Vicor Corporation · NASDAQ:VICR
Vicor — Technical Presentation (2019)
64 slides from Vicor's technical presentation, 2019
Slide 1: Ferroelectric ceramic capacitors: There is more than meets the eye
Prof. Sam Ben-Yaakov 1 Ferroelectric ceramic capacitors: There is more than meets the eye Presented at:
Slide 2: Resources
Prof. Sam Ben-Yaakov 2 Resources This lecture is recorded and be available at the YouTube channel: https://www.youtube.com/user/sambenyaakov/videos LinkedIn Group ” Where analog and power electronics meet knowledge “ https://www.linkedin.com/groups/13606756 Papers and university lectures http://www.
Slide 3: Background
Prof. Sam Ben-Yaakov 3 Background Ceramic capacitors are one of the most popular electronic devices. They are used for filtering, decoupling and bypass. And yet, not all the features of these devices are understood or even known.
Slide 4: Objective
Prof. Sam Ben-Yaakov 4 Objective To present unfamiliar characteristics of ceramic capacitors (especially ferroelectric type) relevant to power electronics. • For ceramic capacitor types and classification see https://en.wikipedia.org/wiki/Ceramic_capacitor
Slide 5: Outline
Prof. Sam Ben-Yaakov 5 Outline 1. General specifications of commercial ceramic capacitors 2. ESR as a function of bias voltage 3. Piezoelectricity 4. Nonlinear capacitor modeling
Slide 6: General specifications of commercial ceramic capacitors
Prof. Sam Ben-Yaakov 6 General specifications of commercial ceramic capacitors
Slide 7: Structure of ceramic capacitors
Prof. Sam Ben-Yaakov 7 Structure of ceramic capacitors Wikipedia
Slide 8: Commercial Ceramic capacitors
Prof. Sam Ben-Yaakov 8 Commercial Ceramic capacitors • Practical ceramic capacitors are build around paraelectric (Class I) and ferroelectric (Class II,III) dielectric materials • Predominant Class I material is C0G (NPO) – low dielectric constant • Class II, III includes different dielectric materi
Slide 9: Paraelectric - COG (NPO) vs Ferroelectric
Prof. Sam Ben-Yaakov 9 Paraelectric - COG (NPO) Small 𝜀𝑟 , smaller ESR Ferroelectric Large 𝜀𝑟 , larger ESR
Slide 10: Ferroelectricity - Electric polarization
Prof. Sam Ben-Yaakov 10 Feroelectricity - Electric polarization Polarization: a measure of electric dipole moment, ability to bound charge
Slide 11: Electric polarization of dielectric materials
Prof. Sam Ben-Yaakov 11 Electric polarization of dielectric materials Paraelectricity, ferroelectricity Constant dielectric ∝Q ∝V Paraelectric Ferroelectric material Ferroelectric 𝜀𝑟 of ferroelectric material is very large up to 7000 Small capacitors
Slide 12: Ferroelectric hysteresis and capacitance
Prof. Sam Ben-Yaakov 12 Ferroelectric hysteresis and capacitance Charge [Q] 𝑑𝑄 𝐶𝑑 = 𝑑𝑉 Voltage [V]
Slide 13: Commercial paraelectric ceramic capacitors (C0G) limited to about 0.1μF
Prof. Sam Ben-Yaakov 13 Commercial paraelectric ceramic capacitors (C0G) are limited to about 0.1μF
Slide 14: Temperature dependence
Prof. Sam Ben-Yaakov 14 Temperature dependence GOC (NPO) EIA - Electronic Industries Alliance JIS - Japanese Industrial Standards
Slide 15: Typical ceramic capacitor data sheet parameters
Prof. Sam Ben-Yaakov 15 Typical ceramic capacitor data sheet parameters ESR ESL C 𝜔𝐸𝑆𝐿 𝜔𝐸𝐶𝐿 1 1 𝜔0 = 𝑓0 = 𝐿𝐶 2𝜋 𝐿𝐶 𝐸𝑆 𝑓0 At resonance: ESR ESL C ESR 1 𝑓 < 𝑓0 : 𝑍= 𝜔𝐶 𝑓 > 𝑓0 : 𝑍 = 𝜔𝐸𝑆𝐿
Slide 16: Prof. Sam Ben-Yaakov
Prof. Sam Ben-Yaakov 16 2 𝑃 = 𝑖𝑟𝑚𝑠 ∙ 𝐸𝑆 ∆𝑇 = 𝑃 ∙ 𝑡𝑒𝑟𝑚𝑎𝑙
Slide 17: Why 0.1uF in parallel to a larger capacitor?
