Radiation Detector ASIC Test Circuitry for Failure Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radiation detector assembly testing methods in CT systems assume uniform x-ray radiation and cannot distinguish between detector array and ASIC signal processing issues, leading to unnecessary replacement of entire modules.
Innovation Solution
Incorporating test circuitry within the ASIC to inject and measure test electrical pulses, allowing for independent testing of signal processing without radiation, and using a processor to differentiate between detector array and ASIC failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiation detector assembly testing is performed using x-ray radiation under controlled conditions, then the detector operation can be validated, but the test cannot distinguish between detector array failures and ASIC signal processing failures
Solution Approach 1:
The test circuitry is segmented into separate functional components: a charge pulse generator that injects test signals and a current meter that measures responses. This segmentation allows independent testing of the ASIC signal processing circuitry from the detector array, enabling identification of which component is failing.
Solution Approach 2:
Test circuitry is introduced as an intermediary between the detector array and the external testing system. This intermediary provides a controlled interface for injecting test signals and measuring responses, enabling differentiation between detector array failures and ASIC failures without requiring full module replacement.
2Ease of operation
If uniform x-ray radiation assumption is made during testing, then testing procedure is simplified, but test results reflect spatial nonuniformity of x-ray radiation causing false failures
Solution Approach 1:
The charge pulse generator pre-establishes a known reference signal before the actual detection process. By injecting a predetermined test pulse with known characteristics, the system creates a baseline for comparison that compensates for spatial nonuniformities in x-ray radiation, allowing accurate assessment of detector response independent of radiation distribution.
Solution Approach 2:
The testing method changes from passive x-ray radiation measurement to active electrical signal injection. By transforming the test from optical/radiation domain to electrical domain, the system gains precise control over input parameters and eliminates dependence on x-ray radiation uniformity, thereby improving measurement precision while maintaining procedural simplicity.
3Reliability
If entire module replacement is performed when detector fails test, then system reliability is restored, but costs increase and maintenance time increases due to unnecessary replacement of functional components
Solution Approach 1:
The test circuitry (charge pulse generator and current meter) is extracted as a separate functional unit within the ASIC. This extraction enables independent testing and diagnosis of signal processing circuitry without involving the entire detector module, allowing replacement of only the specific failed component rather than the whole module.
Solution Approach 2:
The current meter provides feedback about the ASIC's response to injected test pulses. This feedback mechanism enables real-time diagnosis of signal processing failures, allowing maintenance personnel to identify exactly which component is faulty and replace only that component, improving maintenance efficiency while restoring system reliability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A radiation detector assembly (20) includes a detector array module (40) configured to convert radiation particles to electrical detection pulses, and an application specific integrated circuit (ASIC) (42) operatively connected with the detector array. The ASIC includes signal processing circuitry (60) configured to digitize an electrical detection pulse received from the detector array, and test circuitry (80) configured to inject a test electrical pulse into the signal processing circuitry. The test circuitry includes a current meter (84) configured to measure the test electrical pulse injected into the signal processing circuitry, and a charge pulse generator (82) configured to generate a test electrical pulse that is injected into the signal processing circuitry. The radiation detector assembly (20) is assembled by operatively connecting the ASIC (42) with the detector array module (40), and the signal processing circuitry (60) of the ASIC of the assembled radiation detector assembly is tested without the use of radiation.