Low Power Reference Circuit With Duty-Cycled Calibration
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Solution Overview
Problem
Conventional integrated reference modules in electronic devices consume excessive power, leading to battery depletion and environmental concerns, as they maintain always-on power consumption, which is not energy efficient and does not account for temperature and voltage fluctuations.
Innovation Solution
A low power reference device comprising precision, low power, calibration, and output modules, along with sequencers, that generates stable reference signals by approximating precise signals using a transconductance cell and duty-cycling non-vital components during a power-save mode to reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional integrated reference module employs a single circuit to generate a precise reference voltage or current that is always on, then the reference signal stability is improved, but the power consumption increases
Solution Approach 1:
The reference module is divided into multiple circuits: a first circuit generating a first reference signal and a second circuit generating a second reference signal. These circuits can be selectively activated based on operational modes, allowing the system to use only the necessary circuit for the current task, thereby reducing power consumption while maintaining reference signal stability when needed.
Solution Approach 2:
The system implements periodic calibration by enabling the first circuit at predetermined intervals to calibrate the second circuit. During normal operation, the lower-power second circuit remains active while the first circuit is periodically activated to ensure accuracy. This periodic action maintains reference signal stability without requiring the high-power first circuit to run continuously.
2Measurement precision
If the reference module is always on to provide stable reference signals, then the reference signal accuracy is improved, but the battery life decreases
Solution Approach 1:
The reference module implements dynamic operation by switching between different circuits based on operational modes. A control circuit determines whether to activate the first high-precision circuit or the second low-power circuit based on system requirements. This dynamic adaptation allows the system to maintain reference signal accuracy when precision is needed while extending battery life during normal operation by using the lower-power second circuit.
Solution Approach 2:
The system changes operational parameters by switching between different reference signal generation modes. The control circuit adjusts which circuit is active based on precision requirements, effectively changing the power consumption parameter while maintaining acceptable reference signal accuracy. This parameter change allows the system to optimize between accuracy and battery life based on real-time needs.
3Loss of energy
If non-vital modules are disengaged to reduce power consumption, then the power saving is improved, but the system complexity increases
Solution Approach 1:
The control circuit serves multiple functions: it monitors system operation, determines operational modes, controls the switching between first and second circuits, and manages calibration timing. By making the control circuit multi-functional, the system achieves power savings through selective circuit disengagement without proportionally increasing system complexity, as the same control structure handles multiple tasks.
Solution Approach 2:
The system implements autonomous mode switching and calibration management through the control circuit, which automatically determines when to activate the first circuit for calibration without requiring external intervention. This self-service capability reduces the need for additional control logic and external management, thereby limiting the increase in system complexity while achieving significant power savings.
Data Source
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AI summary
A low power reference device is disclosed. The low power reference device includes a precision reference module, a low power reference module, a calibration module, an output module and one or more sequencers. The precision reference module is configured to output a first reference signal while the low power reference module is configured to output a second reference signal. The calibration module is configured to receive the first and second reference signals and output a correction signal to the low power reference module. The output module is configured to receive the first and second reference signals and output a final reference signal. The one or more sequencers are configured to drive each of the precision reference modules, low power reference module, calibration module and output module according to a predetermined timing sequence.