PAM Link Co-Calibration for Nonlinear Voltage Level Distortion

The patent implements a feedback mechanism where the receiving device measures voltage offsets at multiple PAM levels, generates distortion information indicating non-uniform distribution, and transmits this information back to the transmitting device. The transmitting device then adjusts its drive strength parameters based on this feedback to minimize distortion, thereby maintaining high data transmission capacity while eliminating the harmful non-linearity effects.

The patent dynamically changes the drive strength parameters of the transmitting device based on measured voltage offset distributions. By adjusting these parameters in response to detected distortion conditions, the system optimizes the voltage levels at each PAM stage to achieve uniform distribution, thus reducing non-linearity distortion while preserving the high-capacity multi-level signaling capability.

The patent implements a self-service calibration mechanism where the receiving device autonomously measures voltage offsets, generates distortion information, and transmits correction data back to the transmitting device without requiring external calibration equipment or manual intervention. This self-calibrating approach improves data recovery accuracy while minimizing the need for additional complex calibration infrastructure.

The patent combines the distortion detection and calibration functions into the existing receiver and transmitter circuits. The distortion detection circuit is integrated within the receiver, and the drive strength adjustment is performed by the existing transmitter control logic, merging multiple functions into unified circuit blocks rather than adding separate standalone calibration systems, thus limiting the increase in overall device complexity.

The patent performs voltage offset measurement and drive strength parameter adjustment during the initialization or training phase of system operation, before normal data transmission begins. This preliminary calibration action establishes the correct voltage levels and drive strengths in advance, ensuring manufacturing precision is achieved without requiring complex calibration procedures during production or deployment.

The patent uses automatic feedback-based calibration where the receiving device measures actual voltage offsets and communicates this information to the transmitting device, which then self-adjusts its drive strength parameters. This closed-loop approach eliminates the need for manual calibration procedures or complex external testing equipment, thereby improving voltage level uniformity while simplifying the manufacturing and deployment process.