is recommended for maintaining good common mode noise immunity. Open collector drive that allows IN1 and
IN2 to float will degrade common mode noise immunity and is therefore not recommended.
Printed Circuit Layout: Figure 5 shows the layout of the BG2C two channel gate driver board. The compact
2.7” x 2.4” circuit board with only 17 components clearly demonstrates the advantage of using hybrid gate
drivers and DC to DC converters. One important feature is the use of three ground plane islands for the regions
of the PCB having high voltage differences. Two of the islands are tied to the IGBT emitter/circuit common (Pin
2 of the DC to DC converters) of each output channel. The third island is connected to logic interface common
at pin 6 of CN1. This layout provides shielding to help prevent undesirable coupling of noise between the control
side and the gate drive channels.
Additional Information: Detailed information about the operation and electrical characteristics of the VLA507
and VLA513 hybrid gate drivers can be found on the individual device data sheets. Electrical characteristics
such as input voltage range, efficiency, and output voltage regulation of the VLA106-15242 and VLA106-24242
DC to DC converters can also be found on the individual device data sheets. Information about calculating gate
drive current and selection of series gate resistors (R
G
) can be found in the general IGBT module and gate drive
application notes. For applications using higher current IGBT modules refer to the application notes for the
VLA502-01 hybrid gate driver and BG2A reference design. All of these documents are available on the Powerex
website at www.pwrx.com. For design assistance with any of the products covered in this application note
contact Powerex at (724) 925-7272 and request application engineering. For product pricing and availability call
the Power Line: 1-800-451-1415.
Figure 5: BG2C Printed Circuit Board Layout
