Voltage Reference Circuit With Feedback for Low-Power PVT Stability
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Solution Overview
Problem
Generating a reference voltage that remains substantially constant despite variations in temperature, power supply, and load is challenging, as existing circuits often require large components and high power usage to compensate for these fluctuations.
Innovation Solution
A circuit portion comprising a self-cascode circuit and a follower circuit with a feedback loop to generate and stabilize an output reference voltage, using a reference resistor and transistors to counteract variations, allowing for compact and low-power operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If physically large components are used to compensate for PVT variations, then reference voltage stability is improved, but device area increases
Solution Approach 1:
The patent changes the operating parameters by using a feedback mechanism that dynamically adjusts the circuit operation to compensate for PVT variations. The feedback loop monitors the reference voltage and adjusts bias currents or component operating points to maintain stability without requiring large physical dimensions, thus resolving the contradiction between stability and area.
Solution Approach 2:
A feedback loop is introduced to detect variations in the reference voltage caused by PVT effects and automatically counteract them by adjusting circuit parameters. This active compensation mechanism achieves high stability with compact components, eliminating the need for large physical sizes and resolving the trade-off between stability and device area.
2Stability of the object's composition
If power usage is increased to improve compensation for PVT variations, then reference voltage stability is improved, but energy consumption increases
Solution Approach 1:
The patent employs dynamic operation where the compensation mechanism adapts its power consumption based on the actual PVT variations encountered. The feedback loop activates compensation only when variations are detected, allowing the circuit to operate at low power during stable conditions while providing high stability when needed, thus resolving the contradiction between stability and power consumption.
Solution Approach 2:
The feedback mechanism efficiently manages power by continuously monitoring reference voltage stability and activating compensation only when PVT variations exceed acceptable thresholds. This on-demand compensation approach maintains high stability while minimizing average power consumption, resolving the trade-off between stability and energy usage.
3Manufacturing precision
If component precision is increased to reduce PVT variations, then manufacturing precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent implements a self-service mechanism where the circuit automatically compensates for its own PVT variations through the feedback loop. Instead of relying on high-precision components manufactured to tight tolerances, the system uses standard components with the feedback mechanism correcting their imperfections, thus reducing manufacturing precision requirements while maintaining overall stability and simplifying the manufacturing process.
Solution Approach 2:
The feedback loop compensates for component imprecision by detecting output variations and adjusting circuit parameters to counteract them. This allows the use of standard-precision components rather than requiring high-precision manufactured parts, reducing both manufacturing complexity and device complexity while maintaining reference voltage stability.
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 maintains a stable reference voltage by compensating for process, voltage, and temperature variations, enabling the use of small resistors and reducing power consumption, suitable for battery-powered devices and integrated circuits.
Implementation Method 1
the follower circuit portion comprises a feedback loop arranged to counteract variations in the second intermediate reference voltage
Data Source
AI summary
A circuit portion for generating an output reference voltage (VZERO, VUPPER, VLOWER) includes a self-cascode circuit portion, a follower circuit portion, and a reference resistor (R1). The self-cascode circuit portion generates a first intermediate reference voltage (VREF1) at a first node based on an input current (Ibias) provided thereto. The follower circuit portion mirrors the input current (Ibias) and generates a second intermediate reference voltage (VREF2) at a second node based on the first intermediate reference voltage (VREF1). The reference resistor (R1) is coupled to the second node. The follower circuit portion comprises includes a feedback loop that counteracts variations in the second intermediate reference voltage (VREF2), and the circuit portion generates the output reference voltage (VZERO, VUPPER, VLOWER) based on a current through the reference resistor (R1).