Power Integrations unveiled the CAPZero-3, their latest X-capacitor discharge ICs, in values from 100 nF to 6 µF. The two-terminal devices enable designers to meet IEC60335 safety approvals for major appliances, the discharge safety standard. To provide protection from an electrical hazard, the spec requires the voltage across the input X capacitor to discharge to less than 34V 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.
Offering high common-mode surge immunity, CAPZero-3 ICs can be placed before or after a system’s input fuse, and no external ground connection is necessary. Features include a high differential surge withstand, due to 1000 V internal MOSFETs, while creepage on the package and PCB is maintained at greater than 4mm.
Safety-certified to CB and Nemko requirements, the devices do not require 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.
Learn more at www.power.com/products/capzero-3.