Welcome to the PolyZen Circuit Protection Solution Product Training Module. Littelfuse recently developed the PolyZen device, a polymer-enhanced, precision Zener diode micro-assembly. In this module we will discuss how the PolyZen solution couples the industry leading Littelfuse polymer positive temperature coefficient or PPTC technology with a precision Zener diode. With the miniaturization trend in portable and desktop electronics it is a necessity to use external power supplies to provide power for normal operation and/or charging. With widespread market availability of external and universal power supplies, the design engineer will be challenged to incorporate additional safeguards against unexpected damage caused by the use of unauthorized power supplies. This training module will show the types of protection this device creates along with the advantages in using it in your next external power supply design.