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Shenzhen JDT Fuse Industrial Co.,Ltd
Phone : 0755-8830-8258
Postcode : 518129
E-Mail : andyzheng@jdtfuse.com
URL : http://www.joincircuit.com/
JDT Fuse in USB3.0 applications
Latest USB3.0 protocol ( or "SuperSpeed USB") was developed to provide higher data transfer rates , and through support for each port on the higher current levels to improve supply capacity . It includes new power management features, and is backwards compatible with USB2.0 devices new cables and connectors. The most significant change is that additional copper 4 parallel data lines are added to the existing USB2.0 bus ( as shown). These additional data lines are used to transfer the copper high-speed data transfer but also other harmful ESD and transient voltage .
USB3.0 increased current and power supply capacity implies the need for new circuit protection programs. An improved method of circuit protection can help protect USB3.0 applications from over current, over temperature and voltage transients caused by ESD damage.
Overcurrent protection :
USB3.0 provide power through two components : a standard Host (A type connector ) and a new type of power supply equipment (Powered-B connector ) . Latest SuperSpeed specification can increase the amount of current supplied to the USB device ( increased from 0.5A to 0.9A). The new Powered-B connector allows a USB device up to 1.0A of current to charge another device . Due to an overcurrent condition will affect the power bus , all power ( such as hosts, hubs, and Powered-B devices ) must provide overcurrent protection. UL60950 overcurrent protection is also required by the standard .
Similarly with USB2.0 , USB3.0 host all types of power must be supplied . USB3.0 single unit load weight is defined as 150mA, 100mA than the USB2.0 slight increase . Now, a per-port USB3.0 host must be able to support up to six units (900mA). In addition , USB3.0 bus-powered hubs may no longer need it. All USB3.0 Hub must now be able to support each port 900mA of current.
In addition , support for USB charging and USB3.0 systems need to be able to withstand higher current overcurrent protective device . USB charger with USB2.0 specification uses the same pin configuration, but allows higher currents ( per port up to 1.5A).
Finally , USB3.0 defines a new connector Powered-B , the main advantage of a better portability. Powered-B connector allows to remove the USB cable and additional power . Use Powered-B connector USB devices can now be powered by another USB device . By providing two additional connection socket , the new connector enables a power supply ( with a Powered-B connector socket ) capable to another device ( with a B-type power connector plug ) provides up to 1000mA current. For example , a printer can give a wireless adapter power supply , eliminating the need for a wired USB connection.
In all these applications, polymer positive temperature coefficient device (PPTC) for the USB overcurrent protection provides the most cost-effective solutions . PPTC devices can be used USB3.0 host applications , USB3.0 hub applications, USB charger applications, and USB3.0 Powered-B connector applications current limiting protection. The USB port VBUS power installed PPTC PolySwitch devices are available in short-circuit current limiting to prevent short circuit caused due to sudden downstream circuit overcurrent damage and to help achieve UL60950 standards.
PPTC overcurrent protection devices help designers meet the USB 3.0 specification new high-current requirements and provide a simple, space-saving solution for current limiting .
JDT Fuse PPTC overcurrent, overtemperature protection features in the infrared cameras, speed dome and other security monitoring equipment in a timely and effective to prevent accidental high voltage high current, partial short, crosstalk over current, over temperature and other damage to the equipment , because of the timely protection and self-recovery characteristics, reduce production and maintenance costs, so that monitoring equipment complies with UL, 3C, TUV, GB series safety test requirements.