Product Overview
Metal Hybrid PPTC (MHP) Devices
Resettable circuit protection for high-rate-discharge li-ion battery applications such as
cordless power tools, e-bikes and back-up power supplies.TE Connectivity Metal Hybrid PPTC (MHP) Devices
The rapidly expanding market for high-rate-discharge lithium ion (Li-ion) batteries used in
applications such as cordless power tools, e-bikes and back-up power supplies has created
the need for cost-effective circuit protection devices capable of providing 30A+ hold
currents at voltage ratings over 30V . To meet this need, a new hybrid device has been
DC
developed that connects a bimetal protector in parallel with a PPTC (polymeric positive
temperature coefficient) device. The resulting Metal Hybrid PPTC (MHP) device helps
provide resettable overcurrent protection while also utilizing the low resistance of the PPTC
device to help prevent arcing in the bimetal protector at higher currents.
APPLICATIONS
Li-ion battery packs for high-rate-discharge applications
- Cordless power tools
- E-bikes
- Back-up power supplies (UPS)
- Medical Devices
Motor protection
KEY FEATURES
30A hold current
BENEFITS
Rated at 36V , 100A max.
DC Fills market need for battery protection devices rated above 30A and 30V
DC
Provides resettable overcurrent and short circuit protection in Li-ion batteries
Low device resistance (< 2mOhm)
Helps protect Li-ion cells from damage from abnormal high currents that could cause
compared to other breaker devices
heat damage and lead to premature cell end of life and potential field returns
Arc suppression: Current shunts to the PPTC due to its low resistance helping to
Able to withstand heavy vibration
suppress arcing all while helping protect the contacts from damage or welding shut
and impact
Double make/double break contact design allows for a high current rating in a smaller
device package
Device allows easy mounting
between 18650 cells
DESIGN CONCEPT
In normal operation, current passes through the bimetal contact due to its low contact
resistance. During an abnormal event, such as a power tool rotor lock, higher current is
generated in the circuit causing the bimetal contact to open and its contact resistance to
increase. At this point, the current shunts to the lower resistance PPTC device which helps
prevent arcing between the contacts while also heating the bimetal, keeping it open and
in a latched position. This integrated design addresses the need for compact, resettable
overcurrent protection devices capable of arc suppression in high current DC power
applications.
Bimetal
PPTC Device
Leakage Current
1. Normal operation 2. Contact pressure decreases 3. Holds under
Contact resistance Contact resistance increases abnormal condition
< Contact arc resistance
PPTC resistance
PPTC resistance
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