2011’s uncapped were hosted on vitaminwater.com, but the team wanted to get even bigger and better in the second year of the program. To do that, vitaminwater® chose to partner with YouTube to bring critical scale to uncapped in 2012.

2012’s uncapped involved a series of live music events hosted across 9 U.S. cities, but this time, over 50 exclusive videos featuring performance coverage, behind the scenes footage, and artist interviews from uncapped were posted on a custom YouTube brand channel. The program was supported by Google ads, including YouTube’s TrueView ads and multiple homepage mastheads.

vitaminwater® had identified music as a common passion point between its brand and its audience, multicultural millennials, and now, they were not only creating authentic engagement with their audience with live events, but alsoAC/DC open frame switching power supply was also dropping for 15ms. That explained why the DUT was affected by EFT. I rejected the hypothesis. The mystery was the AC/DC power supply. Why was the output voltage dropping?

The Root Cause

EFT bursts applied on the AC line, which is the primary of the AC/DC transformer were common mode coupling onto the secondary due to the capacitance between the primary winding of the transformer and the secondary winding and due to stray capacitance on the board. When bursts got onto the secondary side, one of the effects they had was a ground bounce. Given that the power supply is a switching power supply, the microcontroller driving a MOSFET on the DC output was getting into an unknown state when its reference