Datasheet TBU-RS (Bourns) - 2
| Manufacturer | Bourns |
| Description | TBU-RSxxx-300-WH - TBU High-Speed Protector |
| Pages / Page | 9 / 2 — TBU-RSxxx-300-WH Series - TBU® High-Speed Protector. Device Description. … |
| File Format / Size | PDF / 682 Kb |
| Document Language | English |
TBU-RSxxx-300-WH Series - TBU® High-Speed Protector. Device Description. Device Operation
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TBU-RSxxx-300-WH Series - TBU® High-Speed Protector Device Description
TBU-RSxxx-300-WH TBU #2 PHY 7 5 TVS B DIODE RO PRIMARY 4 RE PROTECTOR A DI LINE IN 1 3 DE CONNECTOR TBU #1 RS-485 interfaces are popular in industrial and communication applications due to their high immunity to noise. However, RS-485 interface PHYs are subject to damage by threats such as inductive transients, environmental, and lightning surges commonly found in industrial and communication installations. These threats must be taken into consideration in the design stage of the RS-485 link. Bourns® TBU-RSxxx-300 is a highly integrated and fast RS-485 interface protector that can be used with external overvoltage devices like a GDT or thyristor to deliver IEC 61000-4-5 Class 4 protection. As shown in the above figure, the device integrates two TBU® HSPs (click here for more information on TBU® HSPs) and a pair of TVS diodes to provide a total RS-485 interface protection solution in a small footprint.
Device Operation
In normal operation, the TBU-RSxxx-300 device’s TBU® HSP exhibits low impedance and the TVS Diode exhibits high impedance which has a minimal impact on circuit operation. When a surge is detected at the RS-485 interface and the surge voltage is above the breakdown voltage (VBR) of the TVS Diode, the device’s TVS diode will break down, protecting the RS-485 PHY interface by providing a low impedance path to ground. As the surge current increases above the TBU® HSP’s trigger current level (Itrigger), the TBU® HSP will turn off immediately, thereby blocking the surge energy in less than 1 μs (typical). During the remainder of the surge, the TBU- RSxxx-300 device remains in the protected blocking state, consuming low quiescent current (IQ, 0.5 mA). The device will start its reset process at the end of a surge event; the TBU® HSP will begin the reset process when the voltage across the device drops below the Vreset level and will complete the reset process when the signal line returns to its normal operating range. Specifications are subject to change without notice. Users should verify actual device performance in their specific applications. The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
TBU-RSxxx-300-WH TBU #2 PHY 7 5 TVS B DIODE RO PRIMARY 4 RE PROTECTOR A DI LINE IN 1 3 DE CONNECTOR TBU #1 RS-485 interfaces are popular in industrial and communication applications due to their high immunity to noise. However, RS-485 interface PHYs are subject to damage by threats such as inductive transients, environmental, and lightning surges commonly found in industrial and communication installations. These threats must be taken into consideration in the design stage of the RS-485 link. Bourns® TBU-RSxxx-300 is a highly integrated and fast RS-485 interface protector that can be used with external overvoltage devices like a GDT or thyristor to deliver IEC 61000-4-5 Class 4 protection. As shown in the above figure, the device integrates two TBU® HSPs (click here for more information on TBU® HSPs) and a pair of TVS diodes to provide a total RS-485 interface protection solution in a small footprint.
Device Operation
In normal operation, the TBU-RSxxx-300 device’s TBU® HSP exhibits low impedance and the TVS Diode exhibits high impedance which has a minimal impact on circuit operation. When a surge is detected at the RS-485 interface and the surge voltage is above the breakdown voltage (VBR) of the TVS Diode, the device’s TVS diode will break down, protecting the RS-485 PHY interface by providing a low impedance path to ground. As the surge current increases above the TBU® HSP’s trigger current level (Itrigger), the TBU® HSP will turn off immediately, thereby blocking the surge energy in less than 1 μs (typical). During the remainder of the surge, the TBU- RSxxx-300 device remains in the protected blocking state, consuming low quiescent current (IQ, 0.5 mA). The device will start its reset process at the end of a surge event; the TBU® HSP will begin the reset process when the voltage across the device drops below the Vreset level and will complete the reset process when the signal line returns to its normal operating range. Specifications are subject to change without notice. Users should verify actual device performance in their specific applications. The products described herein and this document are subject to specific legal disclaimers as set forth on the last page of this document, and at www.bourns.com/docs/legal/disclaimer.pdf.