Prof. Sam Ben-Yaakov 17 Why 0.1uF in parallel to a larger capacitor? 1 1 𝑍 1 1 𝑓10 𝑓0 1
Slide 18: Resonant frequency
Prof. Sam Ben-Yaakov 18 1 1 Resonant 1 𝑍 𝜔𝐿 = frequency 𝜔𝐶 1 𝜔= 𝐿𝐶 1 1 𝑓10 𝑓0 1
Slide 19: Capacitance definition
Prof. Sam Ben-Yaakov 19 Capacitance definition (?) 0.5Vrms Why the peak? 1VAC C VAC C VBIAS 1kHz Local, Small signal, Cd Large signal Cac
Slide 20: The effect of size on C=f(Vbias)
Prof. Sam Ben-Yaakov 20 (No endorsement/affiliation implied) The effect of size on C=f(Vbias)
Slide 21: The effect of size
Prof. Sam Ben-Yaakov 21 The effect of size
Slide 22: The effect of size and WDCV
Prof. Sam Ben-Yaakov 22 The effect of size and WDCV
Slide 23: ESR as a function of bias voltage
Prof. Sam Ben-Yaakov 23 ESR as a function of bias voltage
Slide 24: ESR ESL
Prof. Sam Ben-Yaakov 24 C ESR ESL C, ESR C1, ESR1 C2, ESR2 C1, C2 < C ESR1, ESR2 >ESR
Slide 25: Large capacitance: smaller ESR?
Prof. Sam Ben-Yaakov 25 ? Large capacitance Small capacitance Smaller ESR? Larger ESR?
Slide 26: Significant question because ceramic capacitors losses are:
Prof. Sam Ben-Yaakov 26 Significant question because ceramic capacitors losses are: 2 𝑃 = 𝐸𝑆 ∙ 𝑖𝑟𝑚𝑠 VC VAC S L VDC RL D CIN CO t IC t
Slide 27: With DC bias / Without DC bias
Prof. Sam Ben-Yaakov 27 With DC bias Without DC bias Z5U
Slide 28: Measurements by Omicron Lab
Prof. Sam Ben-Yaakov 28 Measurements by Mr. Hermann Haag of Omicron LAB, and Vorarlberg University of Applied Sciences, Austria using Omicron’s Bode 100 Network Analyzer
Slide 29: Prof. Sam Ben-Yaakov
Prof. Sam Ben-Yaakov 29 Bode 100 Source mode Receiver 1 Receiver bandwidth Receiver 2 Auto off v 10 Hz v l I Y__7_ Source level Attenuator 1 DUT settling time Attenuator 2 999 mVrms * 10dB ¥ Oms * 10dB ¥ Sweep time: - Internal External { Reference 9_| Reference i} CG _L AC _L AC & “T coupling “T cou
Slide 30: ESR C1812W334KCRACTU (same as K-SIM data)
Prof. Sam Ben-Yaakov 30 According to Bode 100 measurements ESR is increasing with bias (consistent with paper) ESR 0V bias 400V bias C1812W334KCRACTU (same as K-SIM data)
Slide 31: Specifics of the X7R Capacitors Application in High Frequency Inverters
Prof. Sam Ben-Yaakov Hk 2016 IEEE 36th International Conference on Electronics and Nanotechnology (ELNANO) Specifics of the X7R Capacitors Application in the High Frequency Inverters Alexey Tyshko Saulius Balevicius NATA Consulting LLC & PetroMar Technology Center of Physical Sciences and Technology
Slide 32: KG57NX7R2A106M data sheet
Prof. Sam Ben-Yaakov KG57NX7R2A106M Item DC Bias Characteristic {| Application & Main Feature i ° ‘Commercial Grade ( MEGACAP Type ) 24 ~ gs It Boo |) Series g= é (CKGS7N(S750) [EIA CC2220) a” N Re Ss oc Bios EL Dimensions L 6.00mm +/-0.5mm ch: ist hi risti WwW 5.00mm +/-0.5mm 12|, ESR vs. Freq. Cha
Slide 33: 80V bias increases ripple current loss by more than 10 fold
Prof. Sam Ben-Yaakov 33 80V bias increases ripple current loss by more then 10 fold! ???
