19-2052; Rev 0; 5/01
MAX1818 Evaluation Kit
General Description
The MAX1818 linear regulator evaluation kit (EV kit) pro-
vides a regulated +1.8V output voltage from a +2.5V to
+5.5V input source. It delivers up to 500mA output current.
The EV kit is a fully assembled and tested surface-
mount PC board. It can also evaluate other preset volt-
ages and other output voltages in the +1.25V to +5.0V
range by using external resistors.
o
+2.5V to +5.5V Input Voltage Range
o
Up to 500mA Output Current
o
Output Voltage
+1.8V Fixed Output Voltage (MAX1818EUT18)
+1.25 to +5.0V Adjustable Output Voltage
(External Divider)
o
Power-OK Output
o
6-Pin SOT23 Package
o
Surface-Mount Construction
o
Fully Assembled and Tested
Features
Evaluates: MAX1818EUT15/18/20/25/33/50
Component List
DESIGNATION
C1
QTY
1
DESCRIPTION
1µF
±10%,
10V X7R ceramic
capacitor (0805)
Taiyo Yuden LMK212BJ105KG
4.7µF
±20%,
6.3V X5R ceramic
capacitor (0805)
Taiyo Yuden JMK212BJ475MG or
TDK C2012X5R0J475M
Not installed (0603)
Not installed, pads shorted with PC
trace (0603)
100kΩ
±5%
resistor (0603)
MAX1818EUT18 (6-pin SOT23)
3-pin header
Shunt
MAX1818 PC board
MAX1818 EV kit data sheet
MAX1818 data sheet
Ordering Information
PART
MAX1818EVKIT
TEMP. RANGE
0°C to +70°C
IC-PACKAGE
6 SOT23
C2
1
R1
R2
R3
U1
JU1
None
None
None
None
0
0
1
1
1
1
1
1
1
Note:
To evaluate the MAX1818EUT15, /20, /25, /33, or /50,
request a MAX1818EUT15, /20, /25, /33, or /50 free sample with
the MAX1818 EV kit. Refer to soldering information in Absolute
Maximum Rating section of MAX1818 data sheet for mass
production solder reflow advice.
Quick Start
The MAX1818 EV Kit is fully assembled and tested.
Follow these steps to verify board operation.
Do not turn on the power supply until all connec-
tions are completed.
1) Verify that the shunt is across pins 1 and 2 of
jumper JU1 (SHDN) (Table 1).
2) Connect a voltmeter to the VOUT pad. Connect the
ground to the GND pad closest to VOUT.
Component Suppliers
SUPPLIER
Taiyo Yuden
TDK
PHONE
408-573-4150
847-390-4373
FAX
408-573-4159
847-390-4428
3) Connect a +2.5V to +5.5V supply to the VIN pad.
Connect the supply ground to the GND pad closest
to VIN.
4) Turn on the power supply, and verify that the output
is the preset voltage: +1.8V.
To evaluate other voltages, refer to
Evaluating Other
Output Voltages.
Note:
Please indicate that you are using the MAX1818 when
contacting these component suppliers.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX1818 Evaluation Kit
Evaluates: MAX1818EUT15/18/20/25/33/50
Detailed Description
The MAX1818 EV kit contains a low-dropout, linear reg-
ulator circuit, which provides a +1.8V output from a
+2.5V to +5.5V input voltage. The EV kit provides up to
500mA output current. Power-OK will provide a logical
low output when the output voltage falls below 93% of
its nominal voltage.
The MAX1818 EV kit features a shutdown mode that
reduces quiescent current to 0.1µA (typ) to preserve
the battery life.
Table 1. Jumper JU1 Functions
SHUNT
LOCATION
1 and 2
2 and 3
SHDN
PIN
Connected to VIN
Connected to GND
Connected external
source to
SHDN
pad
MAX1818 OUTPUT
MAX1818 enabled,
V
OUT
= +1.8V
Shutdown mode,
V
OUT
= 0V
MAX1818 output
depends on external
SHDN
signal
Evaluating Other Output Voltages
The output voltage of the MAX1818 EV kit is preset to
+1.8V. To generate an output voltage other than the
preset output voltage, cut open the PC trace shorting
R2, and install feedback resistors R1 and R2. Select R2
in the 25kΩ to 100kΩ range.
V
OUT
= V
SET
(1 + R1 / R2)
R1 = R2 [(V
OUT
/ V
SET
) - 1]
where V
SET
= 1.25V.
The MAX1818 EV kit can also be used to evaluate the
MAX1818EUT15, /20, /25, /33, or /50. Replace
MAX1818EUT18 with a MAX1818EUT15, /20, /25, /33,
or /50. Hand soldering for single unit evaluation on the
EV kit is acceptable. Table 2 lists the corresponding
output voltage.
None
Table 2. MAX1818 EV Kit Corresponding
Output Voltage
MAX1818 PART
AND SUFFIX
MAX1818EUT15
MAX1818EUT18
MAX1818EUT20
MAX1818EUT25
MAX1818EUT33
MAX1818EUT50
MAX1818 EV KIT FIXED
OUTPUT VOLTAGE
+1.5V
+1.8V
+2.0V
+2.5V
+3.3V
+5.0V
R3
100kΩ
5%
POK
2
POK
U1
MAX1818EUT18
OUT
6
C2
4.7µF
6.3V
R1
OPEN
VOUT
+1.8V
GND
VIN
+2.5V TO +5.5V
C1
1.0µF
10V
1
IN
SET
5
R2
SHORT
GND
1
SHDN
2
3
JU1
3
4
SHDN
GND
Figure 1. MAX1818 EV Kit Schematic
2
_______________________________________________________________________________________
MAX1818 Evaluation Kit
Evaluates: MAX1818EUT15/18/20/25/33/50
1.0"
Figure 2. MAX1818 EV Kit Component Placement Guide—
Component Side
1.0"
Figure 3. MAX1818 EV Kit PC Board Layout—Component Side
1.0"
Figure 4. MAX1818 EV Kit PC Board Layout—Solder Side
1.0"
Figure 5. MAX1818 EV Kit Component Placement Guide—
Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
3
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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