MAXIM MAX1835EVKIT

19-1920; Rev 1; 7/01
MAX1833 Evaluation Kit
The MAX1833 evaluation kit (EV kit) evaluates the
MAX1833 high-efficiency, step-up DC-DC converter for
portable hand-held devices. The EV kit accepts a positive input voltage between 1.5V to VOUT and converts it
to a 3.3V output for currents up to 150mA. The EV kit
provides ultra-low quiescent current and high efficiency
for maximum battery life.
The MAX1833 EV kit is a fully assembled and tested
surface-mount printed circuit board. It can also be used
to evaluate the MAX1832/MAX1834/MAX1835 for other
output voltages in the 2V to 5.5V range. Additional pads
on the board accommodate the external feedback
resistors for setting different output voltages.
Features
♦ Reverse-Battery Protection
♦ 1.5V to VOUT Input Supply Voltage
♦ 3.3V Output Voltage (MAX1833/MAX1835)
♦ Adjustable Output Voltage (MAX1832/MAX1834,
2V to 5.5V)
♦ Up to 150mA Output Current
♦ No External Schottky Diode Required
♦ Synchronous Rectification for Improved
Efficiency
♦ 1µA IC Shutdown Current
♦ RST Output (MAX1833/MAX1835)
♦ 6-Pin SOT23 Package
♦ Surface-Mount Construction
♦ Fully Assembled and Tested
Component List
DESIGNATION
QTY
DESCRIPTION
Ordering Information
PART
TEMP. RANGE
MAX1833EVKIT
0°C to +70°C
IC PACKAGE
6 SOT23
C1, C2
2
10µF, 6.3V X5R ceramic
capacitors (1206)
Taiyo Yuden JMK325BJ106MN
or
TDK C3225X5R1A106M
C3
1
0.01µF ceramic capacitor (0805)
JU1
1
3-pin header
PART
L1
1
10µH power inductor
Sumida CDRH5D18-100
OUTPUT
VOLTAGE
MAX1832EUT
Adjustable
VBATT
R1
1
309kΩ ±1% resistor (0805)
MAX1833EUT
Fixed 3.3V
VBATT
R2
0
Not installed (0805)
MAX1834EUT
Adjustable
VBATT - 0.7V
R3
1
1MΩ ±5% resistor (0805)
MAX1835EUT
Fixed 3.3V
VBATT - 0.7V
R4
1
220kΩ ±5% resistor (0805)
U1
1
MAX1833EUT (6-pin SOT23)
None
1
Shunt
None
1
MAX1833 PC board
None
1
MAX1832−MAX1835 data sheet
None
1
MAX1833EVKIT data sheet
Note: To evaluate the MAX1832/MAX1834/MAX1835, request a
MAX1832EUT-T/MAX1834EUT-T/MAX1835EUT-T free sample
with the MAX1833EVKIT.
Selector Guide
VOUT IN
SHUTDOWN
Component Suppliers
SUPPLIER
Sumida
Taiyo Yuden
TDK
PHONE
847-956-0666
408-573-4150
847-390-4373
FAX
847-956-0702
408-573-4159
847-390-4428
Note: Please indicate that you are using the MAX1832,
MAX1833, MAX1834, or MAX1835 when contacting these
component suppliers
________________________________________________________________ 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: MAX1832–MAX1835
General Description
Evaluates: MAX1832–MAX1835
MAX1833 Evaluation Kit
Quick Start
Table 1. Jumper JU1 Functions
The MAX1833 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below to verify
board operation. Do not turn on the power supply
until all connections are completed:
1) Connect a voltmeter and load (if any) to the VOUT
pad.
SHDN PIN
MAX1833
OUTPUT
1 and 2
Connected to
VOUT
MAX1833
enabled,
VOUT = 3.3V
2 and 3
Connected to
GND
Shutdown
mode,
VOUT = VBATT
SHUNT LOCATION
2) Verify that the shunt is across JU1 pins 1 and 2.
3) Connect the input supply (1.5V to 3.3V) to the pads
marked VBATT and GND.
4) Turn on the power and verify that the output voltage
is 3.3V.
5) Refer to the Setting the Output Voltage section in
the MAX1832–MAX1835 data sheet to modify the
board for a different output voltage.
Detailed Description
Shutdown Jumper Selection
The MAX1833 EV kit features a shutdown mode that
reduces quiescent current to <1µA to preserve battery
life. In shutdown, the MAX1833 (and MAX1832) output
connects to the battery input voltage through the inductor and the internal synchronous rectifier PFET.
Evaluating Other Output Voltages
(MAX1832/MAX1834)
The MAX1833EVKIT output is set to +3.3V. However,
the MAX1832/MAX1834 can be used to evaluate other
output voltages in the +2V to +5.5V range. Replace the
MAX1833 device with a MAX1832 or MAX1834, and
select feedback resistors R1 and R2 values. Select
feedback resistor R2 in the 100kΩ to 1MΩ range. R1 is
then given by:
R1 = R2 ((VOUT / VFB) - 1)
where VFB = 1.228V.
Care must be taken when installing the IC. Refer to the
MAX1832–MAX1835 data sheet for soldering instructions and limitations.
VBATT
1.5V TO 3.3V
L1
10µH
2
VOUT
SHDN
1
2
BATT
R4
220kΩ
JU1
3
R3
1MΩ
LX
C2
10µF
6.3V
4
U1
MAX1832
1
SHDN MAX1833
MAX1834
C3
MAX1835
0.01µF
GND
3
OUT
5
R1
309kΩ
1%
RST
(FB)
C1
10µF
6.3V
6
RST
R2
OPEN
( ) ARE FOR MAX1832/MAX1834 ONLY.
Figure 1. MAX1833 EV Kit Schematic
2
VOUT
3.3V
_______________________________________________________________________________________
GND
MAX1833 Evaluation Kit
Figure 2. MAX1833 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX1833 EV Kit PC Board Layout—Component Side
ACTUAL BOARD SIZE: 1.9in ✕ 1.9in
Figure 4. MAX1833 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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 3
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
Evaluates: MAX1832–MAX1835
ACTUAL BOARD SIZE: 1.9in ✕ 1.9in
ACTUAL BOARD SIZE: 1.9in ✕ 1.9in