Hybrid CTLE-DFE Receiver Circuit for High-Speed Serial Decoding
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Solution Overview
Problem
Semiconductor integrated circuit devices face challenges in accurately decoding high-speed serial data due to signal loss and inter-symbol interference caused by transmission channel characteristics, which existing equalization methods struggle to effectively compensate for.
Innovation Solution
The implementation of a semiconductor integrated circuit device with a combination of Continuous Time Linear Equalizer (CTLE) and Decision Feedback Equalizer (DFE) circuits, along with a sampler circuit, which compensates for signal loss by amplifying high-frequency bands and reducing noise through adaptive equalization and decision feedback processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single equalization method (CTLE or DFE) is used, then the circuit complexity is low, but the compensation effectiveness for signal loss and inter-symbol interference is insufficient
Solution Approach 1:
The patent combines CTLE (Continuous Time Linear Equalizer) and DFE (Decision Feedback Equalizer) circuits into a hybrid equalization system. The CTLE compensates for frequency-dependent losses in the transmission channel, while the DFE addresses inter-symbol interference through feedback mechanisms. This merging of two different equalization approaches enables comprehensive signal recovery that neither method could achieve alone, resolving the contradiction between compensation effectiveness and circuit complexity.
Solution Approach 2:
The equalization function is segmented into two distinct stages: first, the CTLE performs linear equalization to compensate for channel loss and shape the signal spectrum; second, the DFE performs non-linear equalization to eliminate inter-symbol interference caused by reflections and multipath effects. This segmentation allows each circuit to specialize in addressing specific types of signal degradation, achieving superior overall performance while maintaining modular circuit architecture.
2Speed
If the processing speed is increased to meet high-speed serial data transmission, then the data transmission speed improves, but the signal loss and inter-symbol interference become more severe
Solution Approach 1:
The DFE component implements a feedback mechanism where previously decoded symbols are used to predict and subtract their interference contribution from the current symbol decision. This feedback approach dynamically compensates for inter-symbol interference that worsens with increasing transmission speed, enabling reliable high-speed data transmission by continuously adapting to the degraded signal conditions.
Solution Approach 2:
The hybrid equalization system adjusts its processing parameters to match the transmission speed requirements. The CTLE provides continuous time-domain equalization that scales with bandwidth, while the DFE's feedback taps are configured to address interference patterns specific to the current data rate. This parameter adaptability allows the system to maintain signal quality across varying transmission speeds.
Data Source
AI summary
According to one embodiment, a semiconductor integrated circuit device comprises first and second transistors having control terminals receiving an input signal and an inversion signal of the input signal, third and fourth transistors having control terminals receiving the input signal and the inversion signal, first and second inverters in which outputs are connected to inputs of other converters, and a fifth transistor connected to the first to fourth transistors. The third and fourth transistors are connected to outputs of the second and the first inverters. Clock signal is supplied to the fifth transistor.