The rapidly expanding market for ultra-thin portable electronic devices such as media tablets and ultra-thin PCs has created demand for very thin, low-profile, light-weight and high-capacity Lithium Polymer (LiP) and prismatic cells.
A new MHP (Metal Hybrid PPTC) device, the MHP-TA, offers a 9VDC rating and a higher current rating than typical battery strap devices to meet the battery safety requirements of higher-capacity LiP and prismatic batteries found in the latest tablet and ultra-thin computing products. Hybrid MHP technology connects a bimetal protector in parallel with a PPTC (polymeric positive temperature coefficient) device. The resulting MHP-TA device helps provide resettable overtemperature protection, while utilizing the PPTC device to act as a heater and to help keep the bimetal latched until the fault is removed.
APPLICATIONS
• Battery cell protection for high-capacity Lithium Polymer and prismatic cells used in:
- Media tablets
- Ultra-thin notebook PCs
- E-readers
BENEFITS
- Capable of handling the higher voltages and battery discharge rates found in highcapacity LiP and prismatic cell applications.
- Provides resettable overtemperature protection in high-capacity LiP and prismatic cell applications.
DESIGN CONCEPT
In normal operation, current passes through the bimetal contact due to its low contact resistance. During an abnormal event, the device reacts to the rise in cell temperature causing the bimetal contact to open at the specified temperature and its contact resistance to increase.