TransphormHighest Performance, Highest Reliability GaN

GaN Technology

Why GaN-on-Si?

Silicon-based power transistors are reaching limits of operating frequency, breakdown voltage and power density in the power electronics industry and GaN’s performance is beginning to shine.  By no means is silicon going extinct, but energy requirements are continuing to increase, thereby requiring new methods and materials to be investigated/used to meet these demands.

Excellent characteristics for a power device

  • Superior breakdown capability compared to silicon
  • Increased bandgap giving higher blocking voltage with thinner material
  • Higher electron mobility than silicon and silicon carbide
  • Higher critical field results in a thinner more highly doped drift layer resulting in lower on-resistance (typically 10 times lower than Si)
Characteristic Unit GaN Si SiC
Bandgap eV 3.49 1.1 3.26
Electron mobility cm2/Vs 2000 1500 700
Peak electron velocity x107cm/s 2.1 1.0 2.0
Critical electric field MV/cm 3.0 0.3 3.0
Thermal conductivity W/cm * K >1.5 1.5 4.5
Relative dielectric constant er 9.0 11.8 10.0

Benefits of high voltage, low loss, high-speed GaN-on-Si switches

  • Reduced system size, weight and cost even against SiC
  • Increased efficiency
  • Smaller inductors/capacitors, heatsinks and PCB for overall system size reduction

Why Transphorm GaN?

Built on an industry-leading IP portfolio and over 300 years of combined GaN engineering expertise, Transphorm is delivering high performance with the highest quality and reliability GaN devices and best-in-class applications-driven design support to a growing customer base.

Quality/reliability
Transphorm has more experience than any other manufacturer qualifying GaN products, our supply chain is up to the task and our reliability data is always generated from randomly-sampled production material.

  • Transphorm qualified its first 600V GaN on Si HEMT in Jan of 2013 and has been in continuous production since
  • Second generation device qualified in Nov 2015 with improved performance
  • Supply chain is mature and able to manufacture at volume
  • Packaging technology follows standard industry form factors for ease of use and integration into existing product lines and proven reliability
  • More than ten GaN HEMT part numbers have been qualified to date

Read more about Transphorm quality and reliability.

Our technology:
Normally-off/Cascode – Normally-off devices are considered safer than normally-on and Transphorm pairs its normally-on, high-voltage GaN FET with a normally-off, low-voltage Si MOSFET. This creates a hybrid device that is normally-off and is compatible with Si drivers for added ease of use.  This results in an overall fast-switching device with a low conduction, switching and output losses. One important advantage of a Cascode switch is that no special driver is required.

Vgs for fully on (V) Max. Vgs rating (V) Safety Margin (V)
Transphorm Cascode 5 18 13
E-mode A 7 10 3
E-mode B 6 8 2
E-mode C 5 6 1

Transphorm 600V GaN Outperforms Si Superjunction
Superjunction MOSFET vs TPH3006PS: Reduced driving loss, switching loss and reverse recovery loss

Parameters Superjunction MOSFET TPH3006PS
Static Vds (25⁰C) 600V 600V
Rds (on) (25⁰C) 0.14/0.16Ω 0.15/0.18Ω
Qg 75nC 6.2nC
Qgd 38nC 2.2nC
Dynamic Co(er) 66pF [1] 56pF [1]
Co(tr) 314pF [1] 110pF [1]
Drain to Source Body Diode Characteristics Qrr 8200nC [2] 54nC [3]
trr 460ns [2] 30ns [3]

[1] Vgs = 0V, Vds = 0 – 480V
[2] Vds = 400V, Ids = 11.3A, di/dt = 100A/µs
[3] Vds = 480V, Ids = 9A, di/dt = 450A/µs

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