The deal announced Wednesday will keep Braun under contract through the 2019-20 season. Braun has one year remaining on his current contract.
Braun emerged as one of San Jose's top defensemen last season, often drawing the most difficult matchups. He was second on the team in average time on ice per game (20:59), tied for first in short-handed ice time per game (2:11) and set career-highs for points (17), goals (4) and assists (13).
Braun also added two points (one goal, one assist) in seven Stanley Cup playoff games.
The Sharks open training camp Friday.