Charge-Sharing Memory Thermometer for Low-Noise Temperature Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Memory devices face performance penalties due to the need for thermometers to determine and provide temperature values, which can be inaccurate during noisy operations, affecting the reliability of performance-enhancing techniques.
Innovation Solution
A multi-sampled, charge-sharing thermometer that averages temperature conversions over thousands of phases to reduce noise and systematically eliminate errors, using a diode with a threshold voltage that changes with temperature, coupled with an analog-to-digital converter and counters to generate accurate digital codes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the thermometer provides temperature values continuously in the background, then the temperature information is always current and available, but conversion errors occur during noisy phases of operation
Solution Approach 1:
The thermometer operates in periodic cycles, alternating between conversion phases and idle phases. During conversion phases, temperature conversions are performed; during idle phases, the system remains quiet to avoid noise. This periodic operation allows the system to provide continuous temperature information while avoiding conversion errors during noisy periods.
Solution Approach 2:
The system performs multiple preliminary temperature conversions and stores them in a buffer before providing the final temperature value. By accumulating multiple conversion results in advance and only providing values when the buffer contains sufficient data, the system ensures accurate readings while maintaining continuous availability.
2Reliability
If the thermometer waits for a controller request to provide temperature values, then conversion errors during noisy phases are avoided, but performance is degraded due to waiting time
Solution Approach 1:
The thermometer proactively performs multiple temperature conversions in advance and stores them in a buffer, so that when a controller requests temperature information, immediately accurate values are available without waiting for new conversions to complete.
Solution Approach 2:
The thermometer continuously performs temperature conversions during non-noisy phases and maintains a buffer of ready-to-use temperature values, ensuring that the useful action of providing temperature information continues without interruption or waiting time.
3Measurement precision
If multiple temperature conversions are performed and averaged, then noise is reduced and accuracy is improved, but the complexity of the thermometer increases
Solution Approach 1:
The temperature measurement process is segmented into multiple independent conversion phases, each producing a separate temperature value. These individual conversions are then averaged to reduce noise. The segmentation allows complex averaging to be achieved through simple, repeated basic operations.
Solution Approach 2:
The system changes the parameter of conversion duration and repetition count to optimize the balance between accuracy and complexity. By performing a specific number of conversions (e.g., 16 or 32) and averaging them, the system achieves noise reduction with manageable complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables continuous and accurate temperature value generation, reducing noise and ensuring accurate readings, thereby enhancing memory device performance by providing up-to-date and reliable temperature information.
Implementation Method 1
a diode with a threshold voltage that changes with temperature
Implementation Method 2
pulses that cause the first capacitor to connect to the second capacitor and equalize charge between the first capacitor and the second capacitor
Data Source
AI summary
A memory device includes an array of memory cells, a diode having a threshold voltage that changes with temperature, an analog-to-digital converter (ADC), and a pulse generator. The ADC includes a voltage comparator having a positive terminal coupled with the diode. The ADC further includes a first capacitor coupled between a negative terminal of the voltage comparator and ground, and a second capacitor selectively coupled between the first capacitor and a voltage reference node. The second capacitor has a smaller capacitance than that of the first capacitor. The pulse generator is coupled with the ADC and generates pulses. The pulses cause the first capacitor to connect to the second capacitor and equalize charge between the first capacitor and the second capacitor. An inverted signal of the pulses causes the second capacitor to be coupled with the voltage reference node to pre-charge the first capacitor.