en5311 Enpirion, en5311 Datasheet - Page 2

• Manufacturer Part Number: en5311
• Description: 1a Synchronous Buck Regulator With Integrated Inductor
• Manufacturer: Enpirion

March 2008
Pin Description
V
to the IC. VIN can range from 2.4V to 5.5V.
Input GND: (Pin 3): Input power ground.
Connect this pin to the ground terminal of the
input
Recommendations for further details.
Output GND: (Pin 4): Power ground.
output filter capacitor should be connected
between this pin and V
recommendations for further detail.
V
NC
should not be electrically connected to each
other or to any external signal, voltage, or
©Enpirion 2008 all rights reserved, E&OE
Figure 2. Pin description, top view.
IN
OUT
(Pin 1,2): Input voltage pin. Supplies power
(Pin 5,6,7): Regulated output voltage.
(Pin
capacitor.
8,9,10,11,12,13,14):
OUT
Refer
. Refer to Layout
These
to
Layout
pins
The
2
ground. One or more of these pins may be
connected internally.
V
regulation.
voltage rail as close to the terminal of the
output filter capacitor as possible.
V
option. When using the external divider option
(VS0=VS1=VS2= high) connect this pin to the
center of the external divider. Set the divider
such that V
VS0,VS1,VS2 (Pin 17,18,19): Output voltage
select. VS0=pin19, VS1=pin18, VS2=pin17.
Selects one of seven preset output voltages or
choose external divider by connecting pins to
logic high or low. Logic low is defined as V
≤ 0.4V. Logic high is defined as V
Any level between these two values is
indeterminate.
ENABLE (Pin 20): Output enable. Enable =
logic high, disable = logic low. Logic low is
defined as V
as V
values is indeterminate.
Bottom Thermal Pad: Device thermal pad to
remove heat from package. Connect to PCB
surface ground pad and PCB internal ground
plane (see layout recommendations).
SENSE
FB
(Pin 16): Feed back pin for external divider
HIGH
(Pin 15): Sense pin for output voltage
≥ 1.4V. Any level between these two
FB
LOW
= 0.603V.
Connect V
≤ 0.2V. Logic high is defined
SENSE
www.enpirion.com
to the output
HIGH
EN5311QI
≥ 1.4V.
LOW