The two-terminal ICs enable designers to easily meet IEC60335 safety approvals for major appliances. IEC60335 is the discharge safety standard for all appliances. To protect the user,it requires the voltage across the input X capacitor to discharge to less than 34V in less than one second after the AC is removed.

The ICs block current flow through the X-capacitor discharge resistors when the AC voltage is connected and automatically discharge X capacitors through the resistors when the AC is disconnected. They simplify EMI filter design, says the company, and allow the use of larger X-capacitors to enable smaller inductive components to be used without change in power consumption.

The 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. The use of 1,000V MOSFETs ensures a high differential surge withstand. Creepage on the package and PCB is maintained at 4.0mm and above.

 Designers can specify the ICs in projects that require X-capacitor values from 100 to 6 micro Farad.

The ICs are certified to CB and Nemko safety requirements; developers do not need to perform a separate safety test on the X-capacitor discharge circuit of the power supply.