John Noble, 43, of Horrabridge, Devon, admitted causing the death of Chris Dennehy, 58, by careless driving on the A38 near Lee Mill in September 2014.
He was previously cleared of causing Mr Dennehy's death by dangerous driving.
Noble was sentenced to 24 weeks, suspended for two years, at Plymouth Crown Court.
Experts told the court he may only have had two seconds to react after the cyclist came into view.
Noble's lorry hit Mr Dennehy, who lived in Plymouth, from behind on the Exeter-bound carriageway.
The court heard Noble later told a colleague he had been reaching across his cab to play a sermon on his mobile phone just before hitting the cyclist, adding that his vehicle must have drifted across the carriageway.
Noble was also banned from driving for 18 months, ordered to carry out 250 hours of unpaid work and given a 12-month supervision order.
A lorry driver who reached over to play a sermon on his mobile phone moments before he hit and killed a cyclist has been given a suspended jail term.