The trio would have become unrestricted free agents on March 14 had the team not picked up the extra years.
Dotson started all 11 games he played last season before a torn posterior cruciate ligament in his knee ended his campaign. The 32-year-old is the longest-tenured member of the team as he is entering his 10th season with Tampa Bay.
Conte recorded 77 tackles, a career-high three forced fumbles and one interception in 16 games last season. The 29-year-old has collected 456 tackles, 14 interceptions, six forced fumbles and two fumble recoveries in seven NFL seasons with the Buccaneers and Chicago Bears.
Robinson notched five special teams tackles and two forced fumbles in the season finale versus New Orleans, one of which was recovered and returned for a touchdown.