Switched-Capacitor Converter Clamp Control for Lower Voltage Stress
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Solution Overview
Problem
Existing switched-capacitor voltage converters have fixed conversion ratios and require high-cost components with high withstand voltages when the input voltage exceeds a certain threshold, leading to increased manufacturing costs.
Innovation Solution
Incorporating a switched-capacitor voltage conversion circuit with a loop regulator and clamp circuits, including first and second clamp transistors, to dynamically adjust the voltage relationship between input and output, using a charge pump to stabilize electrical parameters and reduce transistor withstand voltage requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the input voltage Vbus is greater and the switched-capacitor voltage converter stops operating, then components with greater withstand voltage are needed, but manufacture costs increase
Solution Approach 1:
The patent introduces a dynamic control mechanism where the transistor QB is fully turned on during normal operation to maintain input voltage equal to reference voltage, and turned off during stop operation to disconnect input and output terminals. This dynamic switching allows the system to adapt its voltage handling requirements based on operational state, enabling use of lower withstand voltage components during stop conditions while maintaining reliability during operation.
Solution Approach 2:
The patent introduces an intermediary control mechanism through the loop regulator circuit and clamp circuit that mediates the voltage relationship between input and output. The loop regulator dynamically adjusts the voltage at the reference terminal PMID, and the clamp circuit ensures proper voltage levels during stop operation, allowing the system to maintain voltage isolation and protect components without requiring excessive withstand voltage margins.
2Device complexity
If fixed ratio conversion is implemented, then circuit structure is simplified, but adaptability to different voltage requirements is limited
Solution Approach 1:
The patent implements a dynamic voltage regulation system where the loop regulator continuously monitors and adjusts the voltage at the reference terminal PMID based on feedback. This dynamic control enables the output voltage to be precisely regulated at half the reference voltage regardless of input voltage variations, providing adaptability without requiring multiple fixed-ratio circuits or complex switching networks.
Solution Approach 2:
The patent changes the operating parameters of the switched-capacitor voltage conversion circuit by dynamically adjusting the reference voltage level through the loop regulator. By varying the reference voltage parameter in response to different operating conditions, the system achieves flexible output voltage control while maintaining a relatively simple fixed-ratio conversion structure.
Data Source
AI summary
A switched-capacitor voltage converter including a switched-capacitor voltage conversion circuit, a loop regulator circuit, a first clamp transistor, a second clamp transistor, a first clamp circuit, and a second clamp circuit is provided. The loop regulator circuit is configured to monitor electrical parameters of any one or both of an input terminal and an output terminal of the switched-capacitor voltage converter, and output a voltage to a gate of the first clamp transistor or the second clamp transistor according to one or more electrical parameters to stabilize the one or more electrical parameters at their corresponding target values. According to the present disclosure, the loop regulator circuit is additionally configured in the switched-capacitor voltage converter, and two back-to-back clamp transistors are disposed between the input terminal and a reference terminal of the switched-capacitor voltage converter.