Embodiments of the present disclosure relate to a lamp driver for lamps used as a source of heat radiation in a thermal processing chamber. The lamp driver includes a power source, at least two DC/DC converters, each DC/DC converter connected with the power source in series, a direct connection between the at least two DC/DC converters, and a line that is attached to the direct connection and attachable to a reference voltage. A plurality of the lamp drivers may be utilized to power a plurality of lamps positioned in a grounded lamphead assembly. The electrical potential between the lamps and the grounded lamphead assembly is reduced, which reduces the risk of arcing between the lamps and the lamphead assembly.