Current Mirror Startup via Segmented Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bias circuits in integrated circuits face significant power consumption and long start-up times due to high impedance sources and parasitic capacitance, which slow down signal transition and circuit rise times, especially in low power designs.
Innovation Solution
The current mirror circuit is split into two parts, with an amplifier monitoring and controlling the first part to quickly charge the second part, using a comparator and RS flip-flop to disconnect and reconnect the parts, reducing impedance and improving charging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a normal capacitor or MOS capacitor is added to filter noise, then noise filtering is improved, but start-up time increases
Solution Approach 1:
The current mirror circuit is divided into two separate parts: a first current mirror with minimal capacitance for fast response, and a second current mirror with the filtering capacitor for noise reduction. This segmentation allows each part to perform its specialized function without compromising the other, resolving the contradiction between noise filtering and fast start-up.
2Use of energy by moving object
If bias current is reduced to achieve low power consumption, then power consumption is improved, but circuit becomes more susceptible to noise
Solution Approach 1:
By segmenting the current mirror into two parts with different characteristics, the system can operate at low bias currents for power efficiency while the dedicated filtering capacitor in the second current mirror compensates for increased noise susceptibility, maintaining signal integrity despite lower operating currents.
3Use of energy by moving object
If current mirror capacitance is charged with high impedance source, then power consumption is reduced, but charging speed decreases
Solution Approach 1:
The first current mirror is designed with minimal capacitance and optimized for fast charging with high impedance sources, while the second current mirror handles the filtering function. This segmentation allows the system to achieve fast charging speeds without requiring excessive current, thus maintaining low power consumption.
Data Source
AI summary
A current mirror circuit comprising an input driver connected to a plurality of output driver circuits through a current mirror network. The current mirror network is separated into two parts, wherein the first part comprises the input driver circuit and the second part comprises capacitive loads including a filter capacitor. A switch separates the two parts where an amplifier senses the first part and controls the second part to track the first part when the current mirror circuit is activated. The low source resistance of the output of the amplifier facilitates a fast charging of the capacitance of the second part of the current mirror network dramatically improving signal delay and transition time.