When AC voltage is applied, CAP300DG blocks current flow in X capacitor safety discharge resistors, reducing power loss to less than 5mW or essentially zero at 230VAC. When AC voltage is disconnected, it automatically discharges X capacitor by connecting series discharge resistors. This allows total flexibility in choice of X capacitor to optimize differential mode EMI filtering and reduce inductor costs with no change in power consumption. Designing with CAP300DG is simply a matter of selecting appropriate external resistor values for X capacitor value being used to achieve necessary time constant. Simplicity and ruggedness of two terminal CAP300DG IC makes it an ideal choice in systems designed to meet ErP Lot 6 requirements. Used in all AC-DC converters with X capacitors of 100nF up to 6µF, appliances requiring ErP Lot 6 compliance, adapters requiring ultra-low no-load consumption, all converters requiring very low standby power and lossless generation of zero crossing signal.