TE Circuit Protection’s PolyZen ESD Protection Devices are made for USB Applications such as over-voltage protection, fault current protection, reverse voltage protection, and DC power regulation of USB host controller interface circuits of USB powered consumer electronics, external hard disk drives and solid state devices. A unique feature of the PolyZen micro-assembly is that the Zener diode is thermally coupled to a resistively non-linear, polymer PTC (Positive Temperature Coefficient) layer. This PTC layer is fully integrated into the device, and is electrically in series between VIN and the diode clamped VOUT.

ESD Circuit Protection for USB Host Controller Interface

ESD Circuit Protection for USB3.0 Host Controller Interface. Courtesy: TE Circuit Protection

TE Circuit Protection’s PolyZen ESD protection devices are polymer-enhanced, precision Zener diode micro-assemblies. They offer resettable protection against multi-Watt fault events and spare the need for large heavy heat sinks. A unique feature of the PolyZen micro-assembly is that the Zener diode is thermally coupled to a resistively non-linear, polymer PTC (Positive Temperature Coefficient) layer. This PTC layer is fully integrated into the device, and is electrically in series between VIN and the diode clamped VOUT.

This polymer PTC layer responds to either extended diode heating or overcurrent events by transitioning from a low to high resistance state, also known as “tripping”. A tripped PTC will limit current and generate voltage drop. It helps to protect both the Zener diode and the follow-on electronics and effectively increases the diode’s power handling capability. The Zener diode used for voltage clamping in the PolyZen micro-assembly was selected due to its relatively flat voltage vs current response. This helps improve output voltage clamping, even when input voltage is high and diode current is large.

The polymer-enhanced Zener diode helps protect sensitive portable electronics from damage caused by inductive voltage spikes, voltage transients, improper power supplies, nd reverse bias conditions. The PolyZen ZEN059V130A24LS device is particularly useful for USB 2.0/3.0 powered devices; typically, it draws only 500µA of operating current in USB suspend mode.

Key Features of PolyZen ESD Protection Devices

  • Meets USB suspend mode current requirement – 500µA (typ) @ 5.0V
  • Overvoltage transient suppression
  • Stable VZ vs fault current
  • Time delayed, overvoltage trip
  • Time delayed, reverse bias trip
  • Multi-Watt power handling capability
  • Integrated device construction
  • RoHS compliant and halogen free

Applications of PolyZen ESD Protection Devices

  • USB 2.0/3.0 powered consumer electronics, external hard disk drives and solid state devices
  • DC power port protection in systems using barrel jacks for power input
  • DC power port protection in portable electronics and navigation devices
  • DC output voltage regulation
  • USB 3.0 hubs and adapter cards
  • Laptops and desktop PCs