GaN Systems – Confidential – 1

Practical Solutions Design With GaN Power Transistors

December 5, 2017

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Topics

• GaN increases efficiency, reduces size, weight and system cost from 20 W to 20 kW• GaN E-HEMTs use similar design techniques to what designers do today• Ecosystem of support components• Creates new topologies, enhances existing topologies• GaN E-HEMTs lowest switching losses• GaNPX® packaging allows for cost effective superior thermal solutions

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GaNPX® vs TO-247

GaN Systems - Company Overview

• Market leader for gallium nitride (GaN) power transistors• Enhancement mode devices• 100V & 650V devices.• High current devices (100V to 90A, 650V to 60A)• Industry’s most robust gate drive with +10/-20V range

• Global company with decades of GaN experience • Overnight shipping through distribution since 2014• HQ and R&D in Ottawa, Canada• Global Sales & Applications support• World-class fabless manufacturing and advanced packaging

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650 V 100 VProducts

Eval kits, reference designs & power modules

Low Resistance. Low Gate Charge. High Voltage. Very High Currents. Simple Gate Drive

GaN product portfolio

FAQs, Datasheets, CAD symbols, STEP files, Thermal models, Pspice, LTspice models, Application Notes

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EV Battery Charger

Customers have proven the value proposition

>3X loss reduction

5X sizereduction

Solarin Silicon & 2X smaller in GaN

GaNSilicon

Inverter in Silicon & 5X smaller in GaN

GaN

Silicon

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Fundamentals of GaN Systems E-HEMT

GaN Enhancement mode High Electron Mobility Transistor (E-HEMT):• Lateral 2DEG (Two-dimensional electron gas) channel formed between AlGaN and GaN layers• Positive gate bias turns on 2DEG channel• 0V or negative gate voltage shuts off 2DEG and blocks forward conduction (allows reverse conduction)• Voltage driven: Gate driver charges/discharges (CGD + CGS)• No DC gate driving current needed: gate leakage current only (IGSS)

VGS

VDS

IGSS IDS2DEG

DRAIN

GATE

CGD

CGS

CDS

SOURCE

E-HEMT circuit modelGaN E-HEMT simplified structure

Simply put –A GaN E-HEMT is

just like a MOSFET but much much faster.

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Traditional PQFN + Wire Bond

Embedded GaNPX®

Proven embedded packaging for high speed GaN device: Extremely low inductance: high frequency switching Near Chip Scale embedded Packaging No wire bonding: high reliability Lower thermal resistance RθJC

Lsource~0.4nH

Time/uSecs 20nSecs/div

3.02 3.04 3.06 3.08 3.1 3.12 3.14 3.16 3.18 3.2

Vds

_Si /

V

-0

100

200

300

400

500

GD

S

Ls = ~10-15nH

TO-247

GaNPX®

High dv/dt Low VDS overshoot Better EMI

Package is important: GaN Systems GaNPX® embedded

Benefiting from the full capability GaN requires the right package

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Driving GaN is Straightforward

650V GaN Gate driver design• Voltage driven similar to Si MOSFETs：

• +5-6V for turn-on, 0V or negative for turn-off• Maximum +7/-10V，transient +10/-20V

• High side / half bridge gate drive:• Choose driver with high CMTI (>100V/ns)• Recommend isolated DC/DC, for Bootstrap:

• Bootstrap voltage stability: post-regulation• Watch for bootstrap diode loss at higher fsw

100V GaN gate driver design• RG(on) ~= 3-6.8 Ω, minimize gate and power loop inductance• Typically use half bridge driver IC with bootstrap, 0-5/6V

+9V

0V

DB1

+6V

C1

0VGDH

CB1

R1LP2985IM5-6.1

IN OUTGND

Bootstrap post-regulation

RG,extCGD

CGS

RG,int CDSGate

Drain

Source

Simpler to drive than SiC and IGBT. Lower voltage than MOSFET to fully enhance.

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Eco System of Partnerships with Industry Leaders

Gate Drivers Magnetics

Modules

Working with GaN is mainstream

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PFC – A comparison of topologiesBoost PFC• Fixed large diode bridge loss• Challenge to achieve higher than 98% efficiency

2-phase semi-bridgeless PFC• High component count and low component utilization• Additional return diodes D3/D4• D1/D2 needs to be fast-recovery diodes• No bidirectional capability

MOSFET-based bridgeless TP PFC • DCM mode High inductor current ripple• CrCM mode Complicated control• CCM mode Reverse-recovery loss due to Qrr

GaN enables most desired PFC topology … Bridgeless Totem Pole

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Totem Pole PFC: Enabled by GaN

VAC

L1

Q1

Q2

D1

D2

CB RL

Semi-bridgeless PFC – Si MOSFET Totem Pole PFC - GaN

Part count reduced by 33%

PFC Loss Breakdown → 15% lower

The Value of GaN

BOM Cost Improvement → 15% lower

Smaller Size • Higher frequency → Smaller filters• Better topology → Fewer parts• Lower loss → Smaller heatsink

Better Efficiency• Increases from 97.5% to 99%

Eff. 97.5%

Lower System Cost• Smaller EMI filter → less expensive • Smaller heatsink → less expensive

• No parasitic BJT and Body Diode• Zero Reverse Recovery• Reverse conduction, anti-Parallel

Diode not required

GaN makes smaller, more efficient, lower cost PFC solutions possible

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LLC DC/DC Converter – GaN Based DesignThe ZVS constraints of LLC converter

A smaller Coss leads to:

