The machine vision system uses very short strong light flashes to produce high-speed images for various data processing applications. For example, a fast-moving conveyor belt performs fast labeling and defect detection through a machine vision system. Infrared and laser LED flash lamps are commonly used in short-range and motion detection machine vision. The security system sends out high-speed, imperceptible LED flash to detect motion, capture and store security images.

A challenge for all these systems is to generate very high current and short-time (microsecond) led camera flash waveforms that may spread over a long period of time, such as 100 ms to more than 1 s. It is not easy to generate short-time LED flash square wave with long interval. When the driving current of LED (or LED string) rises to more than 1 A and the LED on time is shortened to a few microseconds, the challenge becomes more difficult. Many LED drivers with high-speed PWM capability may not be able to effectively process high current with long off time and short time without reducing the square wave quality required for proper processing of high-speed images.