Tyco Electronics has added to its range of PolyZen polymer enhanced, precision Zener diode micro-assemblies. The new devices feature a higher hold current (2.3A) and are designed to help protect circuits in global positioning systems and other video-based peripherals that can be charged in the car.

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 device is designed to protect like a Zener diode, and is capable of withstanding very high power fault conditions without requiring any special heat sinking structures beyond normal printed circuit board traces.

According to the supplier, by clamping and smoothing inductive voltage spikes, PolyZen devices help shield downstream electronics from overvoltage and reverse bias. Also the high power absorption capability protects against faults that occur when using an incorrect or misconnected power supply.