Resettable PPTC Devices feature overcurrent protection.

Press Release Summary:

Available in PolySwitch ASMDC, femtoASMD, and picoASMD Series models, Resettable PPTC Devices are suitable in automotive infotainment, communications, network, security, ADAS and climate control systems. Offering wide range of form factors, femtoASMD, and picoASMD Series come in smaller footprint. Protecting against overcurrents and short circuits, units does not require replacement after fault occurance. Units meet AEC-Q200 and ISO/TS16949 standards.

Original Press Release:

Littelfuse Introduces Three New Series of PolySwitch AEC-Q200 Qualified Resettable PPTC Devices for Automotive Applications

Surface mount PPTCs with broad holding current and voltage rating ranges enhance design flexibility

Littelfuse, Inc., the global leader in circuit protection, today 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.”

PolySwitch ASMDC, femtoASMD, and picoASMD Series Resettable PPTCs offer these key benefits:

  • Smaller-footprint picoASMD Series and femtoASMD Series devices provide a wider range of form factors to enhance design flexibility.
  • Low-profile ASMDC Series products help circuit designers meet the ever-increasing demand for compact and space-saving designs as the amount of electronics content in vehicles grows.
  • Resettable solutions designed to guard against overcurrents and short circuits in automotive circuitry restore systems to operation after the fault condition is resolved, for greater safety, convenience and protection.
  • AEC-Q200 qualified, ISO/TS16949 certified devices meet the most stringent requirements to withstand harsh automotive environments.


Surface mount PolySwitch ASMDC, femtoASMD, and picoASMD Series Resettable PPTCs are available in tape and reel packaging in quantities of 4,000 or 3,000. Sample requests may be placed through authorized Littelfuse distributors worldwide. For a listing of Littelfuse distributors, please visit

For More Information

Additional information is available on the PolySwitch ASMDC, femtoSMD, and picoASMD Series Resettable PPTC product pages. For technical questions, please contact: Amanda Cheng, assistant product manager, PPTC Devices,

About Littelfuse

Founded in 1927, Littelfuse is the world leader in circuit protection with growing global platforms in power control and sensing. The company serves customers in the electronics, automotive and industrial markets with technologies including fuses, semiconductors, polymers, ceramics, relays and sensors. Littelfuse has over 10,000 employees in more than 40 locations throughout the Americas, Europe and Asia. For more information, please visit

Media Contact:

Rhonda Stratton

Global Marketing Communications Manager

Electronics Products, Littelfuse, Inc.


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