jor advantage of the USB 3.0 specification is the increased operating current it allows devices to consume (900mA vs 500mA in USB 2.0). As more and more mobile devices adopt the USB port as the primary charging interface, the need for higher charging current has increased, and shorter charge time has become an important consideration. Mobile devices are not always charging when connected to the USB port; in fact, they may spend the majority of time in the Standby or Suspend Mode. A device's Suspend Mode power-consumption characteristic can be a major circuit protection design issue. A USB device designed to support Suspend Mode operation is limited to 2.5mA average current draw. Any circuit protection solution, CMOS or other, must operate within this boundary.
PolyZen devices are polymer-enhanced Zener diodes that help provide coordinated protection against damage caused by overvoltage, overcurrent and ESD transients in a single package. The new PolyZen ZEN059V130A24LS device combines high power-absorption capabilities with low Vz (Zener voltage) and low power-consumption. Due to the device's polymer thermal-protection architecture, it is able to absorb high-energy pulses and effectively block overvoltage and reverse bias sources that could ultimately damage a stand-alone Zener diode. With a Vz below 6 volts, it helps protect sensitive downstream electronics, and its low 5V power consumption meets USB 3.0 Suspend Mode requirements.
For USB 3.0 devices, the PolyZen device can be placed on the USB input port, the Powered-B plug, and/or, where applicable, any supplementary power port.The PolyZen device offers designers the simplicity of a high-power clamping diode while obviating the need for significant heat sinking. Its embedded time delayed overvoltage lockout and overcurrent switching help protect against the use of improper power supplies, reverse bias sources and negative voltages as well as damage caused by overcurrent conditions, ESD transients, inductive spikes and other overvoltage events. It can also help manufacturers reduce warranty costs and improve the reliability of portable electronics such as:
• Mobile Phones and Handhelds
• Personal Navigation Devices (PNDs)
• MP3 and CD Players
• DVD and Blu-Ray Disc Players
• Digital Still Cameras and Video Camcorders
• USB 3.0 Hubs and Adapter Cards
• Printers and Scanners
• Solid-State Devices (SSDs)
• External Hard Disk Drives (HDDs) and Mass Storage Devices
• Laptop and Desktop PCs
The PolyZen ZEN059V130A24LS device helps reduce design cost with single component placement, said Kedar Bhatawadekar, Technical Marketing and Product Application Engineer. Its low power-consumption specifically meets the USB 3.0 leakage current during Suspend Mode requirements, and its small form factor accommodates the continuing miniaturization demands of the electronics industry.