ADP3419 Analog Devices, ADP3419 Datasheet - Page 12

• Manufacturer Part Number: ADP3419
• Description: High Voltage MOSFET Driver
• Manufacturer: Analog Devices

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ADP3419
PC BOARD LAYOUT CONSIDERATIONS
Use the following general guidelines when designing printed
circuit boards. Figure 18 gives an example of the typical land
patterns based on the guidelines given here.
•
•
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The VCC bypass capacitor should be located as close as
possible to the VCC and GND pins. Place the ADP3419
and bypass capacitor on the same layer of the board, so
that the PCB trace between the ADP3419 VCC pin and
the MLC capacitor does not contain any via. An ideal
location for the bypass MLC capacitor is near Pin 5 and
Pin 6 of the ADP3419.
High frequency switching noise can be coupled into the
VCC pin of the ADP3419 via the BST diode. Therefore,
do not connect the anode of the BST diode to the VCC
pin with a short trace. Use a separate via or trace to
connect the anode of the BST diode directly to the VCC
5 V power rail.
It is best to have the low-side MOSFET gate close to the
DRVL pin; otherwise, use a short and very thick PCB
trace between the DRVL pin and the low-side MOSFET
gate.
Rev. A | Page 12 of 16
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Fast switching of the high-side MOSFET can reduce
switching loss. However, EMI problems can arise due to
the severe ringing of the switch node voltage. Depending
on the character of the low-side MOSFET, a very fast
turn-on of the high-side MOSFET may falsely turn on
the low-side MOSFET through the dv/dt coupling of its
Miller capacitance. Therefore, when fast turn-on of the
high-side MOSFET is not required by the application, a
resistor of about 1 Ω to 2 Ω can be placed between the
BST pin and the BST capacitor to limit the turn-on
speed of the high-side MOSFET.
Figure 18. External Component Placement Example
C
VCC
D1
R
BST
SHORT, THICK TRACE
TO THE GATES OF
LOW-SIDE MOSFETS
C
BST
TO SWITCH
NODE