EC9219 Datasheet, PDF (13/14 Pages) E-CMOS Corporation – TFT- LCD DC-DC Converters with Operational Amplifiers

TFT- LCD DC-DC Converters with Operational Amplifiers
EC9219
z Place all feedback voltage-divider resistors as close to their respective feedback pins as possible. The
divider’s center trace should be kept short. Placing the resistors far away causes their FB traces to
become antennas that can pick up switching noise. Take care to avoid running any feedback trace near
LX or the switching nodes in the charge pumps.
z Place the VIN pin bypass capacitors as close to the device as possible. The ground connection of the
VIN bypass capacitor should be connected directly to the SGND pin with a wide trace.
z Minimize the length and maximize the width of the traces between the output capacitors and the load
for best transient responses.
z Minimize the size of the LX node while keeping it wide and short. Keep the LX node away from
feedback nodes (FB) and analog ground. Use DC traces to shield if necessary.
Refer to the EC9219 DEMO BOARD for an example of proper PC board layout.
Package Dimension
TSSOP-14
P 13 / 14
Unit:mm
2009/09/29