en5311qi-e Enpirion, en5311qi-e Datasheet - Page 2

• Manufacturer Part Number: en5311qi-e
• Description: 1a Synchronous Buck Regulator With Integrated Inductor
• Manufacturer: Enpirion

Pin Description
VIN (Pin 1,2): Input voltage pin.
power to the IC.
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.
VOUT (Pin 5,6,7): Regulated output voltage.
NC
should not be electrically connected to each
other or to any external signal, voltage, or
©Enpirion 2009 all rights reserved, E&OE
03799
Figure 2. Pin description, top view.
(Pin
capacitor.
8,9,10,11,12,13,14):
OUT
Refer
. Refer to Layout
These
to
Supplies
Layout
pins
The
11/24/2009
2
ground. One or more of these pins may be
connected internally.
VSENSE (Pin 15):
voltage regulation.
output voltage rail as close to the terminal of
the output filter capacitor as possible.
VFB (Pin 16): Feed back pin for external
divider 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).
HIGH
≥ 1.4V. Any level between these two
LOW
≤ 0.2V. Logic high is defined
FB
= 0.603V.
Connect V
Sense pin for output
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SENSE
HIGH
EN5311QI
≥ 1.4V.
to the
Rev:B
LOW