Ferrite and Metal Composite Inductors Design and Characteristics © 2019 KEMET Corporation What is an Inductor? Coil Magnetic Magnetic flux φ (Wire) Field dφ Core e = - dt Material i The coil converts electric energy into magnetic energy and stores it. e Core Material Current through the coil of wire creates a magnetic field Air Ferrite Metal and stores it. (None) (Iron) Composite Different core materials change magnetic field strength. © 2019 KEMET Corporation Ferrite Inductor or Metal Composite Inductor? Ferrite InductorFerrite Metal InductorMetal Composite MaterialMaterial Type type Ni-ZnNi-Zn Mn-Zn Mn-Zn Fe based Fe Based Very Good!! No Good.. InductanceInductace GoodGood! Very Good No Good Very Good!! Magnetic Saturation Good! No Good.. Good! No Good.. Very Good!! MagneticThermal Saturation Property Good No Good Very Good Good! Very Good!! Good! Efficiency Very Good!! No Good.. Good! ThermalResistance Property of core Good No Good Very Good Efficiency SBC/SBCPGood TPI Very GoodMPC, MPCV Good Products MPLC, MPLCV Resistance of Core Very Good No Good Good © 2019 KEMET Corporation Ferrite and Metal Composite Comparison Advantage of Ferrite 1. Higher inductance with high permeability 2. Stable inductance in the right range High L and Low DCR capability Advantage of Metal Composite 1. Very slow saturation 2. Very stable saturation for the thermal Core Loss Comparison Good for Auto app especially Advantage of Ferrite Very low core loss in dynamic frequency range Mn-Zn Ferrite Metal Core Low power consumption capability © 2019 KEMET Corporation SMD Power Inductor Lineup TPI MPC MPCV MPLC MPLCV SBC Under development Ferrite core Metal core Metal core Metal core Metal core Ferrite core (Mn-Zn) (Fe-Si-Cr or Amorphous) (Fe-Si-Cr) (Fe-Si-Cr or Amorphous) (Fe-Si-Cr) (Ni-Zn) Flat wire Flat wire Round wire Round wire Round wire Round wire (Direct terminal) (Direct terminal) (Direct terminal) (w/ lead-frame) (w/ lead-frame) (Discreate type) Assembled Molded Molded Molded Molded Assembled • Lowest DCR • Low DCR • Low DCR • Large Inductance • Large Inductance • Wide lineup • Lowest core loss • Soft saturation • Soft saturation • Soft saturation • Soft saturation • Good thermal • Low acoustic noise • Low acoustic noise • Low acoustic noise • Low acoustic noise property • Good thermal • Good thermal • Good thermal • Good thermal property property property property • AEC-Q200 • AEC-Q200 For For For For For For Large load converter Large load converter Automotive Light load converter Automotive Small load system (CPU, GPU, Mem) (CPU, GPU, Mem) (system side) (Smart meter, Audio) © 2019 KEMET Corporation Inductor Structure TPI Series Mn-Zn Core MPC/MPLC Series Molded Core Assembled Ferrite Molded Metal Molded Core Conductor & Terminals Wire Terminal The lower DCR Round Wire Wire Terminal Flat Wire (Large Inductance) GAP (Low DCR) GAP : Including the GAP into the core Mn-Zn Core Binder Advantage of molded metal Insulating coating Advantage of assembled ferrite • Smaller package Around the metal power • The lower DCR • Stable Inductance for thermal Metal Powder • The lower core loss • Low acoustic noise © 2019 KEMET Corporation When to Choose Ferrite or Metal Composite Interactive Architecture • TDP << Pmax(90A) • The lower core loss material • Fs : 1~3 MHz for low power consumption • Light load efficiency • Small footprint for low power loss on load Ferrite type • Shrinking : L x W Artificial Intelligence • TDP ≒ Pmax • Stable performance for • Fs : 1~3MHz high temp and peak power w/ Low loss metal material • In light of Pmax operation • Low height component Metal type to construct AI module • H: Low height restriction © 2019 KEMET Corporation Applications Automotive Notebook PC POL Servers Infotainment/LED lighting Desktop PC (DC-DC Converter) Application • Large current • High reliability • Low acoustic noise • Low consumption Requirement • Low consumption • Heat resistivity • Saturation in small package • Saturation in small package • TPI • MPCV • MPC • MPC Example • MPC • MPLCV • MPLC • MPLC MPN • MPLC • TPI TPI for CPU power MPLCV: AEC-Q200 TPI,MPC for CPU power MPC for large power sys MPC,MPLCG for system power Buck converter MPLCG for system power MPLCG for small power sys Note Buck converter Boost converter Buck converter Buck converter Boost converter © 2019 KEMET Corporation Competition Automotive Notebook PC POL Servers Infotainment/LED Lighting Desktop PC (DC-DC Converter) Application Competitors TPI series NA FP series PA series NA NA SRC series HCB series NA NA MPC/MPLC SPM series NA NA LHMI series IHLP series XAL series CMLB SRP series PCC series series series © 2019 KEMET Corporation Ferrite Inductor for Servers • AC Optimization • DC Optimization © 2019 KEMET Corporation Power Conversion