RT5779A/B
Functional Pin Description
Pin No.
Pin Name
Pin Function
Open-drain power-good indication output. The power-good function is activated
after soft-start is finished.
1
PGOOD
Power input. The input voltage range is from 2.5V to 6V. Connect a suitable input
bypass capacitor (typically of greater than 10F) between this pin and PGND. The
bypass capacitor should be placed as close to the IC as possible.
2
VIN
Switch node between the internal switch and the synchronous rectifier. Connect
the output LC filter from this pin to the output load.
3
4
5
6
LX
Power ground. This pin, connected to analog ground, must be soldered to a large
PCB copper area for maximum power dissipation.
PGND
VOUT
AGND
Output voltage sense input. This pin is used to monitor and adjust output voltage
to enhance load transient regulation.
Analog ground. It provides a ground return path for the control circuitry and
internal reference.
Feedback voltage input. Connect this pin to the midpoint of the external feedback
resistive divider to set the output voltage of the converter to the desired regulation
level. The device regulates the FB voltage at a feedback reference voltage,
typically 0.6V.
7
8
FB
EN
Enable control input. A logic-high enables the converter; a logic-low forces the
device into shutdown mode.
Copyright 2017 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS5779A/B-00 October 2017
www.richtek.com
3
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