Datasheet

Table 1. Regulator Enable (EN/UVLO) Jumper JU1 Description
*Default position.
The EV kit includes an EN/UVLO PCB pad and jumper JU1
to enable control of the converter output. An additional
RESETPCBpadisavailableformonitoringtheconverter
output. The VCC PCB pad helps measure the internal LDO
voltage.
Soft-Start Input (SS)
The device utilizes an adjustable soft-start function to
limit inrush current during startup. The soft-start time is
adjustedbythevalueofC3,theexternalcapacitorfrom
SS to GND. To adjust the soft-start time, determine C3
using the following formula:
C3 = 5.55 x t
SS
where t
SS
is the required soft-start time in milliseconds
and C3 is in nanofarads.
Regulator Enable/Undervoltage-Lockout
Level (EN/UVLO)
The device features an EN/UVLO input. For normal
operation,ashuntshouldbeinstalledacrosspins1-2on
jumperJU1.Todisabletheoutput,installashuntacross
pins 2-3 on JU1 and the EN/UVLO pin is pulled to GND.
SeeTable1forJU1settings.
Setting the Undervoltage-Lockout Level
The device offers an adjustable input undervoltage-
lockout level. Set the voltage at which the device turns
on, with a resistive voltage-divider connected from VIN
to GND (see Figure 1). Connect the center node of the
divider to EN/UVLO.
ChooseR1tobe3.3MI and then calculate R2 as follows:
INU
R1 1.218
R2
(V 1.218)
×
=
−
where V
INU
is the voltage at which the IC is required to
turn on. Ensure that V
INU
is higher than 0.8 x V
OUT
.
Adjusting the Output Voltage
The device offers an adjustable output voltage. Set the
output voltage with a resistive voltage-divider connected
from the positive terminal of the output capacitor (V
OUT
)
to GND (see Figure 1). Connect the center node of the
divider to FB/VO
.
Selecttheparallelcombination of R4 and R5, R
P
tobe
less than 30kI. Once R
P
is selected, calculate R4 as
follows:
×
=
P OUT
RV
R4
0.9
Calculate R5 as follows:
×
=
−
OUT
R4 0.9
R5
(V 0.9)
MAX17501H Evaluation Kit
Evaluate: MAX17501H in TDFN Package
3Maxim Integrated
SHUNT POSITION EN/UVLO PIN MAX17501_ OUTPUT
1-2* Connected to IN Enabled
Not installed
Connected to the center node of
resistor-divider R1 and R2
Enabled,UVLOlevelsetthrough
the R1 and R2 resistor-divider
2-3 Connected to GND Disabled