The egan FET Journey Continues egan FET Wireless Energy Transfer Solutions Efficient Power Conversion Corporation www.epc-co.com 1
Agenda Wireless Power Topologies Overview Wireless Power Results for each Topology Summary www.epc-co.com 2
Overview Output Power < 30 W Loosely coupled, 6.78 MHz (ISM band) based on A4WP standard Topologies Reviewed Class D (Current and Voltage Mode) Class E ZVS Voltage Mode Class D 3 www.epc-co.com 3
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 www.epc-co.com 4
Experimental Setup Coil Feedback egan FETs RF connection Device Coil Device Board 25mm 50mm Source Board Source Coil RF connection www.epc-co.com 5
Traditional Voltage Mode Class D Switch voltage rating = Supply (V DD ). Level shifting gate driver required. C OSS plays an important role in losses. + V DD Q 2 L mat C s V / I V DD V DS I D Q 1 C mat Z load 50% time Ideal Waveforms www.epc-co.com 6
Voltage Mode Class D Efficiency Efficiency [%] 72 6.639 MHz, 23.6 Ω load 68 64 60 56 52 48 EPC8004 EPC2014 MOSFET 2 4 6 8 10 12 14 16 18 Output Power [W] www.epc-co.com 7
Voltage Mode Class D Load Effect Efficiency [%] 63 62 61 60 59 58 57 56 55 54 53 52 6.699MHz, Fixed 14V supply EPC 2014 Efficiency Power 12 16 20 24 28 32 36 40 44 48 DC Load Resistance [Ω] 8.5 8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 Output Power [W] www.epc-co.com 8
Current Mode Class D EPC2012 has lower FoM than MOSFET C OSS is absorbed into matching network. V DD V / I L CK1 C pt L CK2 + π x V DD L pt V DS I D Q 1 Q 2 C sp Z load 50% time Ideal Waveforms 9 www.epc-co.com 9
Current Mode Class D Efficiency Efficiency [%] 85 80 6.78 MHz, 23.6 Ω Load EPC 2012 75 70 65 60 55 50 egan FET MOSFET 0 5 10 15 20 25 30 Output Power [W] www.epc-co.com 10
Current Mode Class D Load Effect 78.0 Fixed 5.5 V supply 14 77.5 13 Efficiency [%] 77.0 76.5 76.0 75.5 75.0 74.5 EPC 2012 Efficiency Power 12 11 10 9 8 7 Output Power [W] 74.0 14 18 22 26 30 34 38 6 DC Load Resistance [Ω] www.epc-co.com 11
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 www.epc-co.com 12
Class E Efficiency as Function of Load Efficiency [%] 6.78 MHz, 20.5 Ω Load 84 82 EPC 2012 80 78 76 74 72 70 0 5 10 15 20 25 30 Output Power [W] egan FET MOSFET www.epc-co.com 13
Class E Load Effect 6.78 MHz, Fixed 20 V supply 78 9.00 77 8.75 Efficiency [%] 76 75 74 73 72 71 70 Efficiency EPC 2012 Power 16 20 24 28 32 36 40 44 48 8.50 8.25 8.00 7.75 7.50 7.25 7.00 Output Power [W] DC Load Resistance [Ω] www.epc-co.com 14
Class E Thermal Performance NO HEAT-SINK 30 W, 20.2 Ω Load LM5113TM EPC2012 www.epc-co.com 15
Class E egan FET vs. MOSFET P FET [mw] 800 700 600 500 400 300 200 100 0 Total FET Power losses FDMC86248 EPC2012 0 5 10 15 20 25 30 35 Load Power [W] www.epc-co.com 16
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 www.epc-co.com 17
ZVS Voltage Mode Class D Efficiency Efficiency [%] 84 82 80 EPC 2007 78 76 74 72 70 68 35.4 Ω load 23.6 Ω load 0 5 10 15 20 25 30 35 40 Output Power [W] www.epc-co.com 18
ZVS Voltage Mode Class D Load Effect 81 Fixed 26 V supply 18 79 16 Efficiency [%] 77 75 73 71 EPC 2007 Efficiency Power 14 12 10 8 Output Power [W] 69 12 16 20 24 28 32 36 40 44 48 DC Load Resistance [Ω] 6 www.epc-co.com 19
ZVS Class D Thermal Performance NO HEAT-SINK R DCLoad = 35 Ω, V in = 42 V, P out = 35 W, f = 6.78 MHz LM5113TM EPC2007 www.epc-co.com 20
ZVS Class D FoM Comparison FOM [nc mω] 350 300 250 200 150 100 50 0 EPC2007 Q OSS R DS(on) Qoss RDS(on) QG RDS(on) Q G R DS(on) BV DSS = 100 V Q OSS = 8.9 nc at 40 V Q G = 2.1 nc at 5 V R DS(on) = 24 mω FDMC8622 BV DSS = 100 V Q OSS = 7.3 nc at 40 V Q G = 5.2 nc at 10 V R DS(on) = 43.7 mω www.epc-co.com 21
ZVS Class D egan FET vs. MOSFET P FET [mw] Total FET Power losses 1600 1400 1200 1000 FDMC8622 800 EPC2007 600 400 200 0 0 5 10 15 20 25 30 35 Load Power [W] www.epc-co.com 22
Summary of Efficiency Results Efficiency [%] 84 82 80 78 76 74 72 70 68 66 6.78 MHz, 23.6 Ω Load, egan FET EPC 2014 EPC 2012 0 6 12 18 24 30 36 Output Power [W] EPC 2012 EPC 2007 ZVS-CD SE-CE CM-CD VM-CD www.epc-co.com 23
Simulated FET Losses All Topologies Per FET Power loss [mw] 800 Exceeds thermal capability of FET Fixed Supply Voltage 600 400 200 15 W ZVS-CD SE-CE CM-CD VM-CD 0 8 14 20 26 32 38 44 50 DC Load Resistance [Ω] www.epc-co.com 24
Summary Wireless Power Transmission is one of the largest potential markets for power transistors. ZVS Class D shows great promise for a simple, low cost, and high efficiency topology for wireless power. egan FETs enable greater duty cycle and higher efficiency. egan FETs enable the highest efficiency in all topologies using 6.78 MHz and 13.56 MHz frequencies. egan technology is disruptive. www.epc-co.com 25
The end of the road for silicon.. is the beginning of the egan FET journey! www.epc-co.com 26