Driver warms up until the target temperature is reached, and then the micro-controller selects a lower output level (1/2 of the target current in this case). Once the chip is manually cooled by the really cold CO2, the software control loop resets the output to full current. On the last part of the video the driver warms up once more, and the output drops again. Each board is calibrated to account for chip-to-chip variation, and not only are the temperature set points programmable, but the hysteresis is of course fully programmable as well.
Post time: Jul-06-2017