It is designed to eliminate the energy loss caused by the safe discharge of the X capacitors of utility equipment using only resistors-Power Integrations' CapZero series of auto-discharge ICs.
X capacitors are connected from line to line at the AC input, preventing electromagnetic interference from returning to the grid. New safety standards, such as IEC 62368-1, place increasing emphasis on discharging capacitors during power outages to prevent the risk of electric shock. The shunt resistor is effective, but it can consume about 20mW or more power even in standby or power-down mode. This prevents compliance with the requirements of eco-design standards, such as external power regulations and ErP Lot 6.
When AC power is connected, inserting a Power Integrations CapZero IC in series prevents current from flowing to the resistor, reducing power consumption to less than 5mW. When the power is disconnected, CapZero is activated to discharge the capacitor with a time constant of less than one second.
CapZero not only saves power, but also uses a larger X capacitor value to enhance EMI suppression. The IC family enables designers to choose the right device with a total X capacitance from 500nF to 5µF. The company said that it can provide 825V or 1000V voltage levels, which can flexibly meet various surge requirements.
