Electrical Characterization
In-circuit testing utilizes a stimulus-response technique to evaluate passive and active components on a populated printed circuit board without powering up the entire assembly. To achieve this, analog vector profiling maps the complex impedance response of individual component pins by applying low-voltage alternating current signals to specific circuit nodes. This analog vector profiling approach measures the phase angle and magnitude of the current to isolate the board from external noise.
The resulting measurement identifies deviations in resistance and capacitance.
Measurement Protocol
Sinusoidal signals are injected through test probes into the target circuit node while the current flowing into the node is recorded. The resulting analog vector profiling signature represents the parallel combination of all resistive, capacitive, and inductive elements connected to that node. Comparing these vectors against a known-good board identifies discrepancies that indicate faulty parts or wrong values.
Failure Identification
Solder bridges, open joints, and damaged silicon junctions alter the impedance profile of the node. In assembly environments where dense packaging restricts physical probe placement, analog vector profiling allows verification of multiple connections through a single accessible test pad. It provides high defect coverage by detecting structural assembly errors before the board progresses to functional verification.
