TE Circuit Protection introduces MHP-TA resettable TCO devices



Thermal protection for LiP battery cells in ultra-thin portable electronics

Designers are increasingly turning to high-capacity, envelope-like LiP (Lithium Polymer) cells to optimize space use in media tablets, ultra-thin PCs, electronic readers, and other small, slim consumer electronics. At the same time, battery manufacturers have been challenged to find ultra-compact over-temperature protection devices that can meet the higher currents typically found in these applications. In response, TE Circuit Protection has introduced the MHP-TA series of ultra-low-profile (5.8 x 3.75 x 1.15 mm) resettable TCO (thermal cut-off) devices for lithium battery protection. The MHP-TA series of devices features a 9 V DC rating, two product categories with different current-carrying capacities, and multiple cut-off temperature ratings. The MHP-TA series is an extension of TE Circuit Protection's MHP (Metal Hybrid PPTC) which connects a bimetal protector in parallel with a PPTC (polymeric positive temperature coefficient) device. The initial MHP30-36 and MHP-SA series, targeted higher-current (above 30 A, 30 V DC) Li-ion battery pack applications used in portable power tools and energy storage systems.?? The new MHP-TA series is for applications with lower voltage and current ratings.  As a result, TE Circuit Protection was able to downsize the MHP product to offer an ultra-compact device that meets the space requirements of the growing LiP market. In battery cell designs, the MHP-TA series helps provide resettable over-temperature protection, while utilizing the PPTC to act as a heater and to keep the bimetal latched until the fault is removed.??"To keep pace with the ongoing trend toward miniaturization in consumer electronics, battery designers are increasingly using LiP cells in the thinnest products hitting the market," said Ty Bowman, Strategic Marketing Manager for TE Circuit protection. "But at the same time, these designers have been faced with limited options for providing over-temperature protection in high-capacity lithium polymer cell designs. With the introduction of the MHP-TA series they now have an ultra-compact, resettable, and high-performance alternative."?? The MHP-TA series comprises nine devices with two levels of current carrying capacity:  low-current MHP-TA6-9 products with an approximately 6 A hold current @ 25 °C, and high-current MHP-TA15-9 products providing a hold current of approximately 15 A. The low-current MHP-TA6-9 devices are available in four different temperature ratings (72, 77, 82, and 85 °C) and the high-current MHP-TA15 devices in five temperature ratings (72, 77, 82, 85, and 90 °C) TE Circuit Protection