Body-Bias Potential Circuit for Stable Delay Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing delay circuits in semiconductor elements, such as those used in DRAM, face challenges in maintaining precise delay control due to significant variations in delay time (T) with changes in supply voltage, operating temperature, and manufacturing process, affecting precision.
Innovation Solution
A potential generating circuit comprising a first and second transistor, where the potential at the substrate of each transistor varies with supply voltage, operating temperature, or manufacturing process, is used to adjust the current through inverters in the delay circuit, thereby compensating for changes and maintaining a small variation in delay time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional delay circuits are used, then the circuit structure is simple, but the delay time varies greatly with supply voltage, operating temperature, and manufacturing process
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the body bias voltage of transistors in the delay circuit to compensate for variations in delay time caused by supply voltage, temperature, and manufacturing process changes. The body bias voltage is changed as a control parameter to maintain constant delay characteristics across different operating conditions.
Solution Approach 2:
The patent implements feedback mechanisms where the actual delay time is measured and used to adjust the body bias voltage through control circuits. This closed-loop feedback system continuously compensates for delay variations, ensuring precise delay control despite external parameter changes.
2Measurement precision
If body bias compensation is implemented, then delay precision is improved, but the circuit complexity increases
Solution Approach 1:
The patent introduces body bias voltage as an intermediary parameter that mediates between the external operating conditions (supply voltage, temperature) and the delay time. This intermediary body bias mechanism allows indirect control of delay characteristics without directly modifying the main signal path.
Solution Approach 2:
The patent segments the delay circuit into multiple independent transistor stages, each with individually controllable body bias terminals. This segmentation allows separate control and optimization of each stage's delay contribution, enabling precise overall delay control through cumulative adjustment of individual stages.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure provides a potential generating circuit, an inverter, a delay circuit, and a logic gate circuit. The potential generating circuit includes a first transistor and a second transistor. Potential at a substrate of the first transistor varies with a first parameter. The first parameter is any one of a supply voltage, an operating temperature, as well as a manufacturing process of the potential generating circuit. Potential at a substrate of the second transistor varies with the first parameter. A gate of the first transistor is connected to a drain of the first transistor. The substrate of the first transistor serves as a first output of the potential generating circuit. A gate of the second transistor is connected to a drain of the second transistor. The substrate of the second transistor serves as a second output of the potential generating circuit. Thus, the first output and the second output may respectively output a potential varying with any one of the supply voltage, the operating temperature, as well as the manufacturing process.