Electronic Components Datasheet Search |
|
SMT50-130 Datasheet(PDF) 1 Page - Littelfuse |
|
SMT50-130 Datasheet(HTML) 1 Page - Littelfuse |
1 / 3 page 48 www .littelfuse .com SMT50 The electrical characteristics of a SMT50 device are similar to that of a self-gated Triac, but the SMT50 is a two terminal device with no gate. The gate function is achieved by an internal current controlled mechanism. Like the T.V.S. diodes, the SMT50 has a standoff voltage (Vrm) which should be equal to or greater than the operating voltage of the system to be protected. At this voltage (Vrm) the current consumption of the SMT50 is negligible and will not affect the protected system. When a transient occurs, the voltage across the SMT50 will increase until the breakdown voltage (Vbr) is reached. At this point the device will operate in a similar way to a T.V.S. device and is in avalanche mode. The voltage of the transient will now be limited and will only increase by a few volts as the device diverts more current. As this transient current rises, a level of current through the device is reached (Ibo) which causes the device to switch to a fully conductive state such that the voltage across the device is now only a few volts (Vt). The voltage at which the device switched from the avalanche mode to the fully conductive state (Vt) is known as the Breakover voltage (Vbo). When the device is in the Vt state, high currents can be diverted without damage to the SMT50 due to the low voltage across the device, since the limiting factor in such devices is dissipated power (V x I). Resetting of the device to the non-conducting state is controlled by the current flowing through the device. When the current falls below a certain value, known as the Holding Current (Ih), the device resets automatically. As with the avalanche T.V.S. device, if the SMT50 is subjected to a surge current which is beyond its maximum rating, then the device will fail in short circuit mode, ensuring that the equipment is ultimately protected. SELECTING A SMT50 COMPLIES WITH THE PEAK SURGE VOLTAGE CURRENT ADMISSIBLE IPP NECESSARY FOLLOWING STANDARDS VOLTAGE WAVEFORM WAVEFORM RESISTOR (V) ( µS) ( µS) (A) ( Ω) (CCITT) ITU-K20 1000 10/700 5/310 25 - (CCITT) ITU-K17 1500 10/700 5/310 38 - - VDE0433 2000 10/700 5/310 50 VDE0878 2000 1.2/50 1/20 50 - IEC-1000-4-5 10/700 5/310 50 - level 4 level 3 1.2/500 8/20 100 - FCC Part 68, lightning surge 1500 10/160 10/160 75 12.5 type A 800 10/560 10/560 55 6.5 FCC Part 68, lightning surge 1000 9/720 5/320 25 - type B Bellcore TR-NWT-001089 2500 2/10 2/10 150 11.5 first level 1000 10/1000 10/1000 50 10 Bellcore TR-NWT-001089 5000 2/10 2/10 150 11.5 second level CNET I31-24 1000 0.5/700 0.8/310 25 - VR VBR VRM VBO IRM IBO IH Ipp I V 1. When selecting a SMT50 device, it is important that the Vrm of the device is equal to or greater than the the operating voltage of the system. 2. The minimum Holding Current (Ih) must be greater than the current the system is capable of delivering otherwise the device will remain conducting following a transient condition. V-I Graph illustrating symbols and terms for the SMT50 surge protection device. ELECTRICAL CHARACTERISTICS |
Similar Part No. - SMT50-130 |
|
Similar Description - SMT50-130 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |