The voltage drop exits along the FPC and related to the current, FPC copper thickness. Thus in the actual application, the LED strip light could not be in serial at infinite length. The typically lighting for LED strip is 5 meters when powered from 1 end and 10 meters when power from 2 end, because when the length is over 5 meters, there will occurs brightness difference from beginning to the end.
When the install the LED strip light over 5 meters, we will need to wiring each 5 meters in parallel or wiring from both ends(please note that need connect to same power supply when wiring from 2 ends otherwise the different PWM dimming from 2 power supply will damage the LED strip and cause failure).
However, sometimes we don’t want to wire the LED strip in parallel or there is limitation from confined space. We could consider use LED strip with constant current IC management that allow at least 15 meters running without brightness difference when wiring from 1 end. The length could be longer than 15 meters when we apply small power, like the single color LED strip could be as long as 25 meters. At the same time, the IC works well with the PWM dimmer controller, so no worry on the dimming!
Moreover, we could use this LED strip when the customer is sensitive on the brightness decay in 5 meters.