Littelfuse introduced three series of PolySwitch AEC-Q200 qualified resettable Polymeric Positive Temperature Coefficient (PPTC) devices. These surface mount devices are designed for robust overcurrent protection in extremely harsh automotive environments. Unlike fuses, resettable PPTCs do not require replacement after a fault event; they allow the circuit to return to the normal operating condition after the power has been removed and/or the overcurrent condition is eliminated.
The largest of the new devices, the 2920-size ASMDC Series, has a lower profile compared to existing 2920 size ASMD series surface mount PPTCs, and no heavy metal terminals. It also offers the highest holding current and voltage rating of the three. The two smallest of these new devices, the 0603-size femtoASMD Series and the 0805-size picoASMD Series, are ideal for applications in crowded automotive electronics boards.
Typical applications for the ASMDC, femtoASMD, and picoASMD Series Resettable PPTCs include automotive infotainment, communications (GPS navigation), network (CAN Bus, LIN bus), body electronics (door locks, lumbar pumps), security (keyless entry, rearview camera), ADAS (advanced driver assistance system) and climate control systems.
“The choice of compact footprint or low profile packaging combined with AEC-Q200 qualification make these SMD resettable PPTCs ideal for overcurrent and short-circuit protection under the hood,” said Yong Zhang, product manager, PPTC Devices at Littelfuse. “Together, they extend the wide range of form factors, operating currents, and voltage ranges Littelfuse offers, and give automotive electronics designers greater design flexibility.”
