Power Devices Prof. Dr. Ing. Hans Georg Herzog (hg.herzog@tum.de) Prof. Dr. Ing. Ralph Kennel (ralph.kennel@tum.de) Technische Universität München Arcisstraße 21 80333 München Germany 1
Power Devices in power electronics active operation of power semiconductor devices is avoided either the voltage at the device is 0 or the current in the device is 0 unfortunately power semiconductor devices are no ideal switches! what requirements have to be postulated? switch off switching event switch on low blocking current low switching losses low voltage drop bidirectional blocking short switching time bidirectional conduction high blocking voltage free control of time of switching high current capability high du/dt no snubber circuits high di/dt 2
Losses in Real Power Semiconductor Devices switch-on losses conduction losses switch-off losses 3
Hard Switching Devices high stress on semiconductor wide SOA (safe operation area) necessary low switching frequency problematic with respect to high power 4
Soft Switching Devices low stress on semiconductor high switch-off current possible high switching frequency simple gate driving circuits additional power components necessary 5
IGBT Turn-Off with Snubber hard switching with snubber Gate voltage Gate voltage Collector voltage Collector current Collector voltage E off = 226µJ E off = 98µJ Collector current 400V, 20A, 125 C, R G = 9.1Ω current pops up but losses are still greatly reduced in the semiconductor the overall losses, however, increase 6
Power Devices Diode (Thyristor, GTO, IGCT) Referents: Prof. Dr. Ing. Hans Georg Herzog (hg.herzog@tum.de) Prof. Dr. Ing. Ralph Kennel (ralph.kennel@tum.de) Technische Universität München Arcisstraße 21 80333 München Germany 7
Power Diode Characteristic 8
Power Diode Switching-Off Behaviour 9
PIN - Diode to ensure a sufficient voltage capability the junction area is increased in distance p i n by introducing a so-called intrinsisc layer (= semiconductor material without any doping) between the p-doped and the n-doped layer PIN - Diode 10
Thyristor Structure A C A A 11
Thyristor Characteristic 12
Triac 13
/ GTO standard thyristor technology single wafer until 150 mm low conduction losses high current capability high switching losses high power for driver circuit 14
GTO IGCT both are controllable thyristors however, according to different philosophies GTO earlier in the market switch-off concept : by deviating a part of the load current (ca. 30 %) via the gate filigrane structure on the chip IGCT (too) late in the market switch-off concept : by deviating the full load current via the gate very complex driver circuits 15
Power Devices (bipolar) Transistor Referents: Prof. Dr. Ing. Hans Georg Herzog (hg.herzog@tum.de) Prof. Dr. Ing. Ralph Kennel (ralph.kennel@tum.de) Technische Universität München Arcisstraße 21 80333 München Germany 16
Bipolar Power Transistor 17
Switch-On Behaviour of a Bipolar Power Transistors 18
Switch-Off Behaviour of a Bipolar Power Transistors 19
Darlington Structure transistor in saturation U CE1 < U BE1 U BE1 = 0,7 V U BE2 = 0,7 V U CE1 = 0,3 V U CE2 = 0,7 V + 0,3 V = 1,0 V transistor achieve saturation U CE2 >> U BE2 very high conduction losses 20
Power Devices Field Effect Transistor (FET) Referents: Prof. Dr. Ing. Hans Georg Herzog (hg.herzog@tum.de) Prof. Dr. Ing. Ralph Kennel (ralph.kennel@tum.de) Technische Universität München Arcisstraße 21 80333 München Germany 21
Field Effect Transistor (MOSFET) Structure channel : long and thin high internal resistance 22
Field Effect Transistor (MOSFET) Structure channel : still thin - but not as long any more low internal resístance 23
Field Effect Transistor (MOSFET) parasitic npn-transistor 24
Field Effect Transistor (MOSFET) parasitic capacitances 25
Power Devices Insulated Gate Bipolar Transistor (IGBT) Referents: Prof. Dr. Ing. Hans Georg Herzog (hg.herzog@tum.de) Prof. Dr. Ing. Ralph Kennel (ralph.kennel@tum.de) Technische Universität München Arcisstraße 21 80333 München Germany 26
Insulated Gate Bipolar Transistor (IGBT) Structure 27
Insulated Gate Bipolar Transistor (IGBT) Structure and Equivalent Circuit bipolar pnp-transistor Think of it as a MOSFET with low conduction loss. 28
