19-1917; Rev 0; 1/01
MAX1605 Evaluation Kit
General Description
The MAX1605 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains a
boost switching converter that generates a positive volt-
age to drive low-power LCD displays. The circuit is
configured for a +18V output voltage and provides up
to 30mA. Higher output voltages are possible by select-
ing different components.
The IC operates from a +2.4V to +5.5V supply voltage
but can boost battery voltages as low as +0.8V up to
+30V at the output. Three different inductor current lim-
its can be evaluated with the EV kit as configured.
The MAX1605 EV kit demonstrates low quiescent cur-
rent and high efficiency up to 88% for maximum battery
life. Operation up to 500kHz allows the use of tiny sur-
face-mount components.
o
Input Voltage
+0.8V to +18V (as configured)
+2.4V to +5.5V (IC V
CC
)
o
Output Voltage
+18V Output Up to 30mA (as configured)
o
Output Voltage Adjustable with Resistors
o
Adjustable Inductor Current-Limit Setting
o
Internal MOSFET Switches
o
1µA (typ) IC Shutdown Current
o
Switching Frequency Up to 500kHz
o
Surface-Mount Components
o
Fully Assembled and Tested
Features
Evaluates: MAX1605
Component List
DESIGNATION
C1
C2, C3
C4
QTY
1
2
1
DESCRIPTION
0.1µF, 16V, X7R ceramic cap (0603)
Taiyo Yuden EMK107BJ104KA
1.0µF, 25V, X7R ceramic caps (1206)
Taiyo Yuden TMK316BJ105KL
10pF, 50V ceramic cap (0603)
Taiyo Yuden UMK107CG100DZ
500mA, 30V Schottky diode
(SOD-123)
Nihon EP05Q03L or
Toshiba CRS02
10µH, 700mA inductor
Sumida CR32-100
2.2MΩ
±1%
resistor (0805)
165kΩ
±1%
resistor (0805)
MAX1605EUT (6-pin SOT23)
3-pin headers
Shunts (JU1, JU2)
MAX1605 PC board
MAX1605 data sheet
MAX1605 EV kit data sheet
SUPPLIER
Nihon USA
Sumida
Taiyo Yuden
Toshiba
PART
MAX1605EVKIT
Ordering Information
TEMP. RANGE
0°C to +70°C
IC PACKAGE
6 SOT23-6
Component Suppliers
PHONE
661-867-2555
847-956-0666
408-573-4150
949-455-2000
FAX
661-867-2698
847-956-0702
408-573-4159
949-859-3963
D1
1
L1
R1
R2
U1
JU1, JU2
None
None
None
None
1
1
1
1
2
2
1
1
1
Note:
Please indicate that you are using the MAX1605 when
contacting these component suppliers.
Quick Start
The MAX1605 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) Connect a +0.8V to +18V DC power supply to the VIN
pad. Connect the supply ground to the GND pad (or
use the same supply and limits as in step 2).
2) Connect a +2.4V to +5.5V DC power supply to the
VCC pad. Connect the supply ground to the GND
pad.
3) Verify that shunts are across pins 1 and 2 of
jumpers JU1 (SHDN) and JU2 (LIM, 500mA).
________________________________________________________________
Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX1605 Evaluation Kit
Evaluates: MAX1605
4) Turn on the VCC power supply, followed by the
VIN power-supply. Power-supply sequencing is not
critical.
5) Verify that the output (VOUT) is +18V.
For instructions on selecting the feedback resistors for
other output voltages, refer to the
Evaluating Other
Output Voltages
section in this document.
Inductor Current Limit
The MAX1605 EV kit features options for evaluating
several different inductor current limits.
The 3-pin jumper, JU2 selects the inductor current limit
for the MAX1605 EV kit. Table 2 lists the selectable
jumper options.
Detailed Description
The MAX1605 evaluation kit (EV kit) is a fully assem-
bled and tested surface-mount circuit board that con-
tains a boost switching converter, generating +18V
used to drive low power LCD displays. The circuit pro-
vides up to 30mA of current to the EV kit’s output.
Higher output voltages up to +30V are possible by
selecting different feedback resistors.
Power for the converter circuit can be supplied from a
+0.8V to V
OUT
DC source or a multiple-cell lithium-ion
(Li+) battery. The IC requires a +2.4V to +5.5V DC
source. The IC can also be powered from the convert-
er’s input supply if the input voltage is limited to
between +2.4V and +5.5V.
Three different inductor current limits can be evaluated
with the EV kit (125mA, 250mA, and 500mA) by chang-
ing a jumper position.
The MAX1605 EV kit demonstrates low quiescent cur-
rent (18µA I
CC
operating current) and high efficiency
up to 88% for maximum battery life.
Table 2. Jumper JU2 Function
SHUNT
LOCATION
1 and 2
2 and 3
None
LIM PIN
Connected to VCC
Connected to GND
Floating
INDUCTOR
CURRENT LIMIT
500mA
125mA
250mA
Evaluating Other Output Voltages
Output
The MAX1605 EV kit’s boost converter output (VOUT) is
set to +18V by two feedback resistors (R1, R2). To gen-
erate output voltages other than +18V (+0.8V to +30V),
select different voltage-divider resistors (R1, R2).
Capacitor C3 must be rated for higher than V
OUT
.
Refer to the
Setting the Output Voltages
section in the
MAX1605 data sheet for instructions on selecting the
resistors. The output voltage (V
OUT
) is determined by
the following equation:
V
OUT
= V
FB
((R1/R2) + 1)
where V
FB
= 1.25V.
Jumper Selection
Shutdown Mode
The MAX1605 EV kit features a shutdown mode that
reduces the MAX1605 shutdown current to less than
0.1µA, thus preserving battery life. The 3-pin jumper,
JU1, selects the shutdown mode for the MAX1605.
Table 1 lists the selectable jumper options.
Single-Supply Operation
VIN and VCC
The MAX1605 EV kit can be operated from a single
power supply. To evaluate the EV kit with a single sup-
ply, connect a jumper wire from the VIN pad to the VCC
pad. Connect a +2.4V (min) to +5.5V (max) power sup-
ply to the VIN or VCC pad.
Table 1. Jumper JU1 Functions
SHUNT
LOCATION
1 and 2
SHDN
PIN
MAX1605 OUTPUT
MAX1605 enabled,
V
OUT
= +18V
(as configured)
Shutdown mode,
V
OUT
= V
IN
- V
DIODE
Connected to VIN
2 and 3
Connected to GND
2
_______________________________________________________________________________________
MAX1605 Evaluation Kit
Evaluates: MAX1605
L1
10µH
VIN
C2
1.0µF
GND
JU1
SHDN
2
3
1
1
SHDN
LX
4
VCC
JU2
R1
2.2M
1%
C4
10pF
C3
1.0µF
D1
VOUT
GND
U1
MAX1605
VCC
2
V
CC
LIM
5
1
2
3
R2
165k
1%
C1
0.1µF
3
GND
FB
6
Figure 1. MAX1605 EV Kit Schematic
_______________________________________________________________________________________
3
MAX1605 Evaluation Kit
Evaluates: MAX1605
ACTUAL BOARD DIMENSIONS:
2.4in x 1.9in
Figure 2. MAX1605 EV Kit Component Placement Guide—
Component Side
ACTUAL BOARD DIMENSIONS:
2.4in x 1.9in
Figure 3. MAX1605 EV Kit PC Board Layout—Component Side
ACTUAL BOARD DIMENSIONS:
2.4in x 1.9in
Figure 4. MAX1605 EV Kit PC Board Layout—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.
4
_____________________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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