GaN-based half-bridge LLC converter

𝑇𝑇𝑑𝑑𝑒𝑒𝑒𝑒𝑑𝑑 ≥ 16 × 𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜(𝐸𝐸𝐸𝐸) × 𝐹𝐹𝑠𝑠 × 𝐿𝐿𝑚𝑚

Sufficient deadtime

Sufficient inductive energy from Lm

-

5

10

15

20

25

30

2010 2013 2016

Volu

me

(cm

3)

Magnetics volume

100 kHz

300 kHz

1 MHz

High efficiency

High power density

Resonant tank

Lm

Air gap Ptrans_loss

Irms Psw_cond

fs

Better switching characteristics of GaN improve LLC efficiency and size

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Application – Power Supply 200W AC/DC

Silicon92% efficient16.5 W losses12 W/in3

GaN96% efficient9 W losses30 W/in3

LLC

LLC

Diodebridge

Savings

PFC

PFC

System losses

4x Smaller

GaN lowers losses by > 45% and increases density by 2.5 times compared to silicon

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GaN E-HEMT Daughter Board

GaN E-HEMT X 2

Isolated Gate Driver

Same PCB layout for both boards• 2 oz. copper• 4 PCB layers• Homogeneous thermal vias

SiC MOSFET Daughter Board

Comparison GaN E-HEMT SiC MOSFETPackage GaNPX® D2PAKVDSmax 650 V 900 V

ID@25⁰C 30 A 35 ARDS(on)@25⁰C 50 mΩ 65 mΩ

VGS(op) -10/+7 V -4/+15 VCISS 260 pF 660 pFCOSS 65 pF 60 pFCRSS 2 pF 4 pFQG 5.8 nC 30.4 nCQGS 2.2 nC 7.5 nCQGD 1.8 nC 12 nCQRR 0 nC 245 nC

Let’s compare GaN to SiC

SiC MOSFET X 2

GaN and SiC boards created to exhibit same external parasitic effects

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• GaN E-HEMT (650V/50mΩ) vs SiC MOSFET (900V/65mΩ)• Switching test performed at 400V/15A half bridge hard switching double pulse test• Use same gate driver Silab Si8271 and RG(on)=10Ω, RG(OFF)=1Ω for both GaN and SiC

Switching Waveforms: GaN and SiC

GaN has 4x faster turn-on and 2x faster turn-off time than SiC MOSFET

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Eon=118.3uJ

SiC MOSFETGaN E-HEMT

400V/15A Eon measurement

Eon=41.15uJ

GaN E-HEMT

Eoff=11.02uJ

400V/15A Eoff measurement

SiC MOSFET

Eoff=33.8uJ400V/15A half bridge switching losses(Si8271GB-IS, RG(on)=10 Ω, RG(on) =2 Ω, TJ= 25°C)

Turn-on and Turn-off losses: GaN and SiC

GaN switching losses ~ 3x lower than SiC

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Lower losses benefits• Decrease heatsink size • Increase power density • Reduce operating cost• Increased lifetime

Temperature Effects: GaN and SiC

GaN has lower losses across full temperature range

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Synchronous Buck DC/DC System Efficiency and TJ400V-200V, 200kHz, Tamb = 25oC

Same layout, layers, vias, etc.

Power Loss and Junction Temperature Comparison at POUT = 900 W, fsw= 200 kHz

Efficiency and Temperature Rise: GaN and SiC

GaN increases efficiency up 1%

GaN is more than 60 °C cooler

GaN’s lower switching losses lower temp rise better, more reliable performance.

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Accelerating the Design Effort - IMS Evaluation Platform GSP65R25HB-EVB or GSP65R13HB-EVB

GaN High Power Half Bridge evaluation assembly(Gate Driver pcb + IMS HB)

IMS Half Bridge Boards(wo parallel and single transistor)

GSP65MB-EVB

High Power Full Bridge evaluation platform

mother board

Uses design concept of higher power GaN intelligent power modules (IPM).

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Thermal, Size and Layout Benefits of GaN

Optimized driver board minimizes both power and gate driver loops. Minimizes common source, power and gate driver loops

Vertical Mounting of HB IMS +Driver EVB makes good use of vertical height available in high power (> 5kW) designs.

IMS based evaluation platform augments the thermal and layout benefits of GaNPX

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GaN Systems today

Consumer

Datacenter

Industrial

Transportation

Shipping since 2014• Offices in 7 countries• Worldwide disti & direct sales

#1 in GaN• Highest current; broadest voltages• Best electrical performance• Best die & best package• Most widely used by customers

Customer successes• Solar Inverter and ESS• Motor Drives and Pumps• Wireless Power and Charging• AC Adapters• Datacenter Server and Rack Power• Automotive Onboard Charger

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GaN E-HEMTs in practical design solutions - Summary

• GaN-based power designs are more efficient, smaller, lighter • Higher efficiency (cuts losses 50-90%)• Smaller Size (reduces to 1/4 the size) – higher volumetric power densities (kW/l)• Lighter (typically 1/4 the weight) – higher gravimetric power density (kW/kg)

• Easy to use: similar drive to MOSFETs, low external parasitic effects• Enable BTP PFC topology

• No body diode Zero Reverse Recovery yet • Reverse conduction Capable anti-Parallel Diode not required

• Improve existing LLC topology • Low COSS, reduces Xformer losses, reduces rms current to reduce conduction losses

• Superior thermals: cost effective GaNPX® packaging• Lower costs: system, shipping, installation, maintenance and operating costs

PSU with Silicon

Same PSU with GaN

23www.gansystems.com • North America • Europe • Asia

Thank You for your time today …. Questions?