Raychems's latest Zener diode micro-assembly protects DC power ports and downstream electronics

The new PolyZen device helps provide coordinated protection with a component that protects like a Zener diode, but is capable of withstanding very high power fault conditions. The PolyZen micro-assembly incorporates a stable Zener diode for precise voltage clamping and a resistively non-linear, polymer positive temperature coefficient (PPTC) layer that responds to either diode heating or overcurrent events by transitioning from a low to high resistance state.

The RoHS-compliant device offers power handling on an order of 100 watts in a 4mm package and helps provide DC power port protection for portable electronics and systems using barrel jacks for power input, as well as internal overvoltage protection and transient suppression.

PolyZen devices help provide resettable protection against multi-watt fault events and requires only 0.7W power dissipation. In the event of sustained high power conditions, the PPTC element of the device "trips" to limit current and generate voltage drop. This functionality helps protect both the Zener and the follow-on electronics, effectively increasing the diode's power handling capacity. Benefits of this innovative solution include:

"The PolyZen device's resettable functionality and its ability to withstand high current inrush make it suitable for portable electronics and other low-power DC devices," said Adrian Mikolajczak, new platform and technology marketing manager for Raychem Circuit Protection. "In addition to extended performance range and survivability, integrated device construction reduces heat sinking requirements and streamlines circuit design."

PolyZen devices are compatible with industry standard installation procedures, and are available in tape and reel packaging for compatibility with high-volume manufacturing.