  We use the boundary state formalism to provide the full conformal description
of (F,Dp) bound states. These are BPS configurations that arise from a
superposition of a fundamental string and a Dp brane, and are charged under
both the NS-NS antisymmetric tensor and the (p+1)-form R-R potential. We
construct the boundary state for these bound states by switching on a constant
electric field on the world-volume of a Dp brane and fix its value by imposing
the Dirac quantization condition on the charges. Using the operator formalism
we also derive the Dirac-Born-Infeld action and the classical supergravity
solutions corresponding to these configurations.
