Methods and devices for performing ablation using time multiplexed waveforms are disclosed. The increased efficacy of monophasic waveforms is combined with the reduced side effects of biphasic waveforms by distributing components of the waveform across over a broader time interval than that typically used in a conventional biphasic waveform. Charge balancing occurs upon completion of therapy delivery within a time period that avoids muscle stimulation, while allowing unbalanced waveforms to be delivered during stimulation.