EN6347QI3 ENPIRION [Enpirion, Inc.], EN6347QI3 Datasheet - Page 2

• Manufacturer Part Number: EN6347QI3
• Description: 4A Voltage Mode Synchronous Buck PWM DC-DC Converter with Integrated Inductor
• Manufacturer: ENPIRION [Enpirion, Inc.]

Ordering Information
Pin Description
¤Enpirion 2011 all rights reserved, E&OE
Figure 2: Typical Application Schematic (PWM mode)
EN6347QI
EN6347QI3
EN6347QI-E
PIN
1-2, 12,
Part Number
34-38
22-25
13-18
19-21
05991
5-11
3-4,
26
27
28
29
30
31
32
33
39
LLM/SYNC
ENABLE
NC(SW)
NAME
PGND
AGND
PGND
VOUT
RLLM
PVIN
AVIN
POK
VFB
NC
SS
Temp Rating
-40 to +85
-40 to +85
(°C)
QFN Evaluation Board
NO CONNECT – These pins are internally connected to the common switching node of the
internal MOSFETs. They are not to be electrically connected to any external signal, ground,
or voltage. Failure to follow this guideline may result in damage to the device.
NO CONNECT – These pins may be internally connected. Do not connect to each other or
to any other electrical signal. Failure to follow this guideline may result in device damage.
Regulated converter output. Connect these pins to the load and place output capacitor
between these pins and PGND pins 13-15.
Input/Output power ground. Connect these pins to the ground electrode of the input and
output filter capacitors. See VOUT and PVIN pin descriptions for more details.
Input power supply. Connect to input power supply. Decouple with input capacitor to
PGND pins 16-18.
Dual function pin providing LLM Enable and External Clock Synchronization (see
Application Section). At static Logic HIGH, device will allow automatic engagement of light
load mode. At static logic LOW, the device is forced into PWM only. A clocked input to this
pin will synchronize the internal switching frequency to the external signal. If this pin is left
floating, it will pull to a static logic high, enabling LLM.
Input Enable. Applying logic high enables the output and initiates a soft-start. Applying
logic low disables the output.
Power OK is an open drain transistor used for power system state indication. POK is logic
high when VOUT is within -10% of VOUT nominal.
Programmable LLM engage resistor to AGND allows for adjustment of load current at which
Light-Load Mode engages. Can be left open for PWM only operation.
Soft-Start node. The soft-start capacitor is connected between this pin and AGND. The
value of this capacitor determines the startup time.
External Feedback Input. The feedback loop is closed through this pin. A voltage divider at
VOUT is used to set the output voltage. The midpoint of the divider is connected to VFB. A
phase lead capacitor from this pin to VOUT is also required to stabilize the loop.
Analog Ground. This is the controller ground return. Connect to a quiet ground.
Input power supply for the controller. Connect to input voltage at a quiet point.
Device thermal pad to be connected to the system GND plane. See Layout
Recommendations section.
38-pin QFN T&R
38-pin QFN T&R
Package
10/04/2011
Pin Assignments (Top View)
2
FUNCTION
NOTE: All pins must be soldered to PCB.
Figure 3: Pinout Diagram (Top View)
www.enpirion.com
EN6347QI
Rev: B