Electronic Components Datasheet Search |
|
AN1702 Datasheet(PDF) 9 Page - STMicroelectronics |
|
AN1702 Datasheet(HTML) 9 Page - STMicroelectronics |
9 / 11 page AN1702 Transient voltage suppression 9/11 7 Transient voltage suppression Transient voltage surges are generated generally by inductive load switching, for example, the equipment starts and stops, lightning strikes, etc. The standard IEC 61000-4-5 Immunity Test describes a method to test circuits with a waveform simulating these conditions (see Figure 6). Figure 6. IEC 61000-4-5 transient voltage test V and I waveforms Surge voltages inducted on both differential lines do not affect the entire system operation, if the bus is isolated, and the ground voltage shift generated does not exceed the maximum ratings. However, the use of additional transient voltage suppressors (TVS) is advisable, in order to protect against surges in case of miswiring, incorrect grounding and other fault conditions. ST offers a wide range of TVS. Visit the site: http://eu.st.com/stonline/discretes/index.shtml. The selection criteria are the stand-off voltage (VRM), the clamping voltage (VCL) and the peak power dissipation (PD). The stand- off voltage must not exceed the operating common mode voltage range (-7 to +12 V), in order to avoid clamping during the normal operation, while the clamping voltage must be low enough to hold the line voltage with no damage to the protected circuits. The peak power dissipation is the product of the clamping voltage and the peak current that can be managed by the TVS without being harmed. One TVS suitable for a RS-485 network is the ST’s SMA12CA. It has: Equation 2 Figure 7. Usage of the transient voltage suppressors in the RS-485 network V RM= V CL 19.9 V = @ IPEAK 20A; = +/- 12 V; P D 400 W = B |
Similar Part No. - AN1702 |
|
Similar Description - AN1702 |
|
|
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 |