USB PD Interface Circuit for Dynamic Current Control
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Solution Overview
Problem
Known USB PD interfaces face limitations in managing power delivery and current control, particularly when devices need to handle varying power demands and renegotiate supply power, leading to inefficiencies and potential overloading.
Innovation Solution
The proposed USB PD interface design includes a circuit with a PMOS transistor, PNP transistor, and operational amplifier configurations to control current and power delivery, using resistors, capacitors, and diodes to manage inrush currents and power renegotiation efficiently, ensuring stable power delivery and preventing overloading.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If USB PD interface uses simple resistor-based current control, then device complexity is reduced, but current control precision and protection capability deteriorate
Solution Approach 1:
The patent employs transistors with controllable base-emitter or gate-source voltages to dynamically adjust current flow, replacing fixed resistor-based control. By varying the voltage parameters across transistor terminals, the circuit achieves precise current regulation and protection functionality without requiring complex multi-component networks.
Solution Approach 2:
The interface incorporates feedback mechanisms where the state of transistors (on/off conditions based on voltage thresholds) is continuously monitored and fed back to control circuits. This enables automatic adjustment of current delivery based on real-time device conditions, improving current control precision while maintaining manageable circuit complexity through integrated control logic.
2Reliability
If USB PD interface implements robust current limiting and overcharge protection, then device reliability improves, but interface complexity increases
Solution Approach 1:
The transistor-based control circuit is designed to automatically respond to overcurrent and overcharge conditions without external intervention. When voltage thresholds are exceeded, the transistors self-regulate or shut off, providing built-in protection functionality that enhances reliability while keeping the control logic contained within a compact circuit structure.
Solution Approach 2:
The interface circuit includes preliminary protective measures where transistors are configured to prevent harmful current flow before it can damage the device. By setting appropriate voltage thresholds and transistor switching characteristics, the circuit proactively blocks potential overcurrent or reverse voltage conditions, ensuring reliable operation under varying load conditions.
3Device complexity
If USB PD interface uses fixed voltage thresholds for transistor control, then circuit simplicity is maintained, but adaptability to varying power demands deteriorates
Solution Approach 1:
The patent implements dynamic voltage threshold adjustment where the control voltages for transistors are not fixed but can vary based on operational conditions. The control circuit adjusts the base-emitter or gate-source voltages dynamically in response to changing power demands, enabling the interface to adapt to different delivery scenarios while maintaining a relatively simple transistor-based architecture.
Solution Approach 2:
The interface changes operational parameters such as transistor switching thresholds and control voltages to match varying power delivery requirements. By modifying these electrical parameters dynamically, the circuit achieves high adaptability to different load conditions and power negotiation scenarios without requiring a completely redesign of the control architecture.
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
This design effectively limits inrush currents, adapts to varying power demands, and prevents overloading by dynamically controlling the base-emitter voltage and gate-source voltage of transistors, ensuring stable power delivery and protecting devices from voltage fluctuations.
Implementation Method 1
a first circuit configured to deliver a control potential to a base of the second transistor determined from a current in the first resistor
Implementation Method 2
a first MOS transistor connected between the fifth node and the second node
Implementation Method 3
a second bipolar transistor having a collector connected to a gate of the first transistor and an emitter connected to the fourth node or to the fifth node
Data Source
AI summary
The present disclosure relates to an USB PD-type interface including a first node receiving a first potential, a second node delivering a second potential, and a third node at a reference potential; a resistor connected between a fourth node coupled to the first node, and a fifth node; a MOS transistor connected between the fifth node and the second node; a bipolar transistor having a collector connected to a gate of the MOS transistor and an emitter connected to the fourth node or the fifth node; and a circuit configured to deliver a control potential to a base of the bipolar transistor determined from a current in the first resistor.