RT7278
Ordering Information
RT7278
Pin Configurations
(TOP VIEW)
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
8
7
6
5
EN
FB
VIN
2
3
4
BOOT
SW
GND
PVCC
SS
Lead Plating System
G : Green (Halogen Free and Pb Free)
9
GND
Note :
SOP-8 (Exposed Pad)
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Functional Pin Description
Pin No.
Pin Name
Pin Function
Enable Control Input. A logic-high enables the converter; a logic-low forces
the IC into shutdown mode reducing the supply current to less than 10μA.
1
EN
Feedback Voltage Input. It is used to regulate the output of the converter to a
set value via an external resistive voltage divider. The feedback threshold
voltage is 0.765V typically.
2
3
4
FB
Regulator Output for Internal Circuit. Connect a 1μF capacitor to GND to
stabilize output voltage.
PVCC
SS
Soft-Start Time Setting. SS controls the soft-start period. Connect a capacitor
from SS to GND to set the soft-start period. A 3.9nF capacitor sets the
soft-start period of VOUT to 2.6ms.
5, 9
(Exposed Pad)
Ground. The Exposed pad should be soldered to a large PCB and connected
to GND for maximum thermal dissipation.
GND
SW
6
Switch Node. Connect this pin to an external L-C filter.
Bootstrap Supply for High Side Gate Driver. Connect a 0.1μF or greater
ceramic capacitor from BOOT to SW pins.
7
BOOT
Power Input. The input voltage range is from 4.5V to 18V. Must bypass with a
suitably large ( ≥10μF x 2) ceramic capacitor.
8
VIN
Copyright 2013 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS7278-00 January 2013
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
