Low Power Oscillator Timing Circuit for Battery Life Extension
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Solution Overview
Problem
Wireless devices, such as medical patches, face significant battery life challenges due to high power consumption in idle states, with only a small percentage of energy used during active states, leading to reduced shelf life and increased size requirements.
Innovation Solution
Implementing a low power oscillator and timing circuit within a wireless device to manage power, activating the main device only when necessary, using a battery pass circuit to conserve energy and extend battery life by minimizing active time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the main device remains continuously powered on to ensure immediate responsiveness, then the device can respond instantly to user inputs or external events, but the battery life is significantly reduced due to continuous power consumption
Solution Approach 1:
The patent implements periodic wake-up cycles where the low power device activates the main device at predetermined intervals. The low power device enters sleep mode between activations, consuming minimal power, while still maintaining the ability to periodically service the main device and respond to events. This periodic operation resolves the contradiction by balancing immediate responsiveness with extended battery life.
2Productivity
If the main device is kept in active state to perform tasks continuously, then productivity is improved, but power consumption increases dramatically
Solution Approach 1:
The patent divides the device into two functional segments: a low power device that remains continuously active for timekeeping and event detection, and a main device that operates intermittently to perform tasks. This segmentation allows the system to maintain productivity through the coordinated operation of both segments while significantly reducing overall power consumption by keeping the high-power main device dormant most of the time.
Solution Approach 2:
The low power device acts as an intermediary between the battery and the main device. It manages power distribution, activating the main device only when tasks need to be executed, and keeping it in sleep mode otherwise. This intermediary role enables the system to maintain task execution capability while optimizing power consumption by controlling when the main device is active.
3Measurement precision
If the device uses a high power oscillator for accurate timekeeping, then timing precision is improved, but battery life is reduced
Solution Approach 1:
The patent applies local quality by implementing two different oscillators with different characteristics in different parts of the system. The low power device uses a low power oscillator optimized for minimal power consumption during continuous operation, while the main device uses a high precision oscillator only when activated. This local differentiation resolves the contradiction by providing accurate timekeeping when needed while maintaining low overall power consumption.
Data Source
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AI summary
In one embodiment, an electronic device comprises an oscillator configured to generate an oscillator signal, and a timing circuit configured to generate a count value based on the oscillator signal, to compare the count value with a first compare value, to determine a first expiry event upon the count value matching the first compare value, and to generate a first wakeup signal in response to the first expiry event. The electronic device also comprises a battery pass circuit configured to receive the first wakeup signal, and to couple a power source to a main device in response to the first wakeup signal to power on the main device. The electronic device further comprises a state sequencing circuit configured to store a state of the main device, and an interface circuit configured to communicate the stored state to the main device.