Application Note
3 of 23
V 1.1
2020-11-09
CoolGaN™ 600 V half-bridge evaluation platform featuring GaN
EiceDRIVER™
Introduction
1
Introduction
This 600 V gallium nitride (GaN) half-bridge evaluation board enables easy, rapid setup and test of CoolGaN™
transistors along with the dedicated GaN EiceDRIVER™ isolated gate driver IC. The generic topology is
configurable for boost or buck operation, pulse testing or continuous full-power operation. Test points provide
easy access to connect signals to an oscilloscope for measuring the switching performance of CoolGaN™
transistors and gate driver. This board saves the user the time to design their own gate driver and power circuit
to evaluate GaN power transistors.
The half-bridge circuit board has a single PWM input intended for connection to a 50 Ω pulse or signal
generator. Board power comes from a single 5 V supply input, which powers everything including the isolated
gate driver power supplies. Deadtime between the high and low-side is pre-set to 100 ns, but is adjustable via
trimpots. An external (user-supplied) inductor connects to the supplied pluggable terminal-block connector.
The output and bus voltage can range up to 450 V, limited by the capacitor rating. This half-bridge can switch
continuous currents of 12 A, and peak currents of 35 A, hard or soft-switching. Operating frequency can be up to
several MHz, depending on transistor dissipation (limited to about 15W per device with appropriate heatsink
and airflow).
1.1
Evaluation board specifications
Table 1
Evaluation board specifications and limits
Parameter
Values
Unit Note
Min. Typ. Max.
V
cc
input voltage
4.8
5.0
5.2
V
V
cc
input current
50
100
250
mA
Highest current at maximum frequency
PWM logic input levels
0
5
V
Standard 5 V TTL levels, 50 Ω terminated
V
in+
to V
in-
0
390
450
V
Limited by capacitor voltage ratings
V
O
to V
in-
0
450
V
(There may be ±30 V spikes appearing on Vo)
Transistor current, DC
12
A
Keep case temp below 125 °C
Transistor current, pulse
35
A
Keep case temp below 125 °C
Transistor power dissipation
15
W
With heatsink, airflow to keep T
case
<125 °C
Operating frequency
(DC)
3
MHz
Within dissipation, temperature limits
PWM pulse width
130
∞
ns
With 100 ns deadtime setting
V
SW
transition time
5
ns
8 A load, 10-90 percent rise, fall times
Gate drive voltage levels
-8
4
V
These are not limits, typical – and + values
Deadtime adjustment range
0
180
ns
Default setting is 100 ns. If longer deadtime
is necessary, C11, 21 can be increased,
thereby extending the adjustment range.
Note:
The PCB dimensions are 76x76 mm.