A man who became suicidal from grief after running over a cyclist at Old Noarlunga in Adelaide's south has been sent to jail for a minimum of 10 months.

Darren James Rudland pleaded guilty to a death by dangerous driving charge, after hitting and killing Alistair Smith, 50, on the Victor Harbor Road in January.

The court heard he had been labouring in vineyards in 45-degree heat and drank beers after work to cool down before he decided to drive home.

After hitting the cyclist, he fled the scene, but made full admissions to police a short time later.

Judge Michael Boylan set a lower-than-usual non-parole term because of Rudland's overwhelming remorse.