Impedance Matching Circuit With PVT Calibration for Stable I/O Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Impedance mismatching caused by variations in manufacturing processes, supply voltage, and operation temperature (PVT) leads to distorted signals and hindered high-speed data transmission in semiconductor devices.
Innovation Solution
An impedance matching circuit embedded in semiconductor devices, utilizing a PVT calibration circuit with a replica post driver, comparator, and counter to generate calibration codes that adjust the resistance values of post drivers to match external resistors, reducing power consumption and increasing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If impedance matching is not performed, then power consumption is reduced and circuit complexity is lowered, but signal transmission accuracy deteriorates and high-speed data transmission becomes difficult due to impedance mismatching
Solution Approach 1:
The patent changes the resistance values of post drivers dynamically based on PVT conditions through calibration. By adjusting the resistance parameter of post drivers to match external impedances under different process, voltage, and temperature conditions, the system achieves impedance matching without requiring complex continuous adjustment circuits.
Solution Approach 2:
The patent performs preliminary calibration of post driver resistance values before actual signal transmission. The PVT calibration circuit pre-adjusts the impedance parameters based on detected PVT conditions, so that when data transmission occurs, the impedance matching is already established, eliminating the need for complex real-time adjustment mechanisms.
2Measurement precision
If PVT calibration circuit is added to perform impedance matching, then signal transmission accuracy is improved, but power consumption increases due to additional calibration operations
Solution Approach 1:
The patent performs PVT calibration periodically or at specific intervals rather than continuously. The calibration operation is triggered based on detected PVT conditions or at predetermined timing, allowing the system to balance between maintaining accurate impedance matching and reducing power consumption by keeping the calibration circuit inactive during normal operation.
3Stability of the object's composition
If continuous impedance adjustment is performed to maintain matching under PVT variations, then impedance matching accuracy is maintained, but power consumption and circuit complexity increase
Solution Approach 1:
The system performs preliminary PVT calibration to establish appropriate resistance values before actual operation. By pre-configuring the impedance parameters based on detected PVT conditions, the system achieves stable impedance matching without requiring continuous adjustment mechanisms, thereby reducing power consumption while maintaining stability.
Data Source
AI summary
An impedance matching circuit is provided. The impedance matching circuit includes a reference voltage generator configured to generate a reference voltage. A code generator is configured to generate a first calibration code by comparing the reference voltage with a first voltage associated with a first node and a second calibration code by comparing the reference voltage with a second voltage associated with a second node. A first resistance unit is configured to supply the first voltage to the first node in response to the first calibration code to calibrate its resistance to be equal to a reference resistance. A second resistance unit is configured to supply the second voltage to the second node in response to the second calibration code to thereby calibrate its resistance to the reference resistance.