Programmable Current Limit Circuit for Power Supplies

The patent implements a dynamic current limit mechanism where the current limit value is not fixed but varies according to the programmable output voltage setting. The control circuit continuously adjusts the current limit based on the relationship between output voltage and switching current, enabling the system to adapt to different operating conditions while maintaining safety without requiring overly complex additional circuitry.

The patent employs a feedback mechanism where the control circuit monitors the output voltage and switching current, then adjusts the current limit accordingly. The PWM circuit receives feedback about the actual operating conditions and modulates the switching signal to maintain the current within safe limits while achieving the desired output voltage, thus improving safety through intelligent control rather than complex hardware.

The patent makes the current limit dynamic by linking it to the programmable output voltage setting. As the output voltage is programmed to different values, the current limit automatically adjusts to appropriate levels. This dynamic adjustment ensures that the current limit remains effective across the full range of programmable output voltages and input voltage variations, maintaining reliability while preserving adaptability.

The patent changes the parameter of current limit based on the output voltage setting and operating conditions. By varying the current limit parameter in response to changes in output voltage and input voltage, the system maintains effective current protection across all programmable operating conditions, resolving the contradiction between adaptability and reliability.

The patent designs the control circuit to perform multiple functions: voltage regulation, current limiting, and adaptive adjustment all within a single integrated PWM control architecture. The same control circuit that regulates the output voltage also dynamically adjusts the current limit based on the operating conditions, eliminating the need for separate dedicated circuits and minimizing overall complexity while achieving improved efficiency through dynamic adjustment.

The control circuit automatically adjusts the current limit based on the programmed output voltage and actual operating conditions without requiring external intervention or complex additional control logic. The system serves itself by using its own output voltage information to determine the appropriate current limit, simplifying the control architecture while achieving efficient adaptive current limiting.