High-Side IPS Overcurrent Latch Timing for Safe Shutdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional high-side intelligent power switches (IPSs) in automotive applications face challenges in effectively managing overcurrent situations, leading to potential failures due to inadequate detection and response mechanisms, which can result in overheating and malfunction.
Innovation Solution
A semiconductor device with an overcurrent detection circuit and a logic circuit that outputs a pulse to turn on the power semiconductor element for a predetermined period after detecting an overcurrent situation, ensuring safe shutdown and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional overcurrent detection mechanisms are used in high-side IPSs, then the device can detect overcurrent situations, but the response time is insufficient leading to potential failures and overheating
Solution Approach 1:
The patent applies preliminary action by pre-configuring the logic circuit with a pulse generation circuit that can immediately generate a turn-off pulse when overcurrent is detected. The system prepares the power semiconductor element for rapid shutdown by having the detection circuit and response mechanism ready in advance, eliminating delays in the detection-response cycle and ensuring immediate protection against overheating.
2Temperature
If the power semiconductor element is turned off immediately upon overcurrent detection, then overheating is prevented, but the control unit may not have sufficient time to acknowledge the overcurrent situation
Solution Approach 1:
The patent introduces an intermediary mechanism where the logic circuit acts as a mediator between the overcurrent detection circuit and the power semiconductor element. The logic circuit generates and outputs a turn-off pulse that immediately shuts down the power semiconductor element, while simultaneously providing notification to the control unit. This intermediary structure enables both immediate temperature protection and adequate information transmission to the control system.
3Measurement precision
If conventional detection circuits are used, then overcurrent situations can be detected, but the detection precision and response accuracy are insufficient
Solution Approach 1:
The patent merges the overcurrent detection function with the logic circuit that controls the power semiconductor element. By integrating the detection circuitry and control logic into a unified structure, the system achieves precise overcurrent detection and immediate response without requiring separate complex detection and control systems. This merging reduces overall device complexity while improving detection precision and response accuracy.
Data Source
AI summary
Upon an input of an input signal that instructs to turn on a power semiconductor element, a pulse generation circuit generates a pulse. Upon reception of the pulse, a gated latch circuit holds an overcurrent detection state of an overcurrent detection circuit. In response to the input of the input signal and an overcurrent situation having been detected, an overcurrent mode switching circuit outputs an inverted or non-inverted oscillation signal, which is obtained by inverting or not inverting an oscillation signal generated by an oscillation signal generation circuit depending on the overcurrent situation being detected before or after the input of the input signal, and also outputs an inverted oscillation signal obtained by inverting the oscillation signal. A timing determination circuit periodically turns on the power semiconductor element based on the inverted oscillation signal and frequency divided signals obtained by frequency dividing the inverted or non-inverted oscillation signal.