PolySwitch devices for telecommunication and networking applications were initially designed over ten years ago to meet the growing demand for resettable overcurrent protection. These product families help provide protection against power cross and power induction surge as defined in ITU, Telcordia, and UL. Available in chip, surface-mount, and radial-leaded configurations, PolySwitch devices help improve the reliability of customer premise and network equipment world wide.
Find out more about the new PolySwitch TSM600-400F designed to meet the new issue 3 of Telcordia GR-1089.
Part Numbering System for Radial-leaded Telecommunications and Networking Devices
Part Numbering System for Surface-mount Telecommunications and Networking Devices
Part Numbering System for Chip Telecommunications and Networking Devices
Agency Recognition for Telecommunications and Networking Devices*
Standard
File Number
UL
E74889
CSA
78165C
TUV
Per IEC60730-1
Note: *For agency recognition information on BBRF and RXEF series, see radial-leaded product page. For SMD, midSMD and miniSMDC series, see surface-mount product page.
Solder Reflow and Rework Recommendations for Telecommunications Surface-mount Devices
Solder Reflow
• Recommended reflow method: IR, vapor phase oven, hot air oven.
• Surface-mount devices are not designed to be wave soldered to the bottom side of the board.
• Recommended maximum paste thickness of 0.25mm (0.010 in).
• Devices can be cleaned using standard industry methods and solvents.
Rework
• If a device is removed from the board, it should be discarded and replaced with a new device.
Wave Soldering and Rework Recommendations for Telecommunications Radial-leaded Devices
Recommended Wave Soldering
• Soldering temperature profile
Temperature characteristic at component terminal with dual wave soldering
Rework
• If a device is removed from the board, it should be discarded and replaced with a new device.
Users should independently evaluate the suitability of and test each product selected for their own application.
Operation beyond the maximum voltage or current ratings or improper use may result in device damage and possible electrical arcing and flame.
These devices are intended for protection against damage caused by occasional overcurrent or overtemperature fault conditions and should not be used when repeated fault conditions or prolonged trip events are anticipated.
Operation in circuits with a large inductance can generate a circuit voltage (L di/dt) above the rated voltage of the PolySwitch resettable device. This product should not be used in an application where the maximum interrupt voltage can be exceeded by inductive spikes.
A PPTC device is not a fuse – it is a nonlinear thermistor that limits current. Under a fault condition all PPTC devices go into a high resistance state but do not open circuit, so hazardous voltage may be present at PPTC locations.
Contamination of the PPTC material with certain silicon-based oils or some aggressive solvents can adversely impact the performance of the devices.
Device performance can be impacted negatively if devices are handled in a manner inconsistent with recommended electronic, thermal, and mechanical procedures for electronic components.
PPTC devices are not recommended for installation in applications where the device is constrained such that its PTC properties are inhibited, for example in rigid potting materials or in rigid housings, which lack adequate clearance to accommodate device expansion.