External Device Power Control During Low Power Sleep Mode
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Solution Overview
Problem
Current integrated circuit devices in low power modes require the external wake signal source to remain operational, leading to increased system power consumption, as they need to continuously wake up the main logic circuits to monitor external devices, which is wasteful, especially in battery-powered applications where power conservation is critical.
Innovation Solution
Implementing a system that uses existing low power mode timers and a simplified 2-channel PWM function to periodically wake up external devices without activating the main logic circuits, allowing the external devices to power down and wake up independently, with power-up and sample timers managing the wake-up process based on logic or analog output levels, thus reducing overall power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the external wake signal source remains operational to wake up the integrated circuit device from low power mode, then the device can be reliably woken up, but the system power consumption increases
Solution Approach 1:
The patent segments the wake-up function into two independent parts: (1) a low-power timer circuit that operates independently in deep sleep mode to generate wake-up signals, and (2) the main processor that remains in deep sleep mode. This segmentation allows the wake-up function to be performed without activating the power-hungry main processor, thus reducing system power consumption while maintaining reliable wake-up capability.
Solution Approach 2:
The low-power timer circuit is designed to autonomously perform the wake-up function without requiring main processor intervention. The timer independently monitors external devices, generates wake-up signals when conditions are met, and manages the power-up sequence, effectively making the system self-sufficient for wake-up operations and eliminating the need to keep the main processor active.
2Reliability
If the main logic circuits are continuously activated to monitor external devices, then the external devices can be monitored effectively, but the power consumption increases
Solution Approach 1:
The monitoring function is segmented between the low-power timer circuit and the main processor. The timer circuit independently monitors external devices using minimal power, while the main processor remains in deep sleep mode. When the timer detects a wake condition, it autonomously generates a wake-up signal to activate the processor, thus maintaining effective monitoring while minimizing power consumption.
Solution Approach 2:
The low-power timer circuit performs periodic monitoring of external devices at predetermined intervals rather than continuous monitoring. This periodic action is sufficient to detect wake conditions while consuming significantly less power than continuous monitoring by the main processor, achieving a balance between monitoring effectiveness and power conservation.
3Measurement precision
If the external device is kept operational for continuous monitoring, then the monitoring accuracy is improved, but the overall power consumption increases
Solution Approach 1:
The external device is activated periodically by the low-power timer circuit only when monitoring is required, rather than being kept continuously operational. This periodic activation maintains the ability to detect external conditions accurately while minimizing the time the external device consumes power, thus reducing overall system power consumption while preserving monitoring accuracy.
Solution Approach 2:
The low-power timer circuit acts as an intermediary between the external device and the main processor. It briefly activates the external device only when needed for monitoring, processes the information, and then deactivates it. This intermediary approach allows accurate monitoring to be performed on-demand without the continuous power consumption that would result from keeping the external device permanently active.
Data Source
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AI summary
An integrated circuit device controls power up of an external device used for sensing a process variable independently of whether the integrated circuit device is in a low power sleep mode. Once the external device becomes operational the integrated device, even when still in the low power sleep mode, samples the process variable status of the external device. Low power timing circuits operational during the low power sleep mode control the power up of the external device and sampling of the process variable status thereof. After the sample of the process variable status is taken, the integrated circuit device may be brought out of the low power sleep mode to an operational mode when appropriate as determined from the sampled process variable status.