MAXIM MAX1818EVKIT

19-2052; Rev 0; 5/01
MAX1818 Evaluation Kit
Features
♦ +2.5V to +5.5V Input Voltage Range
The EV kit is a fully assembled and tested surfacemount PC board. It can also evaluate other preset voltages and other output voltages in the +1.25V to +5.0V
range by using external resistors.
♦ Output Voltage
+1.8V Fixed Output Voltage (MAX1818EUT18)
+1.25 to +5.0V Adjustable Output Voltage
(External Divider)
♦ Up to 500mA Output Current
♦ Power-OK Output
♦ 6-Pin SOT23 Package
Component List
DESIGNATION
QTY
C1
1
1µF ±10%, 10V X7R ceramic
capacitor (0805)
Taiyo Yuden LMK212BJ105KG
C2
1
4.7µF ±20%, 6.3V X5R ceramic
capacitor (0805)
Taiyo Yuden JMK212BJ475MG or
TDK C2012X5R0J475M
R1
0
Not installed (0603)
R2
0
Not installed, pads shorted with PC
trace (0603)
R3
1
100kΩ ±5% resistor (0603)
♦ Surface-Mount Construction
♦ Fully Assembled and Tested
DESCRIPTION
U1
1
MAX1818EUT18 (6-pin SOT23)
JU1
1
3-pin header
None
1
Shunt
None
1
MAX1818 PC board
None
1
MAX1818 EV kit data sheet
None
1
MAX1818 data sheet
Ordering Information
PART
MAX1818EVKIT
TEMP. RANGE
0°C to +70°C
IC-PACKAGE
6 SOT23
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 connections 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
PHONE
FAX
Taiyo Yuden
408-573-4150
408-573-4159
TDK
847-390-4373
847-390-4428
Note: Please indicate that you are using the MAX1818 when
contacting these component suppliers.
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.
________________________________________________________________ Maxim Integrated Products
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.
1
Evaluates: MAX1818EUT15/18/20/25/33/50
General Description
The MAX1818 linear regulator evaluation kit (EV kit) provides a regulated +1.8V output voltage from a +2.5V to
+5.5V input source. It delivers up to 500mA output current.
Evaluates: MAX1818EUT15/18/20/25/33/50
MAX1818 Evaluation Kit
Detailed Description
The MAX1818 EV kit contains a low-dropout, linear regulator 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.
Table 1. Jumper JU1 Functions
The MAX1818 EV kit features a shutdown mode that
reduces quiescent current to 0.1µA (typ) to preserve
the battery life.
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.
VOUT = VSET (1 + R1 / R2)
R1 = R2 [(VOUT / VSET) - 1]
SHDN
PIN
SHUNT
LOCATION
MAX1818 OUTPUT
1 and 2
Connected to VIN
MAX1818 enabled,
VOUT = +1.8V
2 and 3
Connected to GND
Shutdown mode,
VOUT = 0V
None
Connected external
source to SHDN
pad
MAX1818 output
depends on external
SHDN signal
Table 2. MAX1818 EV Kit Corresponding
Output Voltage
where VSET = 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.
MAX1818 PART
AND SUFFIX
MAX1818 EV KIT FIXED
OUTPUT VOLTAGE
MAX1818EUT15
+1.5V
MAX1818EUT18
+1.8V
MAX1818EUT20
+2.0V
MAX1818EUT25
+2.5V
MAX1818EUT33
+3.3V
MAX1818EUT50
+5.0V
R3
100kΩ
5%
POK
2
POK
OUT
VOUT
+1.8V
6
C2
4.7µF
6.3V
U1
MAX1818EUT18
R1
OPEN
VIN
+2.5V TO +5.5V
GND
GND
1
IN
SET
5
C1
1.0µF
10V
R2
SHORT
1
SHDN
2
3
JU1
3
SHDN
GND
4
Figure 1. MAX1818 EV Kit Schematic
2
_______________________________________________________________________________________
MAX1818 Evaluation Kit
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
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.
Evaluates: MAX1818EUT15/18/20/25/33/50
1.0"