Voltage Reference Circuit Using Gate-to-Source Voltage Difference
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Solution Overview
Problem
Conventional voltage reference generation circuits face challenges in achieving low temperature coefficient, high power supply rejection ratio (PSRR), low fabrication cost, and minimizing body effect, which limits their application and efficiency, especially in wideband applications.
Innovation Solution
A voltage reference generation circuit is designed with a reduced number of current paths, utilizing a combination of gate-to-source voltages and feedback circuits with common-source configurations, incorporating transistors to generate a voltage reference with improved temperature stability and PSRR, while reducing the need for resistive elements and minimizing body effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional voltage reference generation circuit uses multiple current paths and resistors for temperature compensation, then the temperature coefficient is reduced, but the power supply rejection ratio deteriorates and energy consumption increases
Solution Approach 1:
The patent extracts and eliminates the resistor elements from the voltage reference generation circuit, replacing them with a transistor-based structure. This removal of resistors directly addresses the PSRR deterioration problem while maintaining temperature compensation through the transistor's gate-to-source voltage characteristics
Solution Approach 2:
The patent substitutes the resistor-based temperature compensation mechanism with a transistor-based mechanism. The MOSFET's gate-to-source voltage (Vgs) is used to provide temperature compensation, replacing the traditional resistor network and thereby improving PSRR and reducing energy consumption
2Reliability
If a pre-regulator circuit is added to enhance PSRR, then power supply disturbance is suppressed, but the circuit complexity increases and wideband application is limited
Solution Approach 1:
The patent merges the voltage reference generation function with the voltage regulation function into a single integrated circuit structure. The MOSFET operates simultaneously to generate the voltage reference and provide regulation, eliminating the need for separate pre-regulator circuits and reducing overall circuit complexity
Solution Approach 2:
The MOSFET in the patent serves multiple functions: it generates the voltage reference through its gate-to-source voltage, provides temperature compensation, and delivers wideband voltage regulation. This multi-functionality replaces what would traditionally require multiple separate circuits
3Temperature
If resistors are used in the voltage reference generation circuit, then temperature compensation is achieved, but the body effect increases and fabrication cost rises
Solution Approach 1:
The patent extracts and removes all resistor elements from the voltage reference generation circuit, replacing them with MOSFET-based structures. This elimination of resistors directly reduces the body effect while maintaining temperature compensation through the transistor's Vgs characteristics
Solution Approach 2:
The patent changes the fundamental parameter used for temperature compensation from resistor values to MOSFET gate-to-source voltage. This parameter change enables temperature compensation without introducing the body effect associated with resistors in MOSFET circuits
Data Source
AI summary
A voltage reference generation circuit includes a current supply circuit and a core circuit. The current supply circuit is arranged to provide a plurality of currents. The core circuit is coupled to the current supply circuit, and arranged to receive the currents and accordingly generate a voltage reference. The core circuit includes a first transistor, a second transistor and a third transistor, wherein the first transistor and the third transistor generate a first gate-to-source voltage and a third gate-to-source voltage, respectively, according to a first current of the received currents; the second transistor generates a second gate-to-source voltage according to a second current of the received currents; and the voltage reference is generated according to the first gate-to-source voltage, the second gate-to-source voltage and the third gate-to-source voltage.