May 18, 2017
Littelfuse, Inc. has introduced the PolySwitch® LoRho Series SMD PPTC that provides protection for charging cables and connectors from heat generated due to faults within the cable connector or port. As connector sizes get smaller, so does pin-to-pin spacing, which increases the chance that dirt, dust, water and other debris will collect between the pins, and cause an electrical fault. Such faults can generate high levels of heat, which can damage charging cables and the devices being charged, as well as injure users.
However, when a LoRho Series PPTC is placed on the connector’s Vbus line, the device will sense the temperature rise and stop the charging process until the contamination is removed. Once the fault is corrected, the device automatically resets.
Typical applications for the LoRho Series SMD PPTCs include protecting charging cables and connectors with a small pin pitch (pin-to-pin dimensions), such as microUSB and USB-C. This is especially important in fast-charging applications that use higher voltages and currents, such as smartphones, tablets and laptop computers, TVs and set-top boxes, cameras, and video game consoles.
“The LoRho Series SMD PPTC offers an advantage over devices that offer only overcurrent protection because not all faults result in a higher current. Having both overcurrent and overtemperature protection is critically important to safeguarding users of charging cables,” said Vincent Wu, global product manager at Littelfuse. “Never before has this low resistance, compact size, voltage level, overcurrent and overtemperature protection, and resettability been combined in a single device.”
LoRho Series SMD PPTCs offer these key benefits: Surface mount design is compatible with reflow soldering processes, which allows for reduced assembly time and cost vs. leaded and strapped devices. Compact 1206- and 1210-size packages save printed circuit board space at the USB-C connector and ensure the USB-C plug meets USB-IF dimension specifications. Well-suited for use in fast-charging applications up to 12Vdc and 4.5A Ihold.
Availability LoRho Series SMD PPTCs are available in 1206- and 1210-size surface mount packages in tape and reel format in quantities of 15,000. Sample requests may be placed through authorized Littelfuse distributors worldwide.