Resistance Multiplier Circuit for Precise High Resistance in Small Area
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic circuits face challenges in providing large resistance values without occupying excessive silicon area, and existing active resistor solutions struggle to offer specific and controllable resistance values.
Innovation Solution
A resistance multiplier system that includes a reference resistor and an amplifier to control resistance across transistors, allowing for a specific and controllable resistance value by using a reference resistor and a desired multiplication factor, while utilizing transistors with varying area ratios to achieve large resistance values with minimal silicon area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a standard high-ohmic poly resistor is used to provide large resistance values, then the resistance value is achieved, but the silicon area occupied becomes excessively large
Solution Approach 1:
The invention changes the operating parameters of transistors (bias currents, gate voltages) to achieve large resistance values. By controlling the bias current through a reference resistor and using the transistor's output resistance characteristics, the circuit achieves equivalent large resistance without requiring physically large resistor structures, thus reducing silicon area while maintaining the required resistance value.
2Area of stationary object
If an active resistor solution using PMOS transistors is used, then the silicon area is reduced, but the resistance value becomes difficult to control and specify
Solution Approach 1:
The invention introduces feedback mechanisms where the output of one transistor stage feeds into the control of another. The first PMOS transistor's output resistance is controlled by feedback from the second PMOS transistor, which in turn is controlled by the reference resistor. This feedback loop stabilizes and precisely controls the overall resistance value, making it predictable and designable despite using active transistor components.
Solution Approach 2:
The reference resistor serves as an intermediary element that sets the bias current for the transistor circuit. By controlling the reference current through this intermediary resistor, the invention indirectly but precisely controls the resistance characteristics of the active transistor network, enabling specific and controllable resistance values while maintaining small silicon area.
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 resistance multiplier system provides a specific and controllable large resistance value using a fraction of the area required by standard high-ohmic poly resistors, enabling efficient implementation in electronic circuits like low-dropout regulator circuits.
Implementation Method 1
The inverting input of the amplifier is held at a virtual ground by negative feedback from the output of the amplifier to the inverting input
Implementation Method 2
by negative feedback from the output of the amplifier to the inverting input
Implementation Method 3
A first transistor converts the virtual ground to a first controlled resistance value
Implementation Method 4
A second transistor converts the first controlled resistance value to a second controlled resistance value
Data Source
AI summary
This document discusses, among other things, a resistance multiplier configured to provide a more specific and controllable resistance value, the resistance multiplier including an amplifier configured to control a resistance across a first transistor using a received reference resistance value and to control a resistance across a second transistor using the resistance across the first transistor and a relationship between the first and second transistors.