signal in response to a voltage of the second line; and a ground selecting transistor configured to connect the second line and a ground node according to the comparative voltage.