USB-C Power Interface Dynamic Overvoltage Protection

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Solution Overview

Problem

Existing power supply interfaces connected via USB-C type connectors and cables, particularly those using USB-PD technology, face challenges in efficiently managing and protecting against overvoltages, which can lead to malfunctions or damage to electronic devices.

Innovation Solution

A power supply interface comprising a switch, voltage divider bridge, comparator, digital-to-analog converter, and control circuits that negotiate a setpoint value and adapt the power supply to prevent overvoltages by comparing the received voltage to both a fixed and variable threshold, ensuring safe and efficient power delivery to the load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed threshold is used for overvoltage detection, then the detection is simple and reliable, but it cannot adapt to different power supply scenarios and negotiated setpoint values

Engineering Contradiction:
Improveadaptability to different power supply scenariosVSAvoidcomplexity of threshold management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic threshold adjustment by introducing a variable threshold that adapts based on the negotiated setpoint value from the power supply interface. The threshold is no longer fixed but changes dynamically according to the actual power delivery agreement, allowing the system to adapt to different power supply scenarios while maintaining protection functionality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the threshold parameter from a fixed value to a variable value that depends on the negotiated setpoint. By making the threshold parameter adjustable and scenario-dependent, the system achieves versatility across different power supply conditions without requiring multiple fixed threshold circuits.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If only a fixed threshold is used for overvoltage detection, then the device structure is simple, but it may fail to protect against overvoltages in USB-PD technology where power delivery is negotiated

Engineering Contradiction:
Improveprotection effectiveness against overvoltagesVSAvoidcomplexity of voltage detection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a dynamic threshold mechanism that adjusts the overvoltage detection level based on the negotiated setpoint value. This dynamic approach ensures reliable protection against overvoltages in USB-PD technology where power delivery is negotiated, while avoiding the need for overly complex detection systems by building upon the existing fixed threshold comparator structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces an intermediate variable threshold that acts as a mediator between the fixed threshold comparator and the actual power supply voltage. This intermediate element adapts the fixed threshold mechanism to work effectively with negotiated power delivery values, ensuring protection without requiring a complete redesign of the detection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the threshold is adjusted dynamically based on negotiated setpoint values, then protection accuracy is improved, but the control circuit complexity increases

Engineering Contradiction:
Improveprecision of overvoltage detectionVSAvoidcomplexity of control circuit
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic threshold adjustment through a control circuit that modifies the detection threshold based on the negotiated setpoint value. This dynamic approach improves measurement precision for overvoltage detection while managing control circuit complexity by integrating the threshold adjustment function into the existing power management architecture.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the negotiated setpoint value is fed back to the threshold adjustment circuit, which then sets the appropriate detection threshold. This feedback loop ensures precise overvoltage detection adapted to actual power delivery conditions while maintaining manageable control circuit complexity through systematic feedback control.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3836329B1Surge protector
Publication Date: 2023.03.08 STMICROELECTRONICS INC
  • EP3836329B1 patent drawingFigure 1
  • EP3836329B1 patent drawingFigure 2
  • EP3836329B1 patent drawingFigure 3

AI summary

This description relates to a power interface (414) comprising: a first switch (309) connecting an input terminal (301) of the interface to an output terminal (305) of the interface; a voltage divider (311) connecting the input terminal (301) to a reference node (313) configured to receive a reference potential (GND); a comparator (323) having a first input connected to a first node (319) of the divider and a second input configured to receive a constant potential (Vth); a digital-to-analog converter (DAC); a second switch (329) connecting an output of the converter (DAC) to a second node (321) of the divider (311); and a first circuit (331) configured to control the second switch (329) and the converter (DAC), in which a control of the first switch is determined by an output signal (comp_sig) of the comparator (323).