Adjustable FIR Transmitter Driver Allocation for Repeatable Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Achieving accurate and repeatable finite impulse response (FIR) equalization in electronic circuits is challenging due to manufacturing process variations, leading to intersymbol interference and signal quality degradation.
Innovation Solution
A transmitter system with configurable driver legs and an allocation control module that adjusts the allocation of driver legs among data bits based on an equalization ratio to achieve a desired equalization and output impedance, using a serialized delay arrangement and driver circuitry to filter the output signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If FIR equalization is implemented to mitigate intersymbol interference, then signal quality is improved, but manufacturing process variations cause inaccurate and non-repeatable equalization
Solution Approach 1:
The patent implements adjustable driver legs with configurable enablement states, allowing the transmitter to dynamically adjust its output impedance and equalization characteristics. This dynamic configurability compensates for manufacturing variations by enabling the system to adapt to actual channel conditions rather than relying on fixed, pre-determined equalization parameters.
Solution Approach 2:
The system changes physical parameters (driver leg enablement states) to adjust effective output impedance and equalization ratio. By modifying which driver legs are enabled, the system can continuously tune its electrical characteristics to match actual channel conditions, overcoming the limitations of fixed manufacturing parameters.
2Device complexity
If traditional fixed equalization is used, then device complexity is reduced, but intersymbol interference and signal reflections degrade signal quality
Solution Approach 1:
The transmitter is segmented into multiple independent driver legs, each capable of being individually enabled or disabled. This segmentation allows flexible configuration of the output impedance without requiring complex continuous control circuits, achieving adaptive equalization through discrete, manageable units.
Solution Approach 2:
The driver legs serve multiple functions: they provide both the primary drive signal and the equalization function simultaneously. By allocating different subsets of driver legs to different data bits, the system achieves both impedance matching and intersymbol interference mitigation using the same hardware resources.
3Object-affected harmful factors
If driver legs are allocated to match characteristic impedance, then signal reflections are reduced, but equalization accuracy is compromised by process variations
Solution Approach 1:
The system uses feedback from the channel conditions to determine the optimal configuration of driver legs. By monitoring signal quality and adjusting the enablement state of driver legs accordingly, the system can compensate for manufacturing variations and achieve accurate impedance matching in the actual operating environment rather than relying on theoretical design values.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Apparatus and methods are provided for generating output signals representative of bits of serial data. A transmitter (200) includes driver circuitry (206) configured to generate an output signal at an output node and an allocation control module (250) coupled to the driver circuitry. The driver circuitry includes a plurality of driver legs (232, 230, 234, 236) configured to generate the output signal based on a plurality of data bits. The allocation control module is configured to allocate a respective subset of the plurality of driver legs to a respective data bit of a plurality of data bits, wherein the each subset generates a component of the output signal that is influenced by its respective data bit.