A method and a circuit for driving light emitting diodes (LEDs) in
multiphase are provided. A string of LEDs divided into groups connected
to each other in series is provided. Each group is coupled to ground
through separate conductive paths. A phase switch is provided in each
conductive path. Increasing the input voltage turn on the string of LEDs,
group by group in the sequence downstream the string. To reduce power
dissipation, the phase switch of an upstream group is turned off when
next downstream group is turned on.