Delay Circuit Feedback Compensation for PVT Timing Stability
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Solution Overview
Problem
Existing delay circuits in semiconductor elements, such as those used in Dynamic Random Access Memory (DRAM), face significant variations in delay time due to changes in power supply voltage, operating temperature, and manufacturing process, leading to accuracy issues.
Innovation Solution
A control circuit and delay circuit design incorporating a control unit and feedback unit that adjust voltage to compensate for variations in power supply voltage, operating temperature, and manufacturing process, using a potential generating circuit to stabilize current through transistors, thereby minimizing delay time variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional delay circuits are used without compensation mechanisms, then the circuit structure remains simple, but the delay time varies significantly with power supply voltage, operating temperature, and manufacturing process
Solution Approach 1:
The patent implements feedback control by detecting the actual delay time of the delay circuit and comparing it with a target delay time. Based on the comparison result, the control circuit adjusts the compensation voltage applied to the substrate terminals of transistors in the delay circuit, thereby correcting the delay time to match the target value. This closed-loop feedback mechanism effectively reduces delay time variations caused by power supply voltage, temperature, and manufacturing process fluctuations.
Solution Approach 2:
The patent changes the substrate voltage parameter of transistors in the delay circuit to compensate for delay time variations. By adjusting the compensation voltage applied to the substrate terminals based on the detected delay time error, the transistor threshold voltages are modified, which in turn adjusts the delay time of the delay circuit to achieve accurate timing control despite variations in operating conditions.
2Measurement precision
If delay time accuracy is improved through compensation mechanisms, then the delay time remains stable across different operating conditions, but the control circuit complexity increases
Solution Approach 1:
The patent implements feedback control by detecting the actual delay time of the delay circuit and comparing it with a target delay time. Based on the comparison result, the control circuit adjusts the compensation voltage applied to the substrate terminals of transistors in the delay circuit, thereby correcting the delay time to match the target value. This closed-loop feedback mechanism effectively reduces delay time variations caused by power supply voltage, temperature, and manufacturing process fluctuations.
Solution Approach 2:
The patent employs self-calibration by using the delay circuit itself as the calibration object. The delay time detection unit measures the actual delay time of the delay circuit, and the control circuit uses this information to automatically adjust the compensation voltage, enabling the system to self-correct without requiring external calibration equipment or manual intervention.
3Adaptability or versatility
If the delay circuit operates under varying power supply voltage and temperature, then the circuit remains adaptable to different conditions, but the delay time variation increases
Solution Approach 1:
The patent implements feedback control by detecting the actual delay time of the delay circuit and comparing it with a target delay time. Based on the comparison result, the control circuit adjusts the compensation voltage applied to the substrate terminals of transistors in the delay circuit, thereby correcting the delay time to match the target value. This closed-loop feedback mechanism effectively reduces delay time variations caused by power supply voltage, temperature, and manufacturing process fluctuations.
Solution Approach 2:
The patent changes the substrate voltage parameter of transistors in the delay circuit to compensate for delay time variations. By adjusting the compensation voltage applied to the substrate terminals based on the detected delay time error, the transistor threshold voltages are modified, which in turn adjusts the delay time of the delay circuit to achieve accurate timing control despite variations in operating conditions.
Data Source
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AI summary
A control circuit and a delay circuit are provided. The control circuit includes a control unit and a feedback unit. The feedback unit is configured to output a feedback signal according to a voltage of the control unit and a reference voltage; a first terminal of the feedback unit is connected to a first terminal of the control unit, a second terminal of the feedback unit serves as an input terminal of the reference voltage, and an output terminal of the feedback unit is connected to a second terminal of the control unit. The control unit is configured to adjust a voltage of the second terminal of the control unit according to the feedback signal, so as to allow a current variation of the control unit with a first parameter to be within a first range; the first parameter includes at least one of a manufacturing process of the control circuit, a power supply voltage of the control circuit, and an operating temperature of the control circuit; a third terminal of the control unit is connected to a first power supply terminal, and a fourth terminal of the control unit is connected to a negative power supply terminal, or, the third terminal of the control unit is connected to a second power supply terminal, and the fourth terminal of the control unit is connected to a ground terminal. Thus, the second terminal of the control unit can output a voltage that varies with any of a power supply voltage, an operating temperature, and a manufacturing process.