Robinson, 27, had two interceptions and 39 combined tackles last season for the Saints.
He was the No. 32 pick in the 2010 draft out of Florida State by New Orleans and played the first five seasons of his career with the Saints. He has nine career interceptions.
The Chargers finished No. 9 in yards allowed and No. 13 in scoring defense last season. The defense was No. 4 in passing yards allowed but only No. 28 in interceptions.
San Diego finished last season 9-7.
- Jack Jorgensen