USB Type-C Connector Slew Rate Control Circuit
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Solution Overview
Problem
USB Type-C connectors face issues with voltage ringing, reduced power efficiency, and false triggering during the transmission of Bi-phase Mark Coding (BMC) encoded data signals across the configuration channel (CC) line, particularly due to uncontrolled slew rates and mismatched rise and fall times, which can lead to electromagnetic interference and power loss.
Innovation Solution
Incorporating additional circuitry within the USB Type-C connectors to control the slew rate of BMC encoded data signals, including a multiplexer, amplifier, and controller, which senses the CC line voltage, equalizes the output node voltage, and connects the transmitter circuit to the CC line after a programmable delay to ensure controlled transitions that meet the specified rise and fall times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If BMC encoded data signals are transmitted across the CC line without slew rate control, then data transmission can occur, but voltage ringing occurs and power efficiency is reduced
Solution Approach 1:
The patent applies preliminary action by equalizing the output node voltage to match the CC line voltage before connecting the transmitter circuit to the CC line. This pre-conditioning prevents voltage ringing and reduces power loss during BMC encoded data transmission, directly addressing the power efficiency issue without requiring complex real-time control mechanisms
Solution Approach 2:
The patent introduces an intermediary voltage equalization circuit between the transmitter circuit and the CC line. This intermediary component (including switches and voltage equalization circuitry) mediates the connection by preparing the voltage levels beforehand, preventing harmful voltage transitions and reducing power loss during data transmission
2Reliability
If the transmitter circuit connects directly to the CC line, then data transmission is immediate, but voltage ringing and electromagnetic interference occur
Solution Approach 1:
The patent performs preliminary voltage equalization before the actual data transmission begins. By pre-matching the output node voltage to the CC line voltage through controlled switching and equalization circuits, the system eliminates voltage ringing and EMI issues that would compromise signal reliability, while the programmable delay ensures minimal transmission latency
Solution Approach 2:
The patent applies preliminary anti-action by preemptively counteracting potential voltage conflicts before they occur. The voltage equalization circuit pre-nulls any voltage differences between the transmitter output and CC line, preventing voltage ringing and electromagnetic interference before they can affect signal transmission reliability
3Reliability
If rise and fall times are not matched, then circuit design is simpler, but false triggering of receivers occurs
Solution Approach 1:
The patent changes the temporal parameters of signal transitions by controlling rise and fall times to be substantially equal through symmetrical switching sequences. This parameter matching prevents false triggering of receivers during BMC encoded data transmission, while the use of coordinated switch pairs (first/second switches and third/fourth switches) maintains circuit design feasibility
Data Source
AI summary
A system, USB Type-C connector and method are provided herein to transmit encoded data across a USB cable from a transmitter circuit included within a transmitting port of a USB Type-C connector. The method described herein may generally include detecting a voltage generated at a configuration channel (CC) pin of a transmitting port of a USB Type-C connector, setting a voltage at an output node of the transmitter circuit equal to the voltage detected at the CC pin before the output node of the transmitter circuit is connected to the CC pin, subsequently connecting the output node of the transmitter circuit to the CC pin, and transmitting the encoded data from the transmitter circuit through the CC pin to the USB cable.