Design and Implementation of a High Voltage Source for Biphasic Electrical Stimulators

Biphasic constant current (CC) stimulators are used in functional electrical stimulation applications. These stimulators require positive and negative high voltage (HV) sources in order to deliver the programmed CC pulses to load. For example, applying symmetrical biphasic CC pulses with 50 mA amplitude to a 1 kΩ load requires positive and negative supply rails of 50V and -50V, respectively. In this study, a HV source based on a switched inductance boost DC/DC converter and a switched capacitor voltage inverter is designed and implemented in order to satisfy the HV requirements of biphasic stimulators. Performance of the proposed HV topology is satisfactory for CC pulses of 35 mA applied to a 1 kΩ load.