Aluminum Electrolytic vs. Aluminum Polymer Capacitor

Transcription

1 Aluminum Electrolytic vs. Aluminum Polymer Capacitor APEC 2018 in San Antonio Industry Session Frank Puhane Technical Engineering Team leader

2 Short Introduction of Today s Presenter Frank Puhane Technical Project Engineer & Team Leader Technical Engineering eicap Capacitor Division Background: frank.puhane@we-online.com More than 10 years of work experience in electronics industry Background in Electronics, Power Supply Development and formerly worked as Field Application Engineer In charge for technical product services and application support of capacitor division at WE 2

3 Agenda Overview about Technologies Influence of Input Capacitor Influence of Output Capacitor 3

4 OVERVIEW ABOUT TECHNOLOGIES 4

5 Overview of Electrolytic Capacitors Differentiation of electrolytic capacitors: 5

6 Construction of Aluminum Electrolytic Capacitor Stitching Aluminum Foil (roughened) Anode Separator Paper Aluminum Foil - Cathode Sealing Lead Wire Wet element (with electrolyte) Aluminum case 6

7 Construction of Aluminum Polymer Capacitor Pretreated anode foil Separator Rubber Cathode foil Case Stitched pins 7 7

8 INFLUENCE OF THE INPUT CAPACITOR FOR A BUCK CONVERTER 8

9 Influence of the Input Capacitor for a Buck Converter Input voltage U in = 12V Output voltage U out = 5V Load current 1A (ohmic load) Frequency f switch = 1MHz Monolithic synchronous converter Molded power Inductor Input filter 9

10 Measurement of Conducted Emission Measurement equipment R&S ESRP 3 EMI Test Receiver LISN => ENV216 Two-Line V-Network Measurement in a shielded room 10

11 Conducted Emission Measurement 1 No input filter Input capacitor: WCAP-ASLL => 47µF / 16V => ESR = 411mR / ESL = 19nH (REDEXPERT: ) 11

12 Conducted Emission Root Cause Symmetrical voltage at the input is: u sup t i t R u t i t R i t R u t in sup in in sup C,in eq,c C, in ESR and ESL should be as small as possible Possible resonance by L sup, L eq,c and C in 12

13 Conducted Emission Measurement 2 No input filter, WCAP-PSLP => 47µF / 16V => ESR = 20,7mR / ESL = 3,9nH (REDEXPERT:

14 EMC Action Input Filter Definition of input filter π-filter with secondary stage inductor MLCC -> WCAP-CSGP Ferrite -> WE-CBF Inductor -> WE-LQS 14

15 Conducted Emission Measurement 4 Input filter plus input capacitor => WCAP-ASLL

16 Conducted Emission Measurement 5 Input filter plus input capacitor => WCAP-PSLP

17 INFLUENCE OF THE OUTPUT CAPACITOR FOR A BUCK CONVERTER 17

18 Influence of the Output Capacitor for a Buck Converter Input voltage U in = 12V Output voltage U out = 5V Load current 1A (ohmic load) Frequency f switch = 1MHz Monolithic synchronous converter Molded power Inductor Input filter 18

19 Influence of the Output Capacitor for a Buck Converter Output capacitor => WCAP-ASLL => 47µF / 16V; ESR = 411mR / ESL = 19nH 200mV -200mV 19

20 Output Voltage Ripple Root Cause The symmetrical voltage at the output is: u out t i t R u t C,out eq,c C, out ESR as small as possible Possible differential resonances due to parasitic of the component 20

21 Influence of the Output Capacitor for a Buck Converter Output capacitor => WCAP-PSLP => 47µF / 16V; ESR = 20,7mR / ESL = 3,9nH 20mV -30mV 21

22 Influence of the Output Capacitor for a Buck Converter Output capacitor => WCAP-PSLP and WCAP-CSGP 20mV 10mV -20mV -10mV 22

23 Conclusion Application Aluminum Electrolytic Aluminum Solid Polymer Filter DC-DC Converter Battery powered appl. Low / green energy Low temperature High temperature Audio Higher vibration 23

24 Thanks for your attention! 24