Power Integrations has introduced CAPZero-4, the fourth generation of its X-capacitor discharge IC family, designed to reduce no-load and standby power consumption in AC-DC power supplies. The devices target consumer appliances, power adapters, displays, and industrial equipment operating under increasingly strict energy-efficiency requirements.
X-capacitors are commonly used in AC power supplies to suppress electromagnetic interference, but they can retain a charge after equipment is disconnected from the mains. Discharge resistors provide a path to safely dissipate that stored energy, although they also consume power whenever the equipment is connected.
CAPZero-4 addresses this loss by disconnecting the discharge resistor during normal operation and reconnecting it when AC power is removed. According to Power Integrations, the approach can reduce system no-load and standby input power by up to 1,000mW, preserving more of the available power budget for other circuitry.
The new devices consume less than 0.75mW at 230VAC and support AC-DC converters with line-to-neutral X-capacitance ranging from 100nF to 6µF. The family also extends the operating temperature range to -40°C to 125°C, making it suitable for industrial and outdoor equipment.
CAPZero-4 maintains package and pin compatibility with the previous CAPZero-3 generation, allowing existing designs to migrate with minimal hardware changes. Designers select external resistor values according to the required X-capacitor discharge time.
The devices are intended for applications requiring compliance with standby power limits, including ErP Lot 6 requirements, and support designs meeting applicable IEC, UL, and GB safety standards.
CAPZero-4 is currently in production and shipping to customers.
Learn More: https://www.power.com/products/capzero/capzero-4
