EN2340QI
PIN
NAME I/O
FUNCTION
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 29-34.
29-34
PGND
G
35-41
42
PVIN
P
Internal 3V linear regulator output. Connect this pin to AVIN (Pin 51) for applications where
operation from a single input voltage (PVIN) is required. If AVINO is being used, place a
1µF, X5R/X7R, capacitor between AVINO and AGND as close as possible to AVINO.
AVINO
O
43
44
PG
BTMP
I/O Place a 0.1µF, X5R/X7R, capacitor between this pin and BTMP.
I/O See pin 43 description.
Internal regulated voltage used for the internal control circuitry. Place a 1.0µF, X7R,
capacitor between this pin and BGND.
See pin 45 description.
45
46
47
48
49
VDDB
BGND
S_IN
O
G
I
Digital Input. This pin accepts either an input clock to phase lock the internal switching
frequency or a S_OUT signal from another EN2340QI. Leave this pin floating if not used.
Digital Output. PWM signal is output on this pin. Leave this pin floating if not used.
Power OK is an open drain transistor (pulled up to AVIN or similar voltage) used for power
system state indication. POK is logic high when VOUT is within -10% of VOUT nominal.
Input Enable. Applying a logic high to this pin enables the output and initiates a soft-start.
Applying a logic Low disables the output. Do not leave floating.
3.3V Input power supply for the controller. Place a 0.1µF, X7R, capacitor between AVIN
and AGND.
Analog Ground. This is the Ground return for the controller. Needs to be connected to a
quiet ground.
S_OUT
POK
O
O
50
51
ENABLE
AVIN
I
P
G
52, 53,
60
AGND
External Feedback Input. The feedback loop is closed through this pin. A voltage divider at
54
VFB
I/O VOUT is used to set the output voltage. The mid-point of the divider is connected to VFB. A
phase lead capacitor from this pin to VOUT is also required to stabilize the loop.
55
56
EAOUT
SS
O
Optional Error Amplifier output. Allows for customization of the control loop.
Soft-Start node. The soft-start capacitor is connected between this pin and AGND. The
value of this capacitor determines the startup time.
I/O
Programmable over-current protection. Placement of a resistor on this pin will adjust the
57
RCLX
I/O over-current protection threshold. See Table 2 for the recommended RCLX Value to set
OCP at the nominal value specified in the Electrical Characteristics table.
Adding a resistor (RFS) to this pin will adjust the switching frequency of the EN2340QI. See
I/O Table 1 for suggested resistor values on RFS for various PVIN/VOUT combinations to
maximize efficiency. Do not leave floating.
58
69
FADJ
Not a perimeter pin. Device thermal pad to be connected to the system GND plane for heat-
sinking purposes.
PGND
©Enpirion 2012 all rights reserved, E&OE
Enpirion Confidential
www.enpirion.com, Page 3
06878
April 16, 2012
Rev: B
ENPIRION [ ENPIRION, INC. ]
