Power Integrations range of CAPZero™ Integrated Circuits (ICs) are intelligent high voltage switches designed to reduce power losses in switching supplies that are linked with the X capacitor discharge resistors. The CAPZero Capacitor Discharge IC will allow designs to meet emerging no-load and standby power efficiency requirements.

The Power Integrations CAPZero Integrated Circuit (IC) will block current flow in the X capacitor safety discharge resistors when an AC voltage is present. This will result in a power loss of less than 5 mW at 230 Vac and will enable greater flexibility in selecting the appropriate X capacitors for specific applications, allowing optimization of differential mode EMI filtering.

When the AC supply voltage is disconnected the CAPZero operation will ensure compliance with safety regulations and automatically discharge the X capacitor via the discharge resistors. The CAPZero series will also work safely at lower voltages such as industrial 18 or 24 Vac supplies.

The CAPZero capacitor discharge Integrated circuit family are suitable for all AC-DC converter applications utilising X capacitors. They are two terminal devices and are available in two voltage grades, 825 V and 1000 V. Applications include TV/Monitors, notebook PCs, printers, workstation PCs, ultra-low/no-load adapters and devices that require ErP Lot 6 compliance.

CAPZero is a new class of products from Power Integrations that is designed to reduce unnecessary power loss in switching supplies associated with the X capacitor discharge resistors. When AC voltage is applied, CAPZero blocks current flow in the X capacitor safety discharge resistors, reducing the power loss to less than 5 mW at 230 VAC. When AC voltage is disconnected, CAPZero automatically discharges the X capacitor by connecting the bleed resistors in parallel. This operation allows total flexibility in the choice of the X capacitor to optimize differential mode EMI filtering and reduce inductor costs, with no change in power consumption.

Simplifies EMI filter design
Only two terminals
>4 mm creepage on package and pcb
High common mode surge immunity
High differential surge withstand
<5 mW consumption at 230 VAC

Capacitor Discharge ICs