for CPU Conventional Circuit 2nd stage Loss on the load line is a lot DC/DC Converter From the Wall 12V Power Distribution 1V CPU Improve power loss on the line Hard SW Topology to 1/16 by 48V power distribution With STC 1ST stage PSU (Switched tank converter) Efficient and scalable STC DC/DC Converter (Switched tank converter) 48V Power Distribution 12V 1V Soft SW topology Hard SW Topology AC Optimization Inductor DC Optimization Inductor © 2019 KEMET Corporation DC Optimization Inductor for the Hard SW Topology © 2019 KEMET Corporation DC Optimization Inductor For next GEN CPU The current for an inductor Need to reduce 456A(Imax) / 7p = 65A for Xμsec at 125C this distance between CPU and Peak power is going up and phases of DC/DC The space for Inductors Inductors converter is increased by GEN. It's necessary reducing product width and put inductors closer to CPU as possible to improve the loss on the road line. FET&IC P = I2 x R (≈ Distance) Size:11x8x8.2mm Size:10x6.5x9mm Size:11x6.0x10mm Vertical type Can be the option Current Shape for low height Saving Footprint Horizontal type Narrow width required © 2019 KEMET Corporation DC Optimization Inductor Generation 2018 2019 2020 Material GEN Current B45 NEW Suitable Freq. [kHz] 600~800 800~1500 1500~3000 Core Loss [mW/cc] 24 < 10 < 10 Permeability 2300 1000 ≈1000 Material : B45 Magnetic flux density 520 480 < 480 L : 10.0mm W : 6.5mm H : 9.0mm Current L [nH] DCR [mΩ] Isat [A] B45 Target 70 - >120 NEW Proposal 70 0.185 124 Engineering Sample： Available © 2019 KEMETf x B = 12500 Corporation TPI Series Line-up 1 DC optimization type Rated Current Typ. [A] (Reference) Package size L [nH] Temperature DCR [mΩ] Model L x W x H @100kHz, Rated Current at 25˚C Isat1 Isat2 Isat3 Max [mm] 0.1Vrms at 25˚C at 85˚C at 125˚C Typ. [A] TPI077050L070N 7.0 x 7.0 x 5.0 70 +/- 10% 0.28 Max 72 - - 40 TPI077050L105N 7.0 x 7.0 x 5.0 105 +/- 10% 0.35 Max 58 - - 31 TPI118082L150N 11.2 x 8.0 x 8.2 150 +/- 10% 0.29 +/-5% 93 79 67 50 TPI118082L180N 11.2 x 8.0 x 8.2 180 +/- 10% 0.29 +/-5% 79 67 57 50 Horizontal TPI128080L180N 12.0 x 8.0 x 8.0 180 +/- 10% 0.29 +/-5% 78 68 54 52 (Low Height) TPI128080L210N 12.0 x 8.0 x 8.0 210 +/- 10% 0.29 +/-5% 70 60 52 52 TPI128080L230N 12.0 x 8.0 x 8.0 230 +/- 10% 0.29 +/-5% 64 56 50 52 TPI706790L150N 6.7 x 7.0 x 9.0 150 +/- 10% 0.62 Typ. 60 51 44 29 TPI706790L180N 6.7 x 7.0 x 9.0 180 +/- 10% 0.62 Typ. 50 42 40 29 TPI106090L070N 10.0 x 6.0 x 9.0 70 +/- 10% 0.185 Typ. 162 134 114 56 Vertical TPI966410L120N 9.6 x 6.4 x 10.0 120 +/- 10% 0.145 Typ. 90 78 64 66 (Narrow width) TPI966410L150N 9.6 x 6.4 x 10.0 150 +/- 10% 0.145 Typ. 71 61 50 66 Under Development © 2019 KEMET Corporation AC Optimization Inductor for the Soft SW Topology © 2019 KEMET Corporation Development of Resonant Inductor Basic Structure of Resonant Inductor Basic structure Ferrite Core • The resonant inductor is comprised of upper and lower core using Mn-Zn ferrite, Conductor a center conductor and non-magnetic gap spacer. (Gap Spacer) • Enable the lowest resistance and the lowest core loss by simple structure for STC. Ferrite Core © 2019 KEMET Corporation Development of Resonant Inductor How to Modify Inductor for STC • Electrical current wave form in the STC utilizes the resonant is almost sine wave. • Reduction of AC loss component is very important. • The AC losses can be categorized into the ferrite iron loss, the copper conductor loss and fringing flux loss. • Need to focus on Core Loss and Eddy Current Loss to improve the total loss. * The skin effect can be led from frequency and so on. © 2019 KEMET Corporation Development of Resonant Inductor Material Selection for Core Loss Ferrite core for conventional hard switching Hard SW 35Ao-p, 300kHz STC utilizes series resonant with MLCC • Low core loss is required for wide range Magnetic Flux Density © 2019 KEMET Corporation Development of Resonant Inductor Inductor Design Modification for Fringing Flux Loss Ferrite Core Part A Air gap Part B Conductor Part A with visualized Air Gap Fringing Flux Part B with visualized Air Gap Fringing Flux 300mT in Ferrite Core 300mT in Ferrite Core 63.2mT at Conductor by fringing flux 37.9mT at Conductor by fringing flux Convectional magnetic structure Improved magnetic structure • Distance between the GAP and the conductor is necessary based on the amount of magnetic flux leakage © 2019 KEMET Corporation Development of Resonant Inductor Total Loss Comparison Loss Comparison 3 2.5W 2.5 -55% 2 1.1 1.5 0.3 1.1W 1 0.4 1.1 0.3 35Ao-p, 300kHz 0.5 0.4 0 STC utilizes series resonant with MLCC Conventional Magnetic Structure Improved Magnetic Structure Iron Loss Copper Loss Air Gap Fringing Flux Loss Material The Core Loss is improved with the suitable material for STC topology.