GA50JT06-258 Datasheet, PDF (10/12 Pages) GeneSiC Semiconductor, Inc. – Normally – OFF Silicon Carbide Junction Transistor

GA50JT06-258
C: Proportional Gate Current Driving
A proportional gate drive topology may be beneficial for applications in which the GA50JT06-247 will operate over a wide range of drain
current conditions to lower the gate drive power consumption. A proportional gate driver relies on instantaneous drain current ID feedback to
vary the steady state gate current IG,steady supplied to the GA50JT06-247.
C:1: Voltage Controlled Proportional Driver
A voltage controlled proportional driver relies on a gate drive integrated circuit to detect the GA50JT06-247 drain-source voltage VDS during
on-state to sense ID. The integrated circuit will then increase or decrease IG in response to ID. This allows IG and gate drive power consumption
to reduce while ID is low or for IG to increase when ID increases. A high voltage diode connected between the drain and sense protects the
integrated circuit from high-voltage when blocking. A simplified version of this topology is shown in Figure 25. Additional information will be
available in the future at http://www.genesicsemi.com/references/product-notes/.
Gate Signal
Sense
Proportional
Gate Current
Driver
Signal
Output
HV Diode
D
G
IG,steady
S
SiC SJT
Figure 25: Simplified Voltage Controlled Proportional Driver
C:2: Current Controlled Proportional Driver
The current controlled proportional driver relies on a low-loss transformer in the drain or source path to provide feedback of the
GA50JT06-247 drain current during on-state to supply IG,steady into the gate. IG,steady will increase or decrease in response to ID at a fixed forced
current gain which is set be the turns ratio of the transformer, hforce = ID / IG = N2 / N1. GA50JT06-247 is initially tuned-on using a gate current
pulse supplied into an RC drive circuit to allow ID current to begin flowing. This topology allows IG,steady and the gate drive power consumption to
reduce while ID is relatively low or for IG,steady to increase when ID increases. A simplified version of this topology is shown in Figure 26.
Additional information will be available in the future at http://www.genesicsemi.com/references/product-notes/.
Dec 2014
Gate Signal
N2
SiC SJT D
G
S
N3
N1
N2
Figure 26: Simplified Current Controlled Proportional Driver
http://www.genesicsemi.com/high-temperature-sic/high-temperature-sic-junction-transistors/
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