Passive Equalizer Circuit for High-Speed Serial Signal Distortion
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Solution Overview
Problem
High-speed serial data transmission systems face signal distortion due to the low-pass filtering effect of transmission lines, leading to attenuation of high-frequency components, which existing receiver ICs with active equalization circuits cannot effectively address without high power consumption.
Innovation Solution
A passive equalizer circuit is integrated into a high-speed communication system, utilizing a combination of off-chip and on-chip passive components, including series resistor-capacitor circuits and a shunt resistor-inductor network, to equalize signals and match impedance, reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active equalization circuits are used in receiver ICs, then signal equalization can be achieved, but power consumption increases significantly
Solution Approach 1:
The patent replaces active equalization circuits with passive equalization circuits. Specifically, it uses an off-chip series resistor-inductor network combined with an on-chip shunt resistor network to achieve equalization without requiring active components that consume power. This substitution of active systems with passive systems directly resolves the contradiction between achieving signal equalization and reducing power consumption.
Solution Approach 2:
The equalization circuit is divided into two segments: an off-chip series resistor-inductor network and an on-chip shunt resistor network. This segmentation allows the high-power-consuming active components to be replaced with passive components distributed across different locations, with the series network handling high-frequency boosting externally and the shunt network providing impedance matching internally, thereby achieving equalization with minimal power consumption.
2Use of energy by moving object
If passive equalization circuits are used, then power consumption is reduced, but impedance matching and frequency distortion compensation become more challenging
Solution Approach 1:
The complex impedance matching task is divided between two networks: the off-chip series resistor-inductor network handles high-frequency signal boosting and partial impedance matching, while the on-chip shunt resistor network provides additional impedance matching and equalization. This segmentation of functions simplifies the design of each individual network while achieving the overall complex goal of impedance matching and frequency distortion compensation.
Solution Approach 2:
The off-chip series resistor-inductor network acts as an intermediary between the transmission line and the receiver IC, performing preliminary equalization and impedance transformation. This intermediary network simplifies the requirements for the on-chip shunt resistor network, making the overall impedance matching more manageable and less complex.
3Productivity
If high-speed serial data transmission is implemented, then data transmission rate increases, but signal distortion due to low-pass filtering effect worsens
Solution Approach 1:
The off-chip series resistor-inductor network is designed to pre-compensate for the low-pass filtering effect of the transmission line and package parasitics before the signal enters the receiver IC. By boosting high-frequency components in advance, the circuit counteracts the anticipated signal distortion, thereby maintaining signal quality at high data transmission rates.
Solution Approach 2:
Equalization and impedance matching are performed preliminarily by the passive networks before the signal is processed by the receiver IC. This preliminary action of equalization ensures that the signal arriving at the receiver is already corrected for frequency distortion, enabling reliable high-speed data transmission without requiring complex active equalization within the IC.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The passive equalizer effectively compensates for frequency distortion and impedance mismatch, providing efficient signal equalization with reduced power consumption and improved high-frequency performance, suitable for data rates up to 10 Giga Bits Per Second.
Implementation Method 1
The passive equalizer circuit includes a series resistor-inductor network
Implementation Method 2
The passive equalizer circuit includes a series resistor-inductor network
Implementation Method 3
The shunt circuit is coupled in a parallel configuration (or in shunt) with a first input of the receiver chip
Implementation Method 4
The transmission line behaves similarly to a low-pass filter, which causes more attenuation to a high-frequency component of the electrical signal than to a low-frequency component of the electrical signal
Data Source
AI summary
A passive equalizer circuit incorporated at a front-end of an integrated receiver circuit uses passive components that are distributed between inside and outside of an integrated circuit package. The passive equalizer circuit has off-chip components that are placed on a printed circuit board and on-chip components that are fabricated on a common integrated circuit die as a receiver chip. The on-chip components include one or more variable resistors for adjusting a degree of equalization. The off-chip components include one or more resistors for fine tuning input impedance matching of the integrated receiver circuit.