Semiconductor Module Open-Drain Signal Output Circuit

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Solution Overview

Problem

Existing semiconductor modules require an increase in the number of input/output terminals to output operation status information externally, leading to delayed detection of abnormalities and slower protection functions.

Innovation Solution

The semiconductor module incorporates signal output circuits with open-drain or open-collector configurations connected to an internal lead frame, allowing for centralized output of operation status information without increasing the number of terminals, enabling rapid detection and response to abnormalities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If each control circuit has its own external terminal for outputting operation status information, then abnormality detection capability is improved, but the number of input/output terminals increases

Engineering Contradiction:

Improveabnormality detection capabilityVSAvoidnumber of input/output terminals

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Multiple signal output circuits from different control circuits are merged into a single external terminal through wired-OR connection. The open-drain or open-collector output configurations allow multiple circuits to share the same terminal, enabling centralized output of operation status information without increasing terminal count.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

A single external terminal serves multiple functions by receiving signals from multiple control circuits. This universal terminal can indicate abnormalities from any of the controlled power semiconductor elements, making the terminal multi-functional rather than dedicated to a single control circuit.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If operation status information is output through a single shared terminal, then the number of terminals is reduced, but signal detection speed may be delayed

Engineering Contradiction:

Improvenumber of terminalsVSAvoidabnormality detection time

Core Design Contradiction:

Device complexityVSLoss of time

Solution Approach 1:

The patent replaces active pull-up resistors with passive wired-OR connection using open-drain or open-collector outputs. This substitution eliminates the need for active components that could introduce delays, allowing rapid detection when any control circuit asserts its abnormality signal by simply pulling the shared terminal to ground.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The wired-OR connection acts as an intermediary mechanism that combines multiple abnormality signals without requiring active signal processing. Any control circuit can immediately assert its status by pulling the shared terminal low, and this status is immediately detectable externally without processing delays.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9906009B2Semiconductor module

Publication Date: 2018.02.27 FUJI ELECTRIC CO LTD

AI summary

A semiconductor module which includes a plurality of control circuits that respectively drive a plurality of semiconductor elements on and off and a plurality of signal output circuits for the respective control circuits and which output operation status information, where the signal output circuits are respectively provided with signal output terminals having an open-drain configuration, and the signal output terminals each are connected to an internal lead frame on which the power semiconductor elements and the control circuits are mounted.