Diode With Sense Resistor for Accurate Current Sensing

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Solution Overview

Problem

Power electronics systems face challenges in accurately detecting fault conditions such as overcurrent and short circuits due to the inability to quickly and reliably sense current through diodes, leading to potential damage if not mitigated promptly.

Innovation Solution

A diode configuration with a sense resistor connected between the channel-stop pad and the cathode pad allows for accurate measurement of forward current by isolating the sense current from the main junction, enabling precise monitoring of circuit conditions without affecting the diode's operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional diode structure is used, then the device complexity is low, but the measurement precision of forward current is insufficient for accurate fault detection

Engineering Contradiction:

Improveforward current measurement precisionVSAvoiddiode structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The diode structure is segmented by introducing a channel-stop region that divides the current path into two separate paths: a main current path through the PN junction and a sense current path through the sense resistor. This segmentation allows independent measurement of forward current without affecting the main diode operation, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A sense resistor is introduced as an intermediary element connected between the channel-stop pad and cathode pad. This intermediary component enables precise current measurement by converting current into a measurable voltage drop, while the channel-stop region acts as an intermediary structure that directs a portion of the main current through the sense resistor without disrupting the primary diode function.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If current sensing is implemented in conventional diodes, then fault detection capability improves, but the sensing accuracy is insufficient for timely fault mitigation

Engineering Contradiction:

Improvefault detection capabilityVSAvoidcurrent sensing accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The channel-stop region and sense resistor are pre-configured into the diode structure during manufacturing, establishing the current division pathway before operation. This preliminary action ensures that during fault conditions, the sensing mechanism is already in place and immediately operational, enabling timely and accurate fault detection without requiring additional real-time configuration.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sense resistor provides continuous feedback about the forward current status by developing a voltage proportional to the current flowing through it. This feedback mechanism enables real-time monitoring of diode operation and immediate detection of abnormal current conditions, significantly improving reliability for fault mitigation.

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If a sense resistor is added to the diode, then current measurement capability is improved, but the manufacturing complexity increases

Engineering Contradiction:

Improvecurrent sensing functionalityVSAvoidmanufacturing process simplicity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The sense resistor is merged with the diode structure by connecting it between the channel-stop pad and cathode pad, which are existing structural elements of the diode. This merging approach integrates the sensing functionality into the diode's existing manufacturing process, avoiding the need for completely separate assembly steps and reducing overall manufacturing complexity despite adding sensing capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The channel-stop region serves multiple functions: it provides structural support for the sense resistor connection, divides the current into main and sense paths, and maintains the electrical characteristics of the diode. This multi-functionality reduces the need for additional dedicated components, simplifying manufacturing while enhancing adaptability for current sensing applications.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration provides accurate and reliable current sensing over a wide range of operating conditions, enabling timely detection of fault conditions and preventing damage in power electronics systems.

Implementation Method 1

A sense current is then measured through the sense resistor, and based on the measurement, the forward current through the diode is determined

Methodology Applied

Scientific EffectOhm's Law: Ohm's Law

Data Source

PatentUS10950596B2Diode with current sensor

Publication Date: 2021.03.16 SEMICON COMPONENTS IND LLC

AI summary

A diode with a current sensor is disclosed. The diode includes an anode region, a cathode region, and a channel-stop region. The diode further includes a sense resistor that is connected between the channel-stop region and the cathode region. When the diode is forward biased, a sense current flows through the sense resistor that corresponds to the forward current flowing through the diode. When the diode is reverse biased, the channel-stop region helps prevent a breakdown condition in the diode.