Slide 34: X7R 0.33uF 500V
Prof. Sam Ben-Yaakov 34 X7R 0.33uF 500V 1812 Same as the one tested by Bode 100
Slide 35: K-SIM KEMET
Prof. Sam Ben-Yaakov 35 K-SIM KEMET Z ESR
Slide 36: According to K-SIM ESR is decreasing with bias
Prof. Sam Ben-Yaakov 36 According to K-SIM ESR is decreasing with bias (not consistent with papers and Bode100 results) 400V bias 0V bias 456mΩ & 10kHz 68mΩ & 10kHz
Slide 37: Prof. Sam Ben-Yaakov
Prof. Sam Ben-Yaakov 37 ?
Slide 38: Voltage bias effect on the ESR of ferroelectric ceramic capacitors
Prof. Sam Ben-Yaakov 38 Submitted to PCIM- 2020 Voltage bias effect on the ESR of ferroelectric ceramic capacitors Hermann Haag1, Florian Hämmerle1, and Shmuel (Sam) Ben-Yaakov2 1 Omicron Lab, Austria 2 Ben-Gurion University, Israel
Slide 39: X7R 15nF 1000V and 50V capacitors
Prof. Sam Ben-Yaakov 39 X7R, 15nF, 1000V capacitor X7R, 15nF, 50V capacitor (KEMET, C1206W153KDRACTU), (Wurth, 885012208082).
Slide 40: Summary of measured ESR and comparison to K-SIM simulation
Prof. Sam Ben-Yaakov 40 Table I. A summary of measured ESR and comparison to K-SIM simulation Material Capacitance Voltage ESR ESR change K-SIM X5R 3.3µF 25V +25.1% -68.0% X5R 10µF 25V +30.5% X5R 47µF 16V +1.2% X7R 330nF 50V +20.4% -20.0% X7R 2.2µF 50V +64.8% X7R 15nF 50V +13.7% X7R 15nF 1000V +76.3
Slide 41: Piezoelectricity
Prof. Sam Ben-Yaakov 41 Piezoelectricity 1. Ferroelectric dielectric is piezoelectric 2. Reciprocal relation between electrical field and mechanical stress 3. When electrically driven by AC ceramic capacitors emit acoustic waves 4. Multiple resonant frequencies 5. Can cinduce“ singing capacitors” ph
Slide 42: Capacitors for Reduced Microphonics and Sound Emission
Prof. Sam Ben-Yaakov 42 Capacitors for Reduced Microphonics and Sound Emission Mark Laps, Roy Grace, Bill Sloka, John Prymak, Xilin Xu, Pascal Pinceloup, Abhijit Guray, Michael Randall, Philip Lessner, Aziz Tajuddin KEMET Electronics Corporation, 201 Fairview Street Extension, Fountain Inn, SC 29644
Slide 43: Setup for measuring noise performance
Prof. Sam Ben-Yaakov 43 Function Generator Figure 10. Setup for measuring noise performance of test samples. Sound Pressure Meter
Slide 44: Overall Sound Pressure
Prof. Sam Ben-Yaakov 44 Overall Sound Pressure 100Hz Overall Sound Pressure 1kHz 60 X7R Control] -—* 55 X7R Control —* =a _ _ — ea ean Distortion X7R| = 45 es ower Distortion X7R s a a _—_—*® o* CoLF _— CoLF 46 7 — rr 4 30 Za x Noise Floor 25 ; : Noise Floor : ; 2 3 4 5 6 7 8 9 10 ) 1 2 3 4 5 6 Peak
Slide 45: ESR
Prof. Sam Ben-Yaakov 45 ESR ESR
Slide 46: ESR measurements
Prof. Sam Ben-Yaakov 46 Measurements by Mr. Hermann Haag of Omicron LAB, and Vorarlberg University of Applied Sciences, using Omicron’s Bode 100 Network Analyzer ESR
Slide 47: Experiment Setup for Film Capacitor
Prof. Sam Ben-Yaakov 47 Experiment Setup for Film Capacitor Measurements by Mr. Stanislav Tishechkin, Department of ECE, Ben-Gurion University, using Omicron’s Bode 100 Network Analyzer Film Film Film
Slide 48: Results for Film Capacitor
