VISHAY Intertechnology, represented in Australia by Braemac , has released a range of components that integrate two positive temperature coefficient (PTC) thermistors into a single surface-mount package.
The Vishay BCcomponents 2322 673 xxxxx twin vertical SMD PTC devices are constructed from a ceramic disc, reflow soldered to a lead-frame. This physical construction results in a flat pick-up area of 30mm2, which facilitates automated assembly.
In addition to reducing component count, they can reduce the board space required to implement overload protection in telecommunications applications by up to 65%. The maximum voltage rating for the devices is 240V and components are available in variants with maximum trip times between 1.2s and 4s and maximum current ratings ranging from 2.5A to 4A.
The components are fully compatible with automated pick-and-place assembly and suitable for use in lead-free soldering processes. They help to reduce assembly time by providing prematched pairs of thermistors within the same package. This eliminates the need for resistance matching.
The use of ceramic PTC technology confers high stability and fast response and recovery. It also provides the ability to sustain several trip cycles. This in turn allows the devices to conform to the more stringent requirements of the ITU K20-21-45 Edition 2003 specification for overvoltage and overcurrent protection for telecommunications equipment.
The devices are rated to function across the industrial temperature range of -40°C to +85°C. Vishay can produce custom versions based on the PTC technology.