Multilayer ferrites with in-rush current capability

Transcription

1 Multilayer ferrites with in-rush current capability Alex Snijder Field Application Engineer Wurth Elektronik Nederland BV

2 AGENDA SMT chip bead ferrites Impedance Application CBF CBF HF MPSB Power line application Electrical parameter In Rush Current Tools REDEXPERT SUKW PBF PF 2

3 Attenuation vs Impedance Level [dbµv/m] 60 50? M 40M 50M 70M 100M 200M 300M 400M 600M 1G Frequency [Hz] 3

4 Attenuation vs Impedance Z A Z F U 1 U 2 Z B Source Coupling way Load System attenuation A Z + Z + Z = 20 log A F B Z + Z A B in (db) 4

5 Practical values 1 Ω 10 Ω >90 Ω 5

6 Attenuation vs Impedance 1. 1.Require 20dB of attenuation between 100 and 200 MHz 2. Know that it is a power cable Attenuation (db) 3. Power port has 10 Ω impedance Result is a minimum impedance of 180Ω 180 Impedance of ferrite (Ω) 6

7 Multilayer ferrite bead : Internal Structure - SMD-Ferrites are inductive components for pcb solutions in multilayer technology - They are covered with NiZn and consist of a silver coil inside 7

8 CBF series SMD Ferrites TMSB CBF CBF HF MPSB High Current InRsuh Specified High Current High Speed Wide Band High Current High Speed Wide Band Wide Band 8

9 Power Line Ferrite CBF High Current CBF high Current : Ferrite with current higher 1A For power Line (CBF, MPSB ) the Rated Current is defined for 40K 9

10 Effect of current and Temperature Pulse peak after switch on 10

11 In-Rush Current Multilayer Ferrite (0805) Destruction at a pulse of 1ms with max. 40A pulse current 11

12 INRUSH Currents : Simulations 36 A! - When the capacitor is charged, the current is only limited by the DCR or the source, the ferrite and the capacitor!! 3 A Current nominal! ti=1ms 12

13 CBF Rated Current 13

14 How to protect ferrite SMD/Ferrite U in + DC e.g. 12V DC DC Protect ferrite from In Rush current during : Power up Hot plugging Line Transient Surge Load dump Safety for SMD ferrite against In-Rush current (load dump) current 14

15 WE-MPSB Multilayer Power Suppression Bead High pulse peak possible caused of special internal layer design Size

16 WE-MPSB Multilayer Power Suppression Bead 16

17 WE-MPSB Multilayer Power Suppression Bead Current Load Measurments : 17

18 WE-MPSB T-n-t Triangle Peak Current Capability of the MPSB Series: Pulse length t [ms] Repetition of the pulse n Ambient temperature T [ C] Pulse-Pause p [s] T 25 C, 80 C, 125 C p 1s, 2.5s, 5s For each pulse-pause you have a different triangle with the influences of the parameters T-n-t I [A] 0.5ms, 1ms, 2ms, 4ms, 6ms, 8ms t n 1, 10, 100, 1k, 10k, 100k 18

19 MPSB Rated Current 19

20 Overview EMC Ferrites WE-STAR-FIX WE-STAR-BUENO WE-SFA WE-FLAT WE-RIB WE-UKW WE-AFB / WE-TOF WE-MLS WE-PBF WE-WAFB WE-CMS WE-CBF / WE-MPSB WE-PF WE-SUKW All rights reserved by Wurth Electronics, also in the event of industrial property rights. All rights of disposal such as copying and redistribution rights with us. 20

21 See this example live

22 Thank you for your attention Alex Snijder Field Application Engineer +31 (0)