Dynamic Sleep Mode Power Rail Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Battery-powered devices shut down prematurely due to battery voltage dropping below software cutoff thresholds, leading to unnecessary battery discharge and reduced operating times, as existing power management techniques fail to effectively utilize remaining charge during sleep modes.
Innovation Solution
Implementing a dynamic sleep mode where power rails are managed based on a dynamic sleep threshold voltage, with power regulators shutting down or maintaining voltage depending on battery voltage levels, and controlling voltage stepping rates to minimize inrush current during mode transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If power rails are collapsed during sleep mode to reduce leakage current, then battery life is extended, but inrush current during wake transitions can pull battery voltage below shutdown threshold
Solution Approach 1:
The patent applies preliminary action by pre-charging the power rail to an intermediate voltage level before fully activating it during wake transitions. This gradual voltage ramping prevents the inrush current that would otherwise occur when switching from a collapsed state, thereby avoiding unintended shutdowns while maintaining the battery life benefits of rail collapsing during sleep mode.
Solution Approach 2:
The patent implements dynamics by making the power rail state adaptive rather than static. The system dynamically transitions between collapsed and active states based on operational needs, and during wake transitions, it uses a two-stage activation process that adjusts the voltage ramping rate according to battery conditions, optimizing both battery life and shutdown reliability.
2Speed
If power rails are sourced during sleep mode to maintain voltage, then device can wake faster, but leakage current unnecessarily discharges the battery
Solution Approach 1:
The patent applies partial action by maintaining only the essential power rails in an active state during sleep mode rather than all rails. Critical subsystems that need to respond quickly to wake events keep their rails sourced, while non-critical rails are collapsed. This selective approach enables fast wake functionality while minimizing leakage current and battery discharge.
3Duration of action of moving object
If software cutoff threshold is set low to maximize battery utilization, then operating time is extended, but device may malfunction from low voltage
Solution Approach 1:
The patent introduces an intermediary mechanism in the form of a voltage ramping controller that mediates between the battery's low voltage state and the device's operational requirements. During wake transitions from sleep mode, this intermediary controls the rate of voltage increase on power rails, ensuring that voltage reaches safe operational levels gradually rather than causing immediate malfunction from sudden low-voltage conditions, thereby enabling extended operating time with maintained reliability.
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A power management technique is provided that operates with regard to a dynamic sleep threshold voltage. If a device's battery voltage is greater than the dynamic sleep threshold voltage, a voltage rail for the device is collapsed during a sleep mode for the device. Conversely, if the battery voltage is less than the dynamic sleep threshold voltage, the voltage rail is sourced during the sleep mode for the device.