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. Technical support is available from the Power Integrations website at: www.power.com/products/capzero-3.
About Power Integrations
Power Integrations, Inc. is a leading innovator in semiconductor technologies for high-voltage power conversion. The company’s products are key building blocks in the clean-power ecosystem, enabling the generation of renewable energy as well as the efficient transmission and consumption of power in applications ranging from milliwatts to megawatts. For more information please visit www.power.com.
Power Integrations, CapZero, and the Power Integrations logo are trademarks or registered trademarks of Power Integrations, Inc. All other trademarks are the property of their respective owner.