The Future of Power: High-Frequency Systems Enabled by GaN
The Future of Power: High-Frequency Systems Enabled by GaN
April 2021
Dong Lin, Sr. Director, Applications, [email protected]
Stephen Oliver, VP Corp. Mktg. & IR, [email protected]
World’s first and only GaN power IC company Over 18Mu shipped and zero failures
Energy to revolutionize power electronics
Energy to accelerate change
Energy to make a sustainable difference for our world
GaN is a high-speed semiconductor that switches up to 100x faster than Si and enables more efficient, smaller, lighter, cooler and lower cost systems; delivering 30-40% in energy savings.
Leonardo da Vinci
1452-1519
Frustrated Genius:
Strong ideas…
…Weak tools
The Enabling Force
Power GaN Technologies
Power ICs: Single, Half-Bridge
• Monolithic integration, 650V/800V, 2MHz
• GaN Power FET(s) + Driver + Control + Protection
• Features: on-board regulators, hysteretic input, level-shift, bootstrap, dV/dt control, UVLO, shoot-through & ESD protection
• “Digital In, Power Out”
2x Energy Savings at 27-40 MHz
The evolution of Flyback Frequency
QR Flyback Losses
• Quasi-Resonant (QR) Flyback
• Frequency-dependent losses
• Frequency-dependent losses
• Leakage inductance
• Snubber/clamp
• Partial hard-switching at high line
• Slow turn-on to minimize EMI
• Difficult to improve efficiency at high frequency
Mass Production: ACF
No Cap, Thin Transformer
• 60% thinner/smaller transformer
• 80% smaller output caps
• No electrolytic bulk cap
• Easier EMI
• 10x increased frequency
• Planar shield layer
• More consistent parameters
Pulsed-ACF
• Topology:
• Rectified AC 100Hz feeds directly into high-frequency ACF
• ACF maintains 100 Hz smooth pulse output to charge the phone’s battery, even if input voltage range is wide
• Stability, and accurate current and voltage monitor critical
• Eliminates electrolytic bulk capacitor
• OPPO-proprietary ‘direct-charge’ means during each pulse gap, polarization effect in the phone battery is eliminated, reducing wear-out mechanisms and extending battery life
• Powertrain:
• 2x Navitas NV6115 (170mOhm GaNFast power ICs)
• Low RDS(ON to minimize ‘on-state’ losses
• Minimal COSS for best ‘switching’ performance
• Control:
• TI UCC28782 ACF + On Semi NCP51530
• High-speed, soft-switching (~500 kHz)
The evolution of Front-End Frequency
Rectifier on Fire!
Rectifier on Fire!
2016: 1MHz CrCM Totem-Pole
300W Totem-Pole PFC
• Output : 400V (300W)utput : 400V (300W)
• Fast FETs : NV6117 (110mΩ) GaN Power ICs
• Slow FETs : Si Superjunction (62mΩ)
• Frequency : 300-1,200 kHz
• Size : 53.3 x 57.5 x 20 mm = 62 cc uncased (DSP controller board not included)
• Power Density: 4.9 W/cc (80 W/in3) uncased
• Target Efficiency : 98.5% @ 220VAC, 98% @ 110VAC, 97.5% at 90VAC, full load
Dr. Weijing Du, Navitas, 2018
NV6128: 70mΩ GaNFast Power IC
Integration Drives Performance
Only GaNFast is Fast… and Safe
Double-Pulsed Test (Sync Boost Circuit)
“Best GaN We Tested!”
Partner Feedback:
“Protected gate removes external parts without restricting switching speeds”
“Minimal ringing optimizes EMI”
“No gate-loop risks”
“Fast and very clean switching”
“Easy to control slew rates”
“Integrated gate allows fast switching”
(dV/dt > 200 V/ns, di/dt >10 A/ns)
High-Frequency HVDC
Quarter (¼) Brick, 400 VIN
