EP5348UI-E Enpirion, EP5348UI-E Datasheet - Page 8

• Manufacturer Part Number: EP5348UI-E
• Description: Power Management Development Tools EP5348UI Eval Board 400mA/5MHz Buck Reg
• Manufacturer: Enpirion
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EP5348UI-E

• Product: Power Management Development Tools
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: EP5348UI

MOSFET which is compared to a reference
current. When this level is exceeded the P-
FET is turned off and the N-FET is turned on,
pulling V
for approximately 0.5mS and then a normal
soft start is initiated.
condition still persists, this cycle will repeat.
Under Voltage Lockout
During initial power up an under voltage
lockout circuit will hold-off the switching
circuitry until the input voltage reaches a
sufficient level to ensure proper operation. If
the voltage drops below the UVLO threshold,
the lockout circuitry will disable the switching.
Hysteresis is included to prevent chattering
between states.
Application Information
Output Voltage Programming
The EP5348UI uses a simple resistor divider to
program the output voltage.
Referring to Figure 3, use 200 kΩ, 1% or better
for the upper resistor (R
bottom resistor (R
©Enpirion 2011 all rights reserved, E&OE
05721
R
B
=
Figure 3: Typical Application Circuit
OUT
(
V
VFB
OUT
low. This condition is maintained
−
*
VFB
R
B
A
) in kΩ is given as:
)
VFB
A
If the over current
). The value of the
=
0
6 .
V
nominal
6/15/2011
8
Enable
The ENABLE pin provides a means to shut
down
operation.
converter and cause it to shut down. A logic
high will enable the converter into normal
operation.
NOTE:
floating.
Thermal Shutdown
When excessive power is dissipated in the
chip, the junction temperature rises. Once the
junction temperature exceeds the thermal
shutdown threshold, the thermal shutdown
circuit turns off the converter output voltage
thus allowing the device to cool. When the
junction temperature decreases by 15C°, the
device will go through the normal startup
process.
A 5pF MLCC capacitor C
parallel with R
Input Filter Capacitor
C
The input capacitor must use a X5R or X7R or
equivalent dielectric formulation.
equivalent
capacitance with frequency, bias, and with
temperature, and are not suitable for switch-
mode DC-DC converter input filter applications.
Output Filter Capacitor
C
when 4.5V ≤ V
C
cases.
always be improved by adding a second 2.2uF
or 1uF output capacitor for any operating
condition.
V
capacitor next to the EP5348UI. Any additional
bulk capacitance for load decoupling and
byass has to be far enough from the V
OUT
IN_MIN
OUT_MIN
OUT_MIN
has to be sensed at the last output filter
= 2.2µF 0603 case size or larger.
the
However,
= 10uF 0603 MLCC for all other use
= 10uF 0603 + 2.2uF 0603 MLCC
The ENABLE pin must not be left
converter
A logic low will disable the
A
dielectric
IN
for compensation.
≤ 5.5V, AND I
ripple
A
or
is also required in
formulations
www.enpirion.com
performance
OUT
enable
> 300mA.
EP5348UI
Y5V or
normal
lose
Rev: B
can
OUT