Insulated Gate Bipolar Transistor (IGBT) parasitic capacitances 29
Insulated Gate Bipolar Transistor (IGBT) parasitic (latch-up) transistor this is a parasitic thyristor!! 30
MOSFET technology chip size until 20 x 20 mm² low power for driver circuit low switching losses high voltage drop contacting problems 31
On-State Voltage Comparison Same Die Size On-State Voltage vs. Current APT6038BLL: I D = 17A APT30GP60B: I C2 = 49A APT6038BLL (25 C) APT6038BLL (125 C) APT30GP60B (25 or 125 C) Voltage (V) 60 50 40 30 20 10 0 0 10 20 30 40 Current (A) MOSFET 125 C MOSFET 25 C IGBT IGBT has lower on-voltage above about 4 Amps. MOSFET conduction loss is sensitive to temperature, the IGBT is not. TECHNOLOGY TO THE NEXT POWER 32
Conduction Loss Comparison Same Die Size Conduction Loss vs. Current (125 C) APT6038BLL APT30GP60B Power (W) 1400 1200 1000 800 600 400 200 0 MOSFET IGBT 0 5 10 15 20 25 30 35 40 Current (A) IGBT has much lower conduction loss above about 4 Amps. IGBT has much better overload capability. TECHNOLOGY TO THE NEXT POWER 33
Switching Loss: 54A MOSFET vs. 72A IGBT Power MOS 7 MOSFET Power MOS 7 IGBT V GS V GS E off = 1062 µj E off = 1058 µj Current Voltage Current Voltage Tail current APT6010B2LL, 400V, 50A, 125 ºC, 5 Ohms APT50GP60B, 400V, 50A, 125 ºC, 5 Ohms At 50A, the IGBT has lower conduction loss and lower switching loss. At less current, the MOSFET would have lower E off (no tail current). The IGBT is about half the size of the MOSFET lower cost. 34 TECHNOLOGY TO THE NEXT POWER 34
Application Comparison Hard Switched Boost Frequency (khz) 500 400 300 200 100 Frequency vs. Current APT15GP60B APT6029BLL MOSFET IGBT Boost: Hard switched 400V, T J = 125 C, T C = 75 C, 5 APT15GP60: I C2 = 30A APT6029: I D = 21A MOSFET is 2.5 times larger than IGBT. IGBT has good overload capability. 0 5 10 15 20 25 30 Current (Amps) MOSFET is best at low current, very high frequency. IGBT is best at high current. IGBT is lower cost. TECHNOLOGY TO THE NEXT POWER 35
Advantage of IGBTs Lower cost much smaller die size for same power. Excellent overload capability linear conduction loss versus current, very insensitive to temperature. Simple gate drive can replace MOSFETs positive only gate drive Highest speed IGBTs turn-on is the same as a MOSFET, turn-off is only slightly longer. Suitable for soft and hard switching zero voltage or reduced voltage turn-off not as good as MOSFETs. TECHNOLOGY TO THE NEXT POWER 36
Parallel Connection of IGBTs additional resistors in series semiconductor design with integrated path with a positive temperature coefficient 37
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Siliziumkarbid (SiC) 39
Reasons for Wide Band Gap Devices Added Value and Related Impact source : Pierric Gueguen, Market & Technology Overview of Power Electronics Industry and Impact of WBG Devices, Yole Développement, SEMICON Europa 2014, Grenoble, 09.10.2014 40
Quelle : Teresa Bertelshofer; Universität Erlangen 41
Quelle : Teresa Bertelshofer; Universität Erlangen 42
Quelle : Teresa Bertelshofer; Universität Erlangen 43
Quelle : Teresa Bertelshofer; Universität Erlangen 44
Quelle : Teresa Bertelshofer; Universität Erlangen 45
Quelle : Teresa Bertelshofer; Universität Erlangen 46
Quelle : Teresa Bertelshofer; Universität Erlangen 47
Comparison Si SiC (switching) losses source : www.infineon.com/sic; Power Electronics Europe ; Issue 6 2009 Efficiency Improvement with Silicon Carbide Based 48Power Modules
Quelle : Teresa Bertelshofer; Universität Erlangen 49
Quelle : Teresa Bertelshofer; Universität Erlangen 50
SiC Device Application Roadmap source : Pierric Gueguen, Market & Technology Overview of Power Electronics Industry and Impact of WBG Devices, Yole Développement, SEMICON Europa 2014, Grenoble, 09.10.2014 51
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Silicon Carbide (SiC) better (faster?) switching higher temperature robustness voltage drops? cannot be produced on outsourced production lines for memory chips investment cost not negligible 53
Key Characteristics of GaN vs. SiC vs. Si source : ECPE 54
Thank You!!! Any Questions? Prof. Dr.-Ing. Ralph Kennel Technische Universität München Electrical Drive Systems and Power Electronics 55