RS-485EVALBOARD3 Bourns

RS-485 Port Protection Evaluation Board 3 Introduction This evaluation board serves as an aid in J1 J2 evaluating circuit protection on RS-485 serial GND device port solutions using Bourns TBU GND TBU HSP 1 MOV1 GDT1 GDT3 TISP1 High-Speed Protectors (HSPs), FLAT Gas A Discharge Tube (GDT) Surge Arrestors and TVS1 A GDT5 TVS3 Transient Voltage Suppressor (TVS) products TVS2 designed to meet the required industry B standards on RS-485 port interfaces. The B MOV2 GDT2 GDT4 TISP2 TBU HSP 2 recommended Bourns TBU HSP solution GND oerff s enhanced performance features over GND competing technologies, which can help Figure 1 RS-485 Evaluation Board 3 Schematic the design engineer to increase the surge and transient protection level on RS-485 ports, placing the entire circuit protection solution into a smaller PCB area. Bourns has developed an RS-485 evaluation board (measuring 53.5 mm x 25.3 mm x 0.85 mm) manufactured using an FR4 PCB with nickel gold plating on the top and bottom sides. How to Connect the Evaluation Board for Test Set-up Connect J1A and J1B to the exposed lines. Connect J2A and J2B to the Figure 2 RS-485 Evaluation Board 3 Top Side Layout* RS-485 IC device. *The default congfi uration of this board uses two GDTs w/ Table 1 RS-485 Evaluation Board 3 Bill of Materials FLAT technology (GDT3 and GDT4) and one TVS diode (TVS3). The board allows dierff ent congfi urations: Two Model 2017 GDTs w/FLAT technology (GDT3 No. Part Number Qty. Description Reference and GDT4) may be replaced by a) two MOVs (MOV1 and MOV2) or b) two Model 2031 GDTs 1 TBU-CA085-300-WH 2 TBU Single Bidirectional Line 850 V 300 mA TBU HSP 1, TBU HSP 2 (GDT1 and GDT2) or c) two SMD package TISP devices (TISP1 and TISP2) or d) a dual line Model 2 2017-09-SMH-RPLF 2 GDT w/FLAT Technology 90 V GDT3, GDT4 2030 GDT (GDT5). One SOT23 TVS diode (TVS3) may be replaced 3 CDSOT23-SM712 1 Dual Bidirectional Line TVS 12 V SOT23 TVS1, TVS2 with two SMB TVS diodes (TVS1, TVS2). 9/17 K1701RS-485 Port Protection Evaluation Board 3 Performance Graphs RS-485 Port Protection Evaluation Board 3 TBU-CA085-300-WH 80 CDSOT23-SM712RS-485 Interface Line 1 2017-09-SMH-RPLF TBU-CA085-300-WH 2017-09-SMH-RPLF Line 2 80 Surge Generator 1.2/50 s, 2 kV Figure 3 RS-485 Port Protection Reference For more information on implementing advanced circuit protection technologies for RS-485 ports, please review Bourns RS-485 Protection Solution: