CMOS Rolling Shutter Exposure Timing for Pulsed Strobe Systems
CMOS rolling shutter strobe integration requires setting exposure longer than array sweep time to fire flashes during full-frame overlap windows.
Strobe Driver Jitter
Timing Uncertainty
A temporal variation in the onset of an illumination trigger signal introduces instability in high-speed optical measurements. This strobe driver jitter represents the standard deviation of the delay between the trigger input and the actual light pulse output. It degrades the consistency of the exposure time in high-speed cameras, which leads to variations in the captured light intensity.
Minimizing this variation is necessary to maintain high repeatability in vision-based quality control.
Electrical Origin
Power supply noise and electromagnetic interference are the primary sources of timing variations in the driver circuits. Fluctuations in the voltage rails affect the switching thresholds of the logic gates, which introduces random variations in the trigger propagation delay. Thermal noise in the semiconductor switches further contributes to this temporal uncertainty, especially at elevated operating temperatures.
Metrology Strategy
Quantifying these sub-nanosecond variations requires a high-performance oscilloscope with a low jitter noise floor. The instrument calculates the root-mean-square value of the time difference between the input trigger and the leading edge of the light pulse. Temperature testing confirms the stability of the timing circuit across the specified range.
Application Hazard
Excessive timing instability can cause the light pulse to fall outside the exposure window of the imaging sensor. This mismatch results in partially illuminated images, which can lead to false defect detections in automated systems.