MOSFET Shunt Voltage Regulator Using Avalanche Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current voltage regulators for RFID applications are too complex, consume high power, and occupy large surface areas, making them unsuitable for optimizing signal strength and protecting internal components from overvoltage.
Innovation Solution
A voltage regulator circuit using a feedback loop with a P-channel MOSFET shunt transistor, which monitors a weak avalanche current to regulate voltage, reducing the size of the shunt transistor and providing dynamic field-dependent compensation to control impedance and protect against overvoltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional voltage regulators (voltage reference, resistive divider, operational amplifier) are used, then voltage regulation is achieved, but device complexity, power consumption, and surface area increase
Solution Approach 1:
The patent extracts and eliminates unnecessary components from conventional voltage regulators. By removing the voltage reference, resistive divider, and operational amplifier, the design achieves voltage regulation through a simplified feedback mechanism that directly controls the shunt transistor gate, dramatically reducing circuit complexity while maintaining regulation functionality
Solution Approach 2:
The patent implements self-service by using the avalanche current inherently generated by the shunt transistor's body diode as the feedback signal. This self-generated current eliminates the need for external voltage references and complex sensing circuits, allowing the system to regulate voltage using its own operational characteristics
2Reliability
If conventional voltage regulators are used, then voltage regulation is achieved, but power consumption increases
Solution Approach 1:
The patent removes power-hungry components such as the operational amplifier and resistive divider from the circuit. The simplified design using only the shunt transistor and feedback connection to the gate significantly reduces static and dynamic power consumption while maintaining effective voltage regulation
Solution Approach 2:
The system uses the naturally occurring avalanche current in the shunt transistor as the feedback mechanism, eliminating the need for additional power-consuming sensing and control circuits. This self-service approach leverages the transistor's inherent properties to achieve regulation with minimal power overhead
3Reliability
If conventional voltage regulators are used, then voltage regulation is achieved, but surface area increases
Solution Approach 1:
The patent extracts and removes multiple discrete components (voltage reference circuit, resistive divider network, operational amplifier) that occupy significant silicon area. The resulting compact design uses minimal transistors and connections, achieving effective voltage regulation in a small footprint suitable for RFID tags
Solution Approach 2:
The patent merges the voltage regulation function directly into the shunt transistor's operation by using its body diode's avalanche current as the feedback signal. This integration eliminates separate regulation circuits and reduces the overall surface area required for the voltage regulation functionality
4Area of stationary object
If shunt transistor size is reduced, then surface area decreases, but robustness against temperature and process variations worsens
Solution Approach 1:
The patent implements a feedback mechanism that monitors the avalanche current through the body diode and adjusts the shunt transistor gate voltage accordingly. This feedback loop compensates for temperature and process variations, allowing the use of smaller transistors without sacrificing robustness, as the feedback dynamically corrects for environmental changes
Solution Approach 2:
The patent exploits the temperature-dependent characteristics of the avalanche current in the body diode. By using this inherently temperature-sensitive current as the feedback signal, the circuit automatically adapts to temperature variations, maintaining regulation accuracy even with reduced transistor sizes that would otherwise be more sensitive to process and temperature changes
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 reduces power consumption, surface area, and enhances robustness against temperature and process variations, maintaining stable voltage and optimizing signal strength in RFID devices.
Implementation Method 1
a relatively weak avalanche current between a body terminal and a drain of a P-channel metal-oxide semiconductor field-effect transistor (MOSFET) shunt transistor
Data Source
AI summary
A voltage regulator is provided. The voltage regulator includes a shunt transistor and a feedback circuit. The shunt transistor has a first current electrode coupled to a first voltage source terminal, a second current electrode coupled to a second voltage source terminal, a control electrode coupled to receive a reference voltage, and a body electrode. The feedback circuit has an input terminal coupled to the body electrode of the shunt transistor, and an output terminal coupled to the control electrode of the shunt transistor. The voltage regulator is suitable for use in a passive RFID device to protect the device from over-voltage damage. In another embodiment, a method for regulating a voltage is provided.