Dante De Guzman of XP Power explains the meaning of patient leakage current for medical power supplies and describes several ways of reducing this leakage current for the most stringent medical applications.
leakage current is often the hardest part of the standard to meet. This leakage current is directly proportional to the input to output capacitance of the power supply, but reducing this capacitance is not always easy because of EMI concerns. Adding a DC-DC converter as an extra layer of isolation is one solution, though it may be costly. Custom power design is a feasible but unpopular option. Alternatively, XP Power works with customers to modify its standard medical power supplies to meet the most stringent patient leakage current requirements, which may be the most cost-effective option.