19-2076; Rev 0; 7/01
MAX1724 Evaluation Kit
General Description
Features
The MAX1724 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains
two separate boost switching-regulator circuits. The
left-side circuit contains a MAX1724 with a preset 3.3V
output. Other preset voltages of 2.7V, 3.0V, or 5.0V are
also available. The right-side circuit contains a
MAX1722, which has an adjustable output voltage. This
circuit’s output is set for 3.6V. All devices regulate with
ꢀ 0.91V to V
Input Voltage Range
OUT
ꢀ Two Complete Boost Circuits
3.3V Fixed (MAX1724)
3.6V Adjustable Output (MAX1722)
ꢀ Up to 50mA Output from a 1-Cell Input
Up to 100mA Output from a 2-Cell Input
ꢀ 1.5µA Quiescent Current from V
input voltages from 0.91V to V
, making them ideal
OUT
OUT
for 1- or 2-cell alkaline and NiMH battery applications.
ꢀ Up to 90% Efficiency with Synchronous
The right-side circuit may also be used to evaluate the
MAX1723, which features a shutdown (SHDN) mode.
The MAX1722/MAX1724 has a BATT pin, which lowers
the guaranteed startup voltage from 1.2V to 0.91V.
Rectification
ꢀ Switching Frequency Up to 200kHz
ꢀ All Surface-Mount Design
The MAX1722/MAX1723/MAX1724 feature synchronous
rectification and ultra-low (1.5µA typ) quiescent current
for maximum efficiency and long battery life. Operation
up to 200kHz allows tiny surface-mount components.
ꢀ Fully Assembled and Tested Board
Ordering Information
PART
TEMP. RANGE
IC PACKAGE
MAX1724EVKIT
0°C to +70°C
THIN SOT23-5
Component Suppliers
Component List
DESIGNATION QTY
DESCRIPTION
SