GaN is Crushing Silicon EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 1
Agenda How egan FETs work Hard Switched DC-DC converters High Efficiency point-of-load converter Envelope Tracking buck converter Resonant DC-DC Converters Bus Converter ZVS Class D Wireless Power Transmission A Look into the Future Q & A egan is a registered trademark of Efficient Power Conversion Corporation EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 2
Power Switch Wish List Lower On Resistance Faster Less Capacitance Smaller Lower Cost EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 3
Material Comparison EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 4
State of the Art Theoretical on-resistance vs. blocking voltage capability for silicon, silicon carbide, and gallium nitride. EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 5
GaN Magic V S AlGaN GaN (Piezoelectric) D EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 6
Device Construction Concept Source Gate AlGaN Protection Dielectric Drain GaN Silicon Forms the foundation for a Depletion Mode device EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 7
Enhancement Mode egan FET S D A positive voltage from Gate-To-Source establishes an electron gas under the gate EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 8
Body Diode? No Minority Carriers = Zero Q rr S D A positive voltage from Gate-To-Drain also establishes an electron gas under the gate enabling reverse conduction EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 9
Cross Section of an egan FET EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 10
egan FET Low Voltage Product Family Solder side View Gate 2.1 x 1.6 mm Substrate (Connect to Source on PWB) Drain Source Part Number Package (mm) V DS (V) V GS (V) R DS(on) @5V (mω) Q G @5 V Typ. (nc) EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 11 Q GS Typ. (nc) Q GD Typ. (nc) R G Typ. (Ω) V th Typ. (V) EPC2015 LGA 4.1x1.6 40 6 4 10.5 3 2.2 0.6 1.4 0 33 150 EPC2014 LGA 1.7x1.1 40 6 16 2.5 0.67 0.48 0.6 1.4 0 10 150 EPC2001 LGA 4.1x1.6 100 6 7 8 2.3 2.2 0.6 1.4 0 25 125 EPC2016 LGA 2.1x1.6 100 6 16 4.1 0.93 0.75 0.6 1.4 0 11 125 EPC2007 LGA 1.7x1.1 100 6 30 2.1 0.5 0.6 0.6 1.4 0 6 125 EPC2010 LGA 3.6x1.6 200 6 25 5 1.3 1.7 0.6 1.4 0 12 125 EPC2012 LGA 1.7x0.9 200 6 100 1.5 0.33 0.57 0.6 1.4 0 3 125 Q RR (nc) I D (A) T J Max. ( C)
Ultra High Frequency egan FETs EPC Part No. BV (V) Max. R DS(ON) (mω) (V GS = 5V, Min. Peak Id (A) (Pulsed, 25 o C, I D = 0.5 A) T pulse = 300 µs) Typical Charge (pc) Q G Q GD Q GS Q OSS Q RR Typical Capacitance (pf) (V DS = 20 V; V GS = 0 V) C ISS C OSS C RSS EPC8004 40 125 7.5 358 31 110 493 0 45 17 0.4 EPC8007 40 160 6 302 25 97 406 0 39 14 0.3 EPC8008 40 325 2.9 177 12 67 211 0 25 8 0.2 EPC8009 65 138 7.5 380 36 116 769 0 47 17 0.4 EPC8005 65 275 3.8 218 18 77 414 0 29 9.7 0.2 EPC8002 65 530 2 141 9.4 59 244 0 21 5.9 0.1 EPC8003 100 300 5 315 34 110 1100 0 38 18 0.2 EPC8010 100 160 7.5 354 32 109 1509 0 47 18 0.2 * Preliminary Data Subject to Change without Notice EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 12
Threshold vs. Temperature 1.2 1.1 Normalized Thershold Voltage 1 0.9 0.8 0.7 egan FET MOSFET A 0.6-50 -25 0 25 50 75 100 125 150 Junction Temperature ( C) EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 13
Total Gate Charge EPC2001 = 100 V, 5.6 mω typ. BSC057N08 = 80 V, 4.7 mω typ. BSC057N08NS EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 14
egan FET Reverse Conduction MOSFET + Q RR egan FET + Zero Q RR EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 15
Conduction Figure of Merit Q G (nc) 100 10 Conduction Figure of Merit 200 V EPC 200 V Si 100 V EPC 100 V Si 40 V EPC 40 V Si 1 R DS(ON) (mω) 1 10 100 1000 EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 16
egan FET Loss Mechanisms Like A MOSFET I²R Conduction Loss Capacitive Switching Losses Gate Drive Losses V I Switching Loss Not Like A MOSFET High Reverse Conduction Loss No Body Diode Reverse Recovery Loss Can be much, much better than comparable silicon MOSFET EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 17
Design Examples EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 18
Design Example Hard-Switched DC-DC Conversion Buck Converter Envelope Tracking Resonant DC-DC Conversion Resonant Bus Converter Wireless Power EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 19
Ideal Hard Switching t VR t CF V IN V DS I OFF I DS V GS V PL V TH t EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 20
100 V Device Comparison 90 FOM = (Q GD +Q GS2 ) R DSON (pc Ω) 80 70 60 50 40 30 20 10 100 V egan FET Q GS2 Q GD Q GS2 Q GD 100 V MOSFETs Q GS2 Q GS2 Q GS2 Q GD Q GD Q GD 0 EPC 2001 FDMC86160 SiR870ADP BSZ150N10LS3 G AON7290 V DS =0.5*V DS, I DS = 10 A EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 21
egan FET vs MOSFET Efficiency (%) 100 95 90 85 80 75 70 65 60 40 V egan FET 40 V Si MOSFET Buck Converter 500 khz 1 MHz 55 80 V Si MOSFET 50 10 15 20 25 30 35 40 45 50 55 60 65 Input Voltage (V) 100 V egan FET 80 V Si MOSFET Measured Efficiency V OUT =1.2 V I OUT =10 A EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 22 22
Low Voltage Device Comparison FOM=(Q GD +Q GS2 )*R DSON (pc*ω) 35 30 25 20 15 10 5 40 V egan FET Q GS2 Q GD 40 V MOSFETs Q GS2 Q GS2 Q GD Q GD 25 V MOSFETs Q GS2 Q GS2 Q GD Q GD 0 EPC2015 BSZ097N04LSG BSZ040N04LSG BSZ060NE2LS BSZ036NE2LS V DS =12 V, I DS = 20 A EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 23
Optimal Layout Top View Side View Top View Inner Layer 1 Ref: D. Reusch, J. Strydom, Understanding the Effect of PCB Layout on Circuit Performance in a High Frequency Gallium Nitride Based Point of Load Converter, APEC 2013 EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 24
egan FET vs. MOSFET Efficiency Efficiency (%) 91 90 89 88 87 86 85 84 83 82 81 80 40 V Discrete egan FET 40 V Discrete MOSFET 25 V Discrete MOSFET 30 V Module MOSFET 2 4 6 8 10 12 14 16 18 20 22 Output Current (A) V IN =12 V V OUT =1.2 V f sw =1 MHz L=300 nh EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 25
Impact of Parasitics on Overshoot 40 V egan FET 30 V Si MOSFET Module 40 V Si MOSFET Switch Node Voltage 3 V/Div 20 ns/ div V IN =12 V V OUT =1.2 V I OUT =20 A f sw =1 MHz L=300 nh egan FET T/SR: EPC2015 MOSFET T:BSZ097N04 SR:BSZ040N04 MOSFET Module: CSD97370Q5M EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 26
EPC9107 Demonstration Board V IN =12-28 V V OUT =3.3 V I OUT =15 A f sw =1 MHz 2 x EPC2015 ~3V overshoot @ 15 A OUT V IN =28 V Switching Node Voltage V IN =28 V, I OUT =15 A ~1.1ns rise time @ 15 A 20ns 5 V/ div EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 27
Higher Current?...Parallel 97.5 97 1 x EPC2001 2 x EPC2001 4 x EPC2001 Efficiency (%) 96.5 96 95.5 95 T 1 T 4 SR 1 SR 4 SR 2 SR 3 T 2 T 3 94.5 2 6 10 14 18 22 26 30 34 38 42 Output Current (A) V IN =48 V, V OUT =12 V, f sw =300 khz EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 28
Envelope Tracking (ET) EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 29
Envelope Tracking W/O ET With ET Red represents wasted energy dissipated as heat Envelope Tracking can double base station efficiency. EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 30
Envelope Tracking Supply ET power supply topologies vary Hybrid / linear-assisted Buck* (one option) Buck ~10% Bandwidth ~ 90% Power Linear AMP ~ 10% Power Highest 90% of Bandwidth * V. Yousefzadeh, et. al, Efficiency optimization in linear-assisted switching power converters for envelope tracking in RF power amplifiers, ISCAS 2005 EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 31 31
Efficiency Efficiency 95% 90% 85% 80% 5 MHz V IN =42 V V OUT =20 V 10 MHz 75% 70% 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Output current (A) EPC8005 65 V 230 mω EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 32
Resonant Converters EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 33
Resonant Bus Converter High Frequency DC/DC Transformer L K1 S 1 V GS(Q2,Q4) V GS(S2) Q 1 Q 4 4:1 I LK1 V GS(Q1,Q3) V GS(S1) D V IN + - I PRIM C O I PRIM I LM 48V Q 2 Q 3 L M V DS(Q1) t ZVS V IN L K2 I Lk1 S 2 t 0 t 1 t 2 t 3 Ref: Y. Ren, M. Xu, J. Sun, and F. C. Lee, A family of high power density unregulated bus converters, IEEE Trans. Power Electron., vol. 20, no. 5, pp. 1045 1054, Sep. 2005. EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 34
P G = Q G V DR f s Gate Charge 600 500 egan FET MOSFET Q G *R DS(on) (nc*mω) 400 300 200 100 3x Q G *R DS(on) 4x 6x 0 20 40 60 80 100 120 140 160 180 200 220 Breakdown Voltage (V) EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 35
