Built-in Self-Test for Pre-Driver Circuits
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Solution Overview
Problem
Testing of pre-driver circuits in integrated circuits is costly and time-consuming due to the need for external automatic test equipment, which complicates test program repeatability and increases overall manufacturing costs.
Innovation Solution
A built-in self-test system within the integrated circuit, utilizing an internal time measuring unit and configurable voltage monitors, performs tests on pre-driver parameters such as delay times, slew rates, and output voltages, eliminating the need for external equipment by integrating a time measuring unit and pass/fail check module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external automatic test equipment is used to test pre-driver circuits, then measurement precision can be ensured, but testing cost and device complexity increase
Solution Approach 1:
The patent combines the time measuring unit and pass/fail check module directly into the pre-driver circuit board, merging the testing functions with the circuit under test. This integration eliminates the need for separate external test equipment, reducing device complexity while maintaining measurement precision through internal standardized measurement mechanisms.
Solution Approach 2:
The pre-driver circuit performs self-testing through built-in time measuring units and pass/fail check modules that automatically measure parameters like delay times and slew rates without external intervention. The circuit tests itself using internal resources, eliminating dependency on external automatic test equipment while ensuring accurate measurements.
2Reliability
If external automatic test equipment is used for pre-driver testing, then comprehensive parameter testing is possible, but testing time and cost increase
Solution Approach 1:
The time measuring unit and pass/fail check module are pre-integrated into the pre-driver circuit board during manufacturing, so that testing can begin immediately without setting up external equipment. This preliminary integration of testing capabilities eliminates setup time and enables rapid sequential testing of multiple parameters including delay times, slew rates, and output voltages.
Solution Approach 2:
The built-in testing system enables continuous testing operations without interruption for equipment setup or reconfiguration. The time measuring unit continuously measures parameters and the pass/fail check module continuously evaluates results, maintaining uninterrupted testing flow that reduces total testing time while ensuring comprehensive functionality verification.
3Measurement precision
If multiple test parameters are measured externally, then complete pre-driver characterization is achieved, but test program repeatability decreases
Solution Approach 1:
By merging the measurement and evaluation functions into the circuit board itself, the system eliminates variability introduced by external equipment setup and operation. The integrated time measuring unit and pass/fail check module provide consistent, repeatable measurements across multiple tests since they are permanently installed and configured on the pre-driver board, ensuring identical testing conditions every time.
Solution Approach 2:
The self-testing capability ensures repeatable results by automatically performing the same measurement sequence without human intervention. The built-in time measuring unit and pass/fail check module execute standardized test routines consistently, eliminating operator-dependent variations and improving test program repeatability while maintaining comprehensive parameter measurement.
Data Source
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AI summary
A system for testing comprising an electronic circuit to be tested and an automatic testing equipment, said electronic circuit (10; 10'; 10"; 10‴) to be tested comprising a stage (122a, 122b) configured to supply a driving signal to a load, said stage (122a, 122b) comprising a pullup switch (122a) coupled to the voltage supply (VS) and a pulldown switch coupled to a lower potential than the voltage supply (GND, S), in particular ground, coupled to each other in an output node (G), and a pre-driver stage (12) comprising pre-driver circuits (121a, 121b) which output is coupled to the control input of respective pullup (122a) and pull down (122b) switch of the stage (122a, 122b) configured to supply a driving signal to a load, said electronic circuit (10; 10'; 10"; 10‴) to be tested comprising circuits (11, 14) for testing the pre-driver stage (12) under the control (SCMD) of the automatic testing equipment (20; 20'; 20"; 20‴) comprising a test logic module (11) configured to operate a built-in test sequence comprising test commands (PU CMD, PD CMD) for the pre-driver stage under the control of an external test signal (SCMD) issued by the automatic test equipment, the automatic test equipment (20, 20', 20") comprising a test load (211) to be coupled to said output node (G) of the stage (122a, 122b) configured to supply a driving signal to a load, said system for testing comprising a time measuring unit (14) configured to measure duration of signals at the output (G) of the stage (122a, 122b) configured to supply a driving signal to a load coupled to a pass fail check module (145), configured to evaluate if said duration of signals at the output (G) of the stage (122a, 122b) configured to supply a driving signal to a load satisfies a pass criterion, wherein said time measuring unit (14) is comprised in said electronic circuit to be tested and it started and stopped under the control of commands including commands ((PU CMD, PD CMD, SEL) issued by said logic (11) during execution of said bult-in test sequence.