X-capacitor discharge ICs help designs meet IEC60335 specs

Power Integrations announced CAPZero-3, the latest generation of the company’s energy-saving X-capacitor discharge ICs. Two-terminal CAPZero-3 ICs enable designers to easily meet IEC60335 safety approvals for major appliances, and cover all capacitor values from 100 nF to 6 µF.

IEC60335 is the discharge safety standard for all appliances. To protect the user from an electrical hazard, it requires the voltage across the input X capacitor to discharge to less than 34 V within less than one second after the AC is removed. CAPZero-3 ICs block current flow through the X-capacitor discharge resistors when the AC voltage is connected, and automatically discharge X capacitors through those resistors when the AC is disconnected. CAPZero-3 ICs simplify EMI filter designs while permitting the use of larger X capacitors, which in turn enables smaller inductive components to be used with no resulting change in power consumption.

CAPZero-3 ICs can be placed before or after a system’s input fuse. Devices deliver high common-mode surge immunity so that no external ground connection is necessary, and feature a high differential surge withstand due to 1000 V internal MOSFETs. Creepage on the package and PCB is maintained at >4 mm.

Comments Edward Ong, product manager, Power Integrations: “With the launch of the new CAPZero-3 ICs, designers can use one part to address a large range of applications in small and major appliances that require X capacitor values from 100 nF to 6 µF.”

CAPZero-3 devices are safety-certified to CB and Nemko requirements and so developers do not need to perform a separate safety test on the X-capacitor discharge circuit of the power supply. Devices are available now, priced at $0.31 in 1,000 piece quantities. g innovator in semiconductor technologies for high-voltage power conversion.