Power Switch OFF Indication for Break-Before-Make Coordination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power management integrated circuits (ICs) face challenges in ensuring reliable break-before-make operation without complex circuitry to prevent reverse currents and power dissipation, particularly in high-reliability systems with multiple power supplies.
Innovation Solution
Incorporating a decision circuit in each power switch that generates an OFF signal indicating when the power device is fully off, along with enable inputs and optional coordinator circuits, allows for coordinated break-before-make operation using simple logic, eliminating the need for additional circuitry to sense reverse currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple power supplies are connected to the same output node without coordination, then power redundancy is achieved, but reverse currents flow between supplies causing power dissipation and potential damage
Solution Approach 1:
The patent introduces coordinator circuits as intermediary components that mediate between multiple power switches. These coordinators receive status information from each switch and generate enable signals that prevent simultaneous conduction, thereby eliminating reverse current paths while maintaining power redundancy capability
Solution Approach 2:
The patent implements feedback mechanisms where each power switch reports its conduction status to coordinator circuits. The coordinators use this feedback information to dynamically control the enable signals, ensuring that switches are enabled only when safe to conduct, thus preventing reverse current flow
2Reliability
If additional circuitry is added to sense reverse currents and prevent break-before-make failures, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent enables power switches to self-report their conduction status through status signals generated by the switches themselves. This self-service approach eliminates the need for external monitoring circuitry, as the switches provide their own status information to the coordinators for safe sequencing control
Solution Approach 2:
The patent combines the status sensing and coordination functions into integrated coordinator circuits that work closely with the power switches. By merging these functions and using shared signaling infrastructure, the patent reduces overall system complexity compared to having separate sensing and control circuits
3Reliability
If additional circuitry is added to ensure break-before-make operation, then reverse current protection is improved, but power consumption increases
Solution Approach 1:
The patent uses feedback-based coordination where enable signals are generated dynamically based on real-time status information from power switches. This approach ensures protection against reverse currents while minimizing power consumption by enabling switches only when necessary and safe, rather than using continuous monitoring or always-on protection circuitry
Data Source
AI summary
A power switch includes a power device connecting a supply input to an output, and a power switch controller comprising a gate control circuit that turns the power device on and off in response to a command signal and a decision circuit that produces an OFF signal indicating when the power device is fully off. The power device may be integrated or separate from the power switch controller. The gate control circuit may accept one or more enable signals that must be active to turn on the power device, so that OFF signals and enable inputs of multiple power switches can be interconnected to facilitate break-before-make operation using minimal additional circuitry. Coordinated systems of power switches connecting one or more power supplies to one or more loads and methods of coordinating systems of power switches having OFF indication are also provided.