P G = Q G V DR f s Output Charge Q OSS *R DS(on) (nc*mω) 1600 1400 1200 1000 800 600 400 200 1.5x egan FET MOSFET 1.6x Q OSS *R DS(on) 2x 0 20 40 60 80 100 120 140 160 180 200 220 Breakdown Voltage (V) EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 36
egan FET vs. MOSFET Resonant Capacitors Secondary Devices Transformer Primary Devices Input Capacitors MOSFET vs. egan FET EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 37
ZVS Switching Comparison T ZVS = 42 ns egan FET V DS MOSFET V DS T ZVS = 87 ns MOSFET V GS egan FET V GS f sw = 1.2 MHz, V IN = 48 V, and V OUT 12 V EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 38
Duty Cycle Comparison D egan FET = 42% D MOSFET = 34% MOSFET V GS egan FET V DS egan FET V GS MOSFET V DS f sw = 1.2 MHz, V IN = 48 V, and V OUT = 12 V EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 39
Efficiency Comparison Efficiency (%) 98 97 96 95 94 93 92 91 1.2 MHz egan FET 1.2 MHz MOSFET 10 W 12 W 14 W Power Loss (W) 24 22 20 18 16 14 12 10 8 6 4 1.2 MHz MOSFET 5 A 1.2 MHz egan FET 90 0 5 10 15 20 25 30 35 40 Output Current (A) 2 0 5 10 15 20 25 30 35 40 Output Current (A) f sw = 1.2 MHz, V IN = 48 V, and V OUT 12 V EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 40
Resonant Converter Summary egan FETs improve high frequency resonant converter performance Lower output charge Lower gate charge More power delivery per cycle EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 41
Why Wireless Power? egan FETs enable higher efficiency and operation at safer frequencies The global wireless charging market is estimated to grow to $10B by 2018, a CAGR of 42.6% EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 42
Experimental System Setup Coil Feedback egan FETs RF connection Device Coil Device Board 25mm 50mm Source Board Source Coil RF connection EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 43
Wireless Coil-set Overview Simplified representation of coil-set for easy comparison between topologies C devs L devs L src L dev C devp C out R DCload Z load Coil Set EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 44
Class E Overview Switch voltage rating = > 3.56 Supply (V DD ). C OSS absorbed into matching network. V DD V / I + L RFck L e C s 3.56 x V DD V DS Q 1 C sh I D Z load 50% Ideal Waveforms time EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 45
ZVS Voltage Mode Class D C OSS Voltage is transitioned by the ZVS tank Lower egan FET C OSS leads to higher available duty cycle Highest system efficiency Q 1 C sp + V DD V / I V DD L m V DS I D Q 2 C m Z load ZVS tank 50% time Ideal Waveforms EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 46
Efficiency Efficiency [%] 84 82 80 78 76 74 72 70 68 66 6.78 MHz, 23.6 Ω Load, egan FET EPC 2012 EPC 2014 EPC 2012 0 6 12 18 24 30 36 Output Power [W] EPC 2007 ZVS-CD SE-CE CM-CD VM-CD egan FETs enable the highest efficiency in all topologies using 6.78 MHz and 13.56 MHz frequencies. EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 47
Impact of Load Per FET Power loss [mw] 800 600 400 200 ZVS-CD SE-CE CM-CD VM-CD 0 8 14 20 26 32 38 44 50 DC Load Resistance [Ω] ZVS class D has higher efficiency and a broader operating range than class E. EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 48
A Look into the Future EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 49
Silicon vs. egan Transistor Costs Starting Material Epi Growth Wafer Fab Test Assembly 2013 2016 lower lower higher lower same lower ~same? lower same lower OVERALL higher lower! EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 50
EPC Into the Future Mass Production 40 V - 200 V ~500 MHz Ultra High Frequency Family 1-3 GHz Launched Sept 2013 Higher Current 45 A Higher Voltage 600 V More functions on a chip Monolithic half bridge Driver on power chip Next Generation Devices 2 x FOM Improvement EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 51
Summary egan FETs enable exciting new applications have the potential to replace silicon power MOSFETs are straightforward to use, but they can t just drop them into a MOSFET socket. Some R&D is needed start today! EPC - The Leader in GaN Technology IEEE PELS 2014 www.epc-co.com 52