IC Output Driver Power Supply Noise Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits powered by external supplies are susceptible to noise, which affects signal quality due to unregulated power supply voltages, leading to amplitude and delay variations in output signals.
Innovation Solution
The implementation of a dual-regulator circuit system within the integrated circuit, where a first and second regulated voltage are generated based on external power supply, allowing a third version of the signal to be output referenced between both voltages, reducing noise impact through predriver circuits and level-shifting techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the output stage is powered by the external power supply to deliver signals, then the signal delivery capability is improved, but the signal becomes susceptible to power supply noise causing amplitude and delay variations
Solution Approach 1:
The patent divides the power supply system into multiple independent regulated voltage domains (first regulated voltage and second regulated voltage) that are separate from the noisy external power supply. The output stage is segmented to operate from these clean regulated domains rather than directly from the external supply, isolating the signal path from power noise while maintaining drive capability.
Solution Approach 2:
The patent introduces regulated voltage circuits as intermediary power sources between the external power supply and the output stage. These regulator circuits act as mediators that convert the noisy external supply into clean, stable regulated voltages that power the signal delivery circuits, thereby eliminating direct coupling between noise and signal paths.
2Device complexity
If a single regulated voltage is used to power the output stage, then the circuit complexity is reduced, but the noise rejection capability is insufficient
Solution Approach 1:
The patent segments the power regulation into multiple independent regulated voltage domains (first and second regulated voltages) rather than using a single regulated supply. Each regulated voltage domain independently powers different aspects of the output stage, providing enhanced noise rejection through voltage domain isolation while maintaining manageable circuit complexity through modular regulation architecture.
Data Source
AI summary
A technique reduces effects of power supply noise on a signal output by an integrated circuit output driver circuit powered at least partially by an external power supply. An integrated circuit includes a first circuit that provides a first version of a signal to be output referenced between a first regulated voltage and a first power supply voltage of an external power supply. A second circuit provides a second version of the signal to be output referenced between a second regulated voltage and a second power supply voltage of the external power supply. A third circuit provides a third version of the signal to be output referenced between the first power supply voltage and the second power supply voltage and based on the first and second versions of the signal to be output and power received from the external power supply.