Soft-Start Converter Overload and Short Circuit Protection
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Solution Overview
Problem
Conventional converters face premature shutdown issues due to overload and output short conditions, leading to potential switch damage during minimum turn-on times, as they lack effective control over drain current during these states.
Innovation Solution
A switch controller that determines output short and overload states using detection signals and feedback voltages, terminating the switching operation when either condition is detected, with a delay time to prevent noise interference and ensure accurate state determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the converter shuts down when drain current reaches threshold value during overload or output short, then the converter is protected from damage, but premature shutdown occurs before normal operation can begin
Solution Approach 1:
The patent introduces a soft-start period that activates before normal operation begins. During this preliminary phase, the converter operates with relaxed protection thresholds, allowing it to establish normal operation before standard overload and short-circuit protection mechanisms become active. This prevents premature shutdown by ensuring protection only engages after the converter has successfully entered its normal operating state.
2Stability of the object's composition
If the converter has minimum turn-on time due to internal delay and leading edge blanking, then the switching operation is stable, but excessive drain current flows through the switch during this period when output is shorted
Solution Approach 1:
The patent implements a feedback mechanism that continuously monitors the output voltage or current during the minimum turn-on period. When an output short condition is detected through this feedback, the system immediately terminates the switching operation, preventing excessive drain current from damaging the switch while maintaining stable switching operation under normal conditions.
3Reliability
If the converter terminates switching operation during startup, then protection from output short is achieved, but the converter cannot complete its startup sequence
Solution Approach 1:
The patent establishes a soft-start period as a preliminary phase that separates startup from normal operation. During this soft-start period, the converter allows switching operations to continue even when output short conditions are detected, as the primary goal is to complete the startup sequence. Only after the soft-start period ends and normal operation begins does the converter enforce strict protection that terminates switching upon detecting output shorts.
Data Source
AI summary
A converter and a driving method thereof are provided. The converter can determine the output short state of the converter after the soft start is finished by using a detection signal that corresponds to an input signal while a switched is turned on and that corresponds to an output signal while the switch is turned off, so as to convert the input signal into the output signal according to a switching operation of the switch. The converter can determine the overload state of the converter by using a feedback voltage corresponding to the output signal, and terminate the switching operation when the converter is in an output short state or overload state.