Protection for handheld media against dirty power

Tyco Electronics has released the new PolyZen micro-assemblies which combine a Zener diode for crisp voltage clamping with a resistively non-linear, polymeric Positive Temperature Coefficient (PTC) layer to enhance protection for sensitive low-voltage components.

The advanced PTC layer responds to diode heating or over-current events by transitioning from its low-resistance state to high-resistance. In the event of sustained high-power conditions, the tripped PTC element limits current and generates a voltage drop to help protect both the Zener and the connected electronics. This effectively increases the Zener diode’s power-handling capability.

By combining a PTC element and a Zener diode, Tyco Electronics’ PolyZen technology is especially effective at helping to clamp and smooth inductive voltage spikes. In response to the high potential of an inductive spike, it helps to shunt current to ground until the voltage is reduced to the normal operating range.

In general, the Zener-diode element will protect against damaging voltage transients and allow stable operation from dirty power supplies. In the case where a power supply of incorrect voltage is connected, it will help to clamp the voltage, shunt excess power to ground, and eventually lock-out the erroneous supply.

 

FEATURES Hold currents up to 2.3A Time-delayed, over-voltage trip Time-delayed, reverse-bias trip Power handling on the order of 30 Watts 4mm x 4mm package

APPLICATIONS Bus protection: Media drives Flash-memory USB GPS receivers Consumer and professional handheld devices

 

 

Tyco Electronics / PolyZen device