SMD1812-350 6V3.5ASurface Mount PolySwitch PTC Devices SMD Resettable Fuse PPTC

Description

The 1812 series provides su-ace mount resettable overcurrent protection with

holding current from 0.1A to 9.0A. This series offers complete portfolio in terms of

holding current and working voltage, and is suitable for wide range of application.

Features

Applications

Electrical Characteristics

Note on Electrical Characteristics

■ Vocabulary

·I_hold = Hold current: maximum current device will pass without tripping in 23℃ still air.

·I_trip = Trip current: minimum current at which the device will trip in 23℃ still air.

·V_max = Maximum voltage device can withstand without damage at rated current (I_max)

·I_max = Maximum fault current device can withstand without damage at rated voltage (V_max)

·P_{d typ.} = Typical power dissipated from device when in the tripped state at 23℃ still air.

·R_min = Minimum resistance of device in initial (un-soldered) state.

·R_1max = Maximum resistance of device at 23℃ measured one hour after tripping or reflow soldering of 260℃ for 20 sec.

■ Value specified is determined by using the PWB with 0.030”*1.5oz copper traces.

■ Caution: Operation beyond the specified rating may result in damage and possible arcing and flame.

■ Specifications are subject to change without notice.

Polymeric PTC Selecting Guide

■ Determine the following operating parameters for the circuits:

■ Select the device from factor and dimension suitable for the application

■ Compare the maximum rating for V_max and I_max of the PPTC device with the circuit in application and make sure

the circuit’s requirement does not exceed the device rating.

■ Check that PPTC device’s trip time (time-to-trip) will protect the circuit.

■ Verify that the circuit operating temperature is within the PPTC device’s normal operating temperature range.

■ Verify that pe-ormance and suitability of the chosen PPTC device in the application.

WARNING

■ Mechanical Stress

·PPTC devices will undergo a thermal expansion during fault condition. If PPTC devices are installed or placed in an application

where the space between PPTC devices and the surrounding materials (e.g., covering materials, packaging materials, encapsulate

materials and the like) is insufficient, it will cause an inhibiting effect upon the thermal expansion. Pressing, twisting, bending and

other kinds of mechanical stress will also adversely affect the pe-ormance of the PPTC devices, and shall not be used or applied.

■ Chemical Pollutants

·Silicone-based oils, oils, solvents, gels, electrolytes, fuels, acids, and the like will adversely affect the properties of PPTC devices,

and shall not be used or applied.

■ Electronic and Thermal Effect

·PPTC devices are secondary protection devices and are used solely for sporadic, accidental over-current or over-temperature

error condition, and shall NOT be used if or when constant or repeated fault conditions (such fault conditions may be caused by,

among others, incorrect pin-connection of a connector) or over-extensive trip events may occur.

·PPTC devices are different from fuses and, when a fault condition occurs, will go into high-resistance state and do not open

circuit, in which case the voltage at such PPTC devices may reach a hazardous level.

·Operation over the maximum rating or other forms of improper use may cause failure, arcing, flame and/or other damage to

the PPTC devices.

·Conductive material contamination, such as metal particle, may induce shortage, flame or arcing.

·Due to the inductance, the operation circuits may generate a circuit voltage (Ldi/dt) above the rated voltage of PPTC devices,

which shall not be used under such circumstances.

■ General

·Customers shall evaluate and test the properties of PPTC devices independently to verify and ensure that their individual

applications will be met.

·The pe-ormance of PPTC devices will be adversely affected if they are improperly used under electronic, thermal and/or

mechanical procedures and/or conditions non-conformant to those recommended by manufacturer.

·Customers shall be responsible for determining whether it is necessary to have back-up, failsafe and/or fool-proof protection

To avoid or minimize damage that may result from extra-ordinary, irregular function or failure of PPTC devices.

·Any and all responsibilities and liabilities are disclaimed if any item under this notice of warning is not complied with.

Thermal Derating Chart

Recommended Hold Current (A) at Ambient Temperature (℃)

Yantai Rongfan Electronics Technology Co., Ltd.(XinruiElectronics Technology) is an innovative high-tech enterprise that integrates research and development, production, sales, and services. The company specializes in the production and sales of protection products for current, voltage, temperature, and other aspects. Its products have obtained multiple certifications such as SGS, UL, and TUV. The company has a production base for PPTC resettable fuses, one-time fuses, and thermistors, with an annual output of nearly 100 million units. It is also capable of designing and developing special products according to customer's requirements. The company has established production bases in Shandong and Guangdong, where it conducts research and development and production of current and temperature protection devices. The company's products are widely used in various industries such as communication, computers, security monitoring, household appliances, automotive digital, toys, power supplies, chargers, control boards, motors, and batteries. In order to meet the higher requirements for product research and design from different customers, the company has reached consensus with many well-known brands in the industry. It has established cooperative relationships with high-quality enterprises such as Littelfuse in the United States, Polytronics in Taiwan, and domestic manufacturers of varistors, thermal fuses, and temperature controllers. The company promotes and sells its main products, while also improving its own product technology to achieve mutual progress and development. The company adheres to the concept of customer first and quality first, and follows a high-quality route of continuous improvement. With innovative product design and rigorous work style, the company strives to create the best products and has won unanimous praise from domestic and foreign customers. It has now become an expert in protecting power supplies, circuits, and various electronic components, and is committed to building an international brand for the industry's future.