Gan Systems GS-EVB-HB-0650603B-HD, Technical Manual

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GS-EVB-HB-0650603B-HD
Half Bridge Bipolar Drive Switch Board
Technical Manual
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GS-EVB-HB-0650603B-HD TM Rev. 210712 © 2021 GaN Systems Inc www.gansystems.com 6
Please refer to the Evaluation Board/Kit Important Notice on page # 16
2 Technical Description
2.1 Gate Pull Up and Pull Down Resistors
The HEY1011-L12C gate driver has independent output pins for the gate pull up and gate pull down
allowing control of the turn-on and turn-off rise and fall times.
The default values for these resistors are:
• OUTPU: R1 and R5 = 10 Ohms
• OUTPD: R3 and R7 = 1 Ohm
These values can be modified to suit your own application.
2.2 Enable and Start Sequence
The HEY1011-L12C has an open drain enable pin (EN) to facilitate a system level wired-AND start up.
When the enable pin is externally pulled low this forces the driver into a low power mode. The driver
output is pulled low in this mode. In the event of an internal fault condition, such as UVLO, this pin is
actively pulled low internally by the driver. During normal operation, the pin is released by the driver, and
must be pulled high with an external pull-high resistor. This functionality can be used by the PWM
controller as an indication that it can start sending IN pulses to the driver. It is typically wired AND with
the controller enable pin as shown in
Figure 2
below.
The GS-EVB-HB-0650603B-HD evaluation board provides direct access to the EN pin on connector
CONN1. Internally the board contains a 100k pull up resistor connected from VDRV to the EN_PU pin on
connector CONN1
– see schematic in
Figure 11
. If external control of the enable function is not required,
pins EN and EN_PU must be linked together on CONN1 to make use of the internal 100k pull up resistor
to enable the driver. If the EN pin is left floating, the drivers will not respond to INL or INH input signals.
Figure 2: HEY1011-L12C Wired-AND enable
The start up sequence of the HEY1011-L12C is shown in
Figure 3
below. Time T
START
is defined as the time
after which V
DRV
reaches the UVLO rising level to the HEY1011-L12C releasing the EN internal pull down.
IMPORTANT the IN signal must not be applied before the EN pin has been released.