Embedded Resistor Calibration for IC Buffer Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional techniques for calibrating buffer circuits in integrated circuit (IC) I/O circuitry face challenges such as increased platform size, complexity, cost, and calibration time due to variations in fabricating process, voltage, and temperature, which affect impedance values and require multiple compensation resistors for different I/O interfaces.
Innovation Solution
A calibration module with a multiplexor circuit and a single compensation resistor embedded in the package substrate, allowing for selective calibration of buffer circuits across different I/O interfaces, reducing parasitic components and noise, and simplifying the calibration process by using a shared resistor for multiple buffer circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple compensation resistors are used for different I/O interfaces, then calibration accuracy is maintained, but device complexity and component count increase
Solution Approach 1:
A single compensation resistor is designed to serve multiple I/O interfaces through a calibration module that can selectively connect the resistor to different buffer circuits. This universal approach allows one resistor to perform the calibration function for multiple interfaces, reducing component count while maintaining calibration accuracy across all interfaces.
Solution Approach 2:
The calibration module merges the calibration resources for multiple I/O interfaces into a single shared compensation resistor. By combining the calibration function into one centralized resource rather than having separate resistors for each interface, the system reduces component count and complexity while preserving calibration precision through selective connection.
2Measurement precision
If multiple compensation resistors are used for different I/O interfaces, then calibration accuracy is maintained, but platform size increases
Solution Approach 1:
The calibration module implements a universal compensation resistor that can be selectively connected to serve multiple I/O interfaces. This single multi-functional resistor replaces what would otherwise require multiple separate resistors, significantly reducing the area occupied by calibration components on the platform while maintaining the ability to accurately calibrate each interface.
Solution Approach 2:
By merging the calibration resources into a single shared compensation resistor that serves multiple interfaces through selective connection, the physical footprint of calibration components is minimized. This consolidation approach reduces platform size while preserving calibration accuracy for all I/O interfaces.
3Manufacturing precision
If conventional calibration techniques are used, then impedance values are calibrated, but calibration time increases
Solution Approach 1:
The calibration module performs preliminary calibration actions by pre-establishing connection paths between the single compensation resistor and multiple buffer circuits through the multiplexor. This allows sequential calibration of multiple interfaces using one resistor without requiring physical reconfiguration, reducing overall calibration time while maintaining impedance calibration precision.
Solution Approach 2:
The calibration module dynamically reconfigures connection paths between the compensation resistor and different buffer circuits during calibration operations. This dynamic switching capability allows the system to quickly move from calibrating one interface to another without manual intervention, significantly reducing total calibration time while maintaining accurate impedance calibration for each interface.
Data Source
AI summary
Some embodiments include apparatus and methods using a package substrate and a die coupled to the package substrate. The package substrate includes conductive contacts, conductive paths coupled to the conductive contacts, and a resistor embedded in the package substrate. The die includes buffer circuits and a calibration module coupled to the buffer circuits and the resistor. The buffer circuits include output nodes coupled to the conductive contacts through the conductive paths. The calibration module is configured to perform a calibration operation to adjust resistances of the buffer circuits based on a value of a voltage at a terminal of the resistor during the calibration operation.