LinkZero-AX ICs provide a very simple circuit for controlled power-down and wake-up. But because this method doesn’t use any relay circuits, the AC supply is always connected to the entire system, including the auxiliary power supply and EMI filter. A typical appliance circuit may use X-capacitor discharge resistors in the EMI filter, and line sense resistors for the microcontroller. These resistors are a constant load on the input, even during the off-mode, increasing standby consumption. For the lowest possible standby power, CAPZero and SENZero devices should be used to disconnect the discharge resistors and sense resistors when not in use.