Multi-Phase Driver Topology for Low Power Data Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed interfaces in electronic devices face limitations due to clock skew and interference, particularly in multi-phase systems where power consumption and real estate on circuit boards are significant concerns.
Innovation Solution
A method and apparatus for data transfer using a multi-phase encoding scheme where data is mapped to a sequence of symbols and encoded into three signals, each in different phases, with specific voltage levels being output by drivers to manage signal transmission across multiple terminals, reducing the number of active drivers and thus power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional high-speed interfaces are used to achieve high data transfer rates, then bandwidth is improved, but power consumption and circuit board area increase
Solution Approach 1:
The patent implements periodic action through multi-phase encoding where data is transmitted using sequential phase transitions (e.g., 6-phase encoding with states 0-5). Each phase represents a specific voltage combination across multiple wires, and the encoder transitions between phases periodically to convey data. This periodic phase-based transmission achieves high data rates while keeping drivers inactive during phase transitions, reducing average power consumption compared to continuous high-speed serial interfaces.
Solution Approach 2:
The patent applies segmentation by dividing the data transmission into multiple parallel wires (e.g., 3 wires for 6-phase encoding) rather than using a single high-speed channel. Each wire carries a segmented portion of the signal, and the combination of wire states represents the encoded data. This segmentation allows the system to achieve high bandwidth through parallelism while using lower-power drivers on each individual wire, and enables selective activation of drivers based on the current phase state.
2Reliability
If more drivers are used to increase signal strength and reduce skew, then signal integrity is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent implements dynamics by making the driver activation state change dynamically based on the current phase. In the 6-phase encoding scheme, only specific drivers are activated during specific phases. For example, during phase transitions, only the drivers corresponding to the new phase state are activated, while others are deactivated. This dynamic driver management maintains signal integrity by providing strong drive strength when needed while reducing complexity and power consumption by keeping unnecessary drivers inactive.
Solution Approach 2:
The patent applies universality through multi-phase encoding where the same set of wires and drivers serves multiple functions. The same 3 wires used for data transmission also carry phase information, and the same drivers used for active phases also serve as reference during inactive phases. This multi-functionality reduces the need for dedicated drivers for each function, thereby reducing overall device complexity while maintaining signal integrity through the phased approach.
3Reliability
If differential interfaces are used to provide common-mode rejection, then signal reliability is improved, but power consumption and real estate increase
Solution Approach 1:
The patent applies dimensionality change by transitioning from traditional 2-dimensional differential pairs (one signal wire, one reference wire) to a 3-dimensional multi-phase encoding scheme using 3 wires with 6 possible phase states. Each wire can be in one of 6 phases, creating a higher-dimensional signal space. This dimensional expansion allows the system to encode more information per symbol (achieve higher bandwidth) while using fewer physical wire pairs, thereby reducing circuit board area while maintaining reliability through the inherent error detection capabilities of the phased encoding scheme.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
System, methods and apparatus are described that facilitate transmission of data, particularly between two devices within electronic equipment. Transmission lines are selectively terminated in an N-phase polarity encoded transmitter when the transmission lines would otherwise be undriven. Data is mapped to a sequence of symbols to be transmitted on a plurality of wires. The sequence of symbols is encoded in three signals. A first terminal of a plurality of terminals may be driven such that transistors are activated to couple the first terminal to first and second voltage levels. The first terminal may further be driven such that a dedicated transistor is activated to couple the first terminal to an intermediate voltage level. The dedicated transistor is activated based on a voltage level for driving a second terminal of the three terminals and a voltage level for driving a third terminal of the three terminals.