Redundant Sensor Self-Test Circuit for Faster Multi-Channel ADC Checks
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Solution Overview
Problem
Existing self-testing methods for IC devices with multiple input channels and redundancy are time-consuming and inefficient, as they require testing all sensors and other components, such as multiplexers, which can be cumbersome and labor-intensive.
Innovation Solution
A self-testing circuit that includes a first plurality of analog-to-digital converters (ADCs) coupled to primary sensors, a first multiplexer (MUX) receiving outputs from these ADCs, a second MUX receiving outputs from redundant sensors, a second ADC, a checker circuit for comparing outputs from the primary and redundant sensors, and switches coupled between the second MUX and a reference voltage node, allowing for efficient self-testing by synchronizing the MUXs and injecting fault conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all sensors in all input channels are tested individually, then testing completeness is improved, but testing time increases
Solution Approach 1:
The patent combines multiple sensor tests into a single integrated testing process by using a shared ADC and multiplexer system. Multiple sensors from different input channels are multiplexed to a common ADC, allowing simultaneous or sequential testing of all sensors through a unified test architecture rather than individual separate tests.
Solution Approach 2:
The testing circuit is designed with universal components that serve multiple functions. A single ADC and multiplexer system is used to test all sensors across all input channels, making the testing apparatus multi-functional rather than requiring dedicated test equipment for each sensor.
2Reliability
If redundant sensors are tested along with primary sensors, then fault detection capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the testing of primary and redundant sensors into a single integrated circuit architecture. Both primary and redundant sensors are connected through the same multiplexer and ADC system, allowing unified testing without requiring separate test paths or additional complex circuitry.
Solution Approach 2:
The IC device performs self-testing of its own sensors including redundant sensors through internal circuitry. The device uses its own ADC and multiplexer resources to test its sensors without requiring external test equipment, thereby detecting faults in both primary and redundant sensors while avoiding additional external testing complexity.
3Reliability
If multiplexers are tested during self-testing, then component coverage is improved, but testing time increases
Solution Approach 1:
The patent combines multiplexer testing with sensor testing into a single integrated process. The multiplexer is tested while it is performing its normal function of routing sensor signals to the ADC, allowing simultaneous testing of both the multiplexer and the sensors without requiring separate dedicated multiplexer test sequences.
Data Source
AI summary
A circuit includes: first analog-to-digital converters (ADCs) configured to be coupled to respective ones of first sensors; a first multiplexer (MUX) coupled to output terminals of the first ADCs; a second MUX configured to be coupled to second sensors which are redundant sensors for the first sensors; a second ADC coupled to an output terminal of the second MUX, the first MUX and the second MUX being controlled by a selection signal; a first checker circuit configured to compare a first data at an output terminal of the first MUX with a second data at an output terminal of the second ADC; and a plurality of switches coupled between respective ones of the input terminals of the second MUX and a reference voltage node.