650v allgan™ power ic for power supply applications
TRANSCRIPT
650V AllGaN™ Power IC for Power Supply Applications
4th IEEE Workshop on Wide Bandgap Power Devices and Applications (WiPDA)Fayetteville, NC, USA. November 9th 2016.
Marco Giandalia, VP IC [email protected]
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AllGaN™ applications
Device Voltage (V)
GaN(Lateral)
SiC(Vertical)
1kW
10kW
Ap
plic
ati
on
Po
wer
600V 1,200V30V 100V
Micro-inverters
Commercial Solar String
Inverters
100W
LaptopAdapters
Smartphone,Tablet Chargers
TV, Game Players
Mobile Wireless Power
ServerPower
Class DAudio
EV Inverters
Industrial Drives, Welders, UPS,
Inverters
3,300V
10W
100kW
300V
On-board Battery Chargers & DC/DC
Converters
1MW+
LED Lighting
From GaN FET to GaN Power IC
• Efficient and safe gate driving
• Integration• eMode power FET
• Optimized gate driver
• Logic and protection
• Benefits• Reduced propagation delay
• Reduced turn-off falling time
• Reduced switching loss
• Smaller magnetics and capacitors
• Layout flexibility
4
HV Monolithic GaN Power IC
Gate Driver Basic Requirements
• Drive the gate with appropriate Turn-On and Turn-Off levels
• Avoid any voltage spikes or ringing that degrade the switching transition and affect device reliability
What is the Desired Voltage Range ?
0
1
2
3
4
5
6
7
8
9
10
0 1 2 3 4 5 6 7 8
Normalized RDS(ON)
5 ≤ 𝑉𝑔𝑠 ≤ 7𝑉
Turn-OnTurn-Off
Gate Loop Equivalent Circuit:GaN FET + External Driver
VDD
Gate driver loop
VIN VOUT
Discrete Approach Requires Rdamp
𝑅𝑑𝑎𝑚𝑝 ≥4(𝐿𝑔 + 𝐿𝑠)
𝐶𝑔𝑠
Lg+Ls [nH] Rdamp [Ω]
0 0
1 2.83
2 4
3 4.9
4 5.66
VDD
Gate driver loop
VIN
𝑹𝒅𝒂𝒎𝒑𝑳𝒈
𝑳𝒔𝑳′𝒔
𝑳𝒅
𝑳𝒍𝒐𝒂𝒅
Driver HV power FET
VOUT
• Damping resistor is needed to reduce oscillation and voltage spike at the power FET gate
Cgs = 500pF
Rdamp …does?
Rdamp = 0 Ω
Rdamp = 1 Ω
Rdamp = 2 Ω
Vgs I load
Rdamp = 4 Ω
Vgs I load V ds
Gate Loop Equivalent Circuit:AllGaN™ Power IC
10..30V
10..30V
VDD
Gate driver loop
VIN
𝑳′𝒔
𝑳𝒅
𝑳𝒍𝒐𝒂𝒅
Driver HV power FET
VOUT
Integrated Driver: 10x faster Turn-off
External driver + 4 Ω
Integrated driver
VGS I LOADVDS
External driver + 4Ω
Integrated driver
Tf = 5 ns
Tf = 0.6 ns
Vgs I load V ds
Integrated Driver in ZVS
High Side Sync Rect
ZVS soft switching Zero Loss Turn-off Low Side Sync Rect
Vgs of Low Side FET
1MHz ZVS
Vds of Low Side FET
200 ns/div
Speed & Integration Zero Turn-off Losses
13Load Current (A)
External drivers• Significant turn-off losses
• Only few nH of gate loop inductance causes voltage spikes that create unintended turn-on of the GaN FET
• Adding a gate resistor reduces spikes but slows down the circuit creating additional losses
Integrated GaN drivers (iDrive™)• Eliminate the problem
• Negligible turn-off losses0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 1 2 3 4 5 6 7 8 9 10
Externaldriver,noRg
Externaldriver+1Ω
Externaldriver+2Ω
Externaldriver+4Ω
Integrateddriver,noRg
Turn
-off
Lo
ss (
μJ)
Device Package
• Leadframe-based 5X6mm power package outline
• Low profile, small footprint with HV clearance
• Low inductance power connections (~0.2nH)
• Low thermal resistance (<2oC/W)
• I/O pins enough for drive functions
• Reliable
• Low cost0.85mm
Typical Connection Diagram
10..30V
• External components:o VCC decoupling capacitor (absolute
maximum rating 30 V) o Zener diode as voltage reference o RC network to set the desired turn-on
dV/dt rating (150 V/ns to 15 V/ns)
• Static Pdrv= 9 mW (only 35 mW at 1 MHz)• Propagation delay = 10-20 ns
Half-Bridge Configuration
dV/dt sel
dV/dt sel
• Bootstrap circuit is the most practical and effective way to derive power supply for the high-side power FET
• When the body diode of the low side is active, the switch node goes negative by 2~4V depending on the load current amplitude
• On-chip voltage regulator ensures a stable FET gate voltage
Benchmark Power Density Today
4.57 in (116 mm)
2.1
7 in
(55
mm
)
0.7
1 in
(18
mm
)
EMI Filter
SR Daughtercard:2x NCP43052x NVMFS5C628NL
Bu
lk C
ap
AC Rectifier
Ou
tpu
t C
aps
PFC + LLC Control DaughtercardNCP1516 (PFC), NCP1399 (LLC)
PFC + LLC Powertrain DaughtercardGaN Power ICs
LLCTransformer
• AC-19VDC 150W (Navitas and ON Semiconductor collaboration)
• 300kHz – limited by available control ICs
• Power Density : 1.31 W/cc (21.4W/in3)1.03 W/cc (17 W/in3) with 1.5mm case = 40% increase on best-in-class
Benchmark Power Density Tomorrow
• AC-19VDC 150W
• GaN Power ICs
• 1 MHz – DSP-controlled• Not optimized for light-load operation
• Power Density : 26.4 W/in3 = > 2x increase vs. best-in-class
Xiucheng Huang, "High Frequency GaN Characterization and Design Considerations," Ph.D Dissertation, Dept. Electr. Eng., Virginia Tech., Blacksburg, VA, USA, 2016.
650V AllGaN™ Power IC for Power Supply Applications
4th IEEE Workshop on Wide Bandgap Power Devices and Applications (WiPDA)Fayetteville, NC, USA. November 9th 2016.
Marco Giandalia, VP IC [email protected]
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