Charge Pump Overcurrent Detection Using Voltage Comparison
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Solution Overview
Problem
Existing overcurrent detection systems for charge pumps are inadequate in detecting excess currents in time, often resulting in damage to switches and posing safety hazards during fast charging of electronic devices.
Innovation Solution
An overcurrent detector system that includes a reference unit generating a reference voltage representing a predetermined threshold current, a detection unit generating a sensing voltage for the charging current, and an output unit producing an over-current-protection signal when the sensing voltage exceeds the reference voltage, allowing for rapid disconnection of the charging path to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional overcurrent detection systems are used, then the system structure is relatively simple, but the detection speed is slow resulting in switch damage
Solution Approach 1:
The patent replaces conventional slow overcurrent detection methods with a voltage-based detection mechanism that compares voltages across switches using differential amplifiers. This substitution enables nanosecond-level detection speed by leveraging voltage measurement and comparison rather than traditional current sensing methods, thereby resolving the contradiction between detection speed and system complexity.
Solution Approach 2:
The patent introduces voltage comparison as an intermediary mechanism to detect overcurrent conditions. By measuring and comparing voltages across switches through differential amplifiers, the system indirectly detects current excess conditions with high speed. This intermediary approach allows fast detection without directly measuring current, balancing detection speed requirements with acceptable system complexity.
2Reliability
If detection time is extended to microseconds, then the detection system can operate with simpler components, but the switches may already be damaged by excess currents
Solution Approach 1:
The patent implements preliminary protection by continuously monitoring voltages across switches and comparing them in real-time using differential amplifiers. This preliminary detection mechanism identifies overcurrent conditions before they cause switch damage, enabling preventive action. The continuous voltage comparison approach ensures that detection occurs in nanoseconds rather than microseconds, preventing damage before it happens.
Solution Approach 2:
The patent employs feedback through differential amplifiers that continuously compare voltages across switches and provide immediate feedback when voltage differences indicate overcurrent conditions. This feedback mechanism enables real-time detection and protection, ensuring that overcurrent conditions are identified and addressed before they can damage the switches, thereby improving reliability while minimizing detection time.
3Productivity
If voltage conversion is performed through switching operations, then charging efficiency is improved, but the magnitude of currents through switches becomes critical for safe operation
Solution Approach 1:
The patent uses voltage comparison as an intermediary safety mechanism that monitors the effects of switching operations without interfering with the efficient voltage conversion process. By comparing voltages across switches using differential amplifiers, the system detects excessive current conditions that result from switching operations while allowing the charge pump to maintain its high charging efficiency. This intermediary monitoring approach protects against damage while preserving productivity.
Solution Approach 2:
The patent replaces traditional current sensing methods with voltage-based detection to monitor switching operations. This substitution allows the charge pump to maintain efficient switching-based voltage conversion while using voltage comparisons across switches to detect harmful excess current conditions. The voltage-based approach enables protective detection without disrupting the efficient switching operations that provide high charging efficiency.
Data Source
AI summary
Overcurrent detector and method for a charging path of a charge pump. For example, an overcurrent detector for a charging path of a charge pump, the charging path including a switch associated with a switch on-resistance value, the charge pump being configured to receive an input voltage and generate an output voltage to charge a battery, the overcurrent detector including: a reference unit biased to the output voltage and configured to generate a reference voltage representing a predetermined threshold current for the switch of the charging path; a detection unit coupled to the reference unit and configured to generate a sensing voltage representing a charging current that flows through the switch of the charging path; and an output unit configured to generate an over-current-protection signal based at least in part on the reference voltage and the sensing voltage.