Resistor-less Voltage Reference Circuit Using Pseudo Resistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voltage reference circuits in microchips rely on resistors, which are expensive, physically large, and prone to accuracy issues due to resistor matching problems in CMOS technologies, leading to increased power consumption and circuit size.
Innovation Solution
A resistor-less voltage reference circuit using pseudo resistors made of transistors, with a PTAT voltage generator and a CTAT voltage generator, which produce temperature-independent reference voltages by summing PTAT and CTAT voltages, reducing power consumption and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If conventional resistors are used in voltage reference circuits, then the circuit can generate reference voltage, but the circuit size increases and power consumption increases
Solution Approach 1:
The patent extracts and removes the resistor component from the voltage reference circuit, replacing it with a resistor-less design that uses only transistors and capacitors. This elimination of the resistor directly reduces both circuit area and power consumption while maintaining the voltage reference functionality through an alternative mechanism involving transistor-based current mirrors and capacitive voltage division.
Solution Approach 2:
The patent substitutes the physical resistor component with an electronic equivalent implemented through transistor circuits. The resistor's function of establishing voltage relationships is replaced by transistor-based current control and capacitive voltage division, eliminating the need for physical resistive elements and their associated area and power costs.
2Manufacturing precision
If conventional resistors are used in voltage reference circuits, then the circuit can generate reference voltage, but manufacturing accuracy decreases due to resistor matching problems
Solution Approach 1:
The patent removes resistors from the circuit entirely, eliminating the source of resistor matching errors. By replacing resistive elements with transistor and capacitor-based circuits, the design avoids the fundamental manufacturing variability inherent in resistor fabrication, thereby improving reference voltage accuracy without sacrificing functionality.
Solution Approach 2:
The patent changes the fundamental parameters used to establish voltage relationships in the circuit. Instead of relying on resistive voltage division subject to manufacturing tolerances, the design uses transistor current ratios and capacitive division, where the critical parameters (transistor geometry ratios, capacitor ratios) can be controlled with higher precision during fabrication.
3Device complexity
If resistors are used in voltage reference circuits, then the circuit can operate, but the overall circuit complexity increases
Solution Approach 1:
The patent extracts and removes the resistor component from the voltage reference circuit, simplifying the overall circuit architecture. This elimination reduces the number of different component types that must be manufactured and assembled, thereby reducing circuit complexity and easing the manufacturing process while maintaining essential functionality through alternative electronic components.
Data Source
AI summary
A method for generating a reference voltage includes generating a proportional-to-absolute temperature (PTAT) voltage across a first pseudo resistor. The first pseudo resistor includes a transistor. The method also includes converting the PTAT voltage to a current based on a resistance of the first pseudo resistor. The method also includes mirroring the current using a current mirror circuit and converting the mirrored current to a converted PTAT voltage using a second pseudo resistor. The second pseudo resistor includes a transistor. The first pseudo resistor and the second pseudo resistor include equal transistor types. The method also includes generating a complementary-to-absolute temperature (CTAT) voltage, and summing the converted PTAT voltage and the CTAT voltage to produce the reference voltage. The resulting reference voltage is temperature independent.