Prof. Sam Ben-Yaakov 48 Results for Film Capacitor ESR
Slide 49: Experiment Setup and results for X7R Capacitor
Prof. Sam Ben-Yaakov 49 Experiment Setup and results for X7R Capacitor ESR Film X7R Film 4.7uF 4.7uF
Slide 50: Submitted to PCIM - 2020
Prof. Sam Ben-Yaakov 50 Submitted to PCIM - 2020
Slide 51: DC biased ESR measurement schematic
Prof. Sam Ben-Yaakov 51 © Vac 10° _---YNA Output of] ' so | a DUT R ; rc | | | : co cH 10 ' Pas ' — ‘Ry oS | ae ' ' a boenoee een ee nee y hi 10" CHI Ry 10? 104 10° 10° 107 f/Hz Fig. 1: Schematic of the DC biased ESR measurement Fig. 2: ESR versus frequency of an X7R FDCC with different DC bias
Slide 52: Loss measurement schematic and calorimetric measurement
Prof. Sam Ben-Yaakov a | |—- VNA Output i Voltage Probe NA CH2 WYY\—_, + Y a isan uPaabe ; q Current Probe Seow Py = 200nF —— VNA CHI = pvt 1kO a rd Rioad 7 ! ‘ — puri Air i ! Scope GND i WY Transformer Oil f VNA GND ! f — Calorimetric Measurement = = = Polystyrene Fig. 3: Schematic of the loss meas
Slide 53: Losses in the capacitor at three frequencies
Prof. Sam Ben-Yaakov 53 0.45 0.35 455 46 465 47 475 48 485 49 4.95 5 f/ Hz x 105 Fig. 5: Losses in the capacitor at three different frequencies. Blue: Plossmeas. Red: Plosscale
Slide 54: ESR and piezoelectricity of ceramic capacitors: more research is required
Prof. Sam Ben-Yaakov 54 ESR and piezoelectricity of ceramic capacitors: more research is required
Slide 55: Nonlinear capacitors modeling
Prof. Sam Ben-Yaakov 55 Nonlinear capacitors modeling
Slide 56: Capacitance definition
Prof. Sam Ben-Yaakov 56 Capacitance definition 0.5Vrms Why the peak? 1VAC C VAC C VBIAS 1kHz Local, Small signal, Cd Large signal Cac
Slide 57: Which model is correct?
Prof. Sam Ben-Yaakov 57 Which model is correct? 𝑑𝑣 𝑖 = 𝐶(𝑣) 𝑑{𝐶 𝑣 ∙ 𝑣} 𝑑𝑡 𝑖= 𝑑𝑡 dv d (C (v) ) i = C (v ) +v dt dt
Slide 58: The fundamental property of a charge storing device - Q=f(V)
Prof. Sam Ben-Yaakov 58 The fundamental property of a charge storing device - Q=f(V) 𝑑{𝑄} 𝑖= 𝑑𝑡 Q Q 𝛼 V
Slide 59: Redefining 'capacitance'
Prof. Sam Ben-Yaakov 59 Redefining ‘capacitance’ Q (v ) Ct ( v ) = Total Capacitance v ∆Q Cac = dQ(v) Local Capacitance ∆V C d (v ) = dv Small signal ∆𝑄 𝐶𝑎𝑐 (𝑣, 𝐴) = Large signal Capacitance ∆𝑉
Slide 60: Redefining 'capacitance'
Prof. Sam Ben-Yaakov 60 Redefining ‘capacitance’ 0.5Vrms ∆Q Cac = ∆V
Slide 61: C t ( v ) = C d ( v ) = Q (
Prof. Sam Ben-Yaakov 61 Total Capacitance Local Capacitance Small signal Q (v ) ∆Q dQ(v) C t (v ) = Cac = ∆V C d (v ) = v dv 𝑄(𝑣) = 𝑣𝐶𝑡 (𝑣) Q(v) = Cd (v)dv 𝑑{𝑣𝐶𝑡 (𝑣)} 𝑖= dQ(v) dv 𝑑𝑡 = C d (v ) dt dt dv d (Ct (v) ) i = Ct ( v ) + v v 𝑑𝑣 dt dt C (v ) = 0 C (v)dv d 𝑖 = 𝐶𝑑 (𝑣)…
Slide 62: Conclusion: Both models are correct
Prof. Sam Ben-Yaakov 62 Conclusion: Both models are correct Provided that the ‘capacitances’ are defined properly dv d (Ct (v) ) 𝑑𝑣 i = Ct ( v ) + v 𝑖 = 𝐶𝑑 (𝑣) dt dt 𝑑𝑡 v C (v ) = C (v)dv 0 d t v
Slide 63: So why the peak?
Prof. Sam Ben-Yaakov 63 So why the peak? Cac
Slide 64: Thank you for your attention!
Prof. Sam Ben-Yaakov 64 Thank you for your attention!