Circuits and methods for transmission of digital data between two or more devices via powerline particularly suited for use in high attenuation, high noise commercial/industrial powerline environments, including transmission of pulses generated by a capacitor charged in the positive half cycle of the sine wave and discharged during the negative half-cycle, placing the pulse at one of two predetermined signal timing positions related to zero voltage crossing points or to previously transmitted pulses so that the pulses are substantially in the powerline temporal quiet zone near zero crossing and so that the powerline voltage at the time of the pulse is additive to the capacitor voltage.