Semiconductor Device RF Circuit Loop-Back Switching for Function Safety

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing semiconductor systems lack the ability to automatically detect abnormalities in RF transmission and reception systems, which hinders the realization of function safety, especially in critical applications like vehicle-mounted radar devices.

Innovation Solution

The semiconductor device incorporates a transmission/reception loop-back switching unit that switches between normal and test modes, allowing for automatic detection of signal abnormalities and execution of detailed tests when a target object is detected, using a microcontroller to control the switching and perform frequency analysis to determine signal normalcy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a test mode is implemented to detect abnormalities in RF transmission and reception systems, then function safety is improved, but device complexity increases due to the need for additional switching units and test circuits

Engineering Contradiction:
Improvefunction safetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The transmission/reception loop-back switching unit serves dual purposes: it enables normal transmission/reception operations and simultaneously facilitates test mode operations for abnormality detection. By making the switching unit multi-functional, the patent avoids adding separate dedicated test equipment, thereby improving function safety while minimizing the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The RF circuit performs self-diagnosis by using its own transmission and reception circuits to generate test signals and detect abnormalities. The transmission circuit generates test signals that are routed back through the reception circuit, allowing the system to self-test without requiring external test equipment, thus improving reliability while keeping the device complexity manageable.

Inventive Principle:
Principle #25Self-service

2Reliability

If automatic abnormality detection is implemented, then function safety is improved, but manufacturing complexity increases due to the need for automated control systems

Engineering Contradiction:
Improvefunction safetyVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The microcontroller automatically controls the switching unit to alternate between normal operation mode and test mode without requiring external intervention. The system self-manages the test signal generation, routing, and abnormality detection processes, which simplifies manufacturing by eliminating the need for complex external automated test equipment while achieving automatic abnormality detection for function safety.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If detailed tests are executed when target objects are detected, then measurement precision is improved, but loss of time increases due to the additional testing procedures

Engineering Contradiction:
Improvemeasurement precisionVSAvoidloss of time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The switching unit alternates between normal operation mode and test mode in periodic intervals. During normal operation, the system performs its primary function; during designated test intervals, it executes detailed tests when target objects are detected. This periodic alternation allows the system to achieve high measurement precision through detailed testing while minimizing time loss by confining tests to specific periods rather than continuously.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3517984B1Semiconductor device and semiconductor system
Publication Date: 2020.11.04 RENESAS ELECTRONICS CORP
  • EP3517984B1 patent drawingFigure 1
  • EP3517984B1 patent drawingFigure 2
  • EP3517984B1 patent drawingFigure 3~4

AI summary

A semiconductor device includes an RF circuit and a microcontroller. The RF circuit has: a transmission unit generating a transmission signal; a reception unit generating a first generation signal and a second generation signal; and a transmission/reception loop-back switching unit switching between a first coupling state of coupling an output terminal of the transmission unit to a transmission antenna and coupling an input terminal of the reception unit to a reception antenna and a second coupling state of coupling an output terminal of the transmission unit to the input terminal of the reception unit. The microcontroller switches the transmission/reception loop-back switching unit to the second coupling state and executes a test of the RF circuit on the basis of the second generation signal when the transmission/reception loop-back switching unit is in the second coupling state and an output signal of a first sensor circuit.