A discharge lamp driving device includes: a discharge lamp driving unit which supplies drive power to a discharge lamp; and a control unit which controls the discharge lamp driving unit according to a waveform of the drive power. The waveform has n launching periods and a low-power mode lighting period. The n launching periods include a first launching period in which the drive power increases toward refresh power that is equal to or above drive power in a low-power mode and equal to or below rated power, and (n1) launching periods in which the drive power is maintained at the refresh power. The control unit, in an x-th launching period, supplies the discharge lamp with a drive current having a drive frequency equal to or below a drive frequency of a drive current supplied to the discharge lamp in an (x1)th launching period.

Provided are circuits and methods for a digital controller for an electronic ballast for a fluorescent lamp, comprising a feed-forward loop that provides information about a voltage firing angle, and a pulse width modulator that controls a duty ratio of at least one power switch of the electronic ballast according to the information. The digital controller may include a duty ratio controller implemented in the pulse width modulator. The digital controller may include one or more functions such as dimming, maintaining high power factor throughout the dimming range, low lamp power detection, lamp soft-start, and DC-link capacitor over-voltage detection for end of life protection or lamp failure protection. In one embodiment the ballast is a single stage, single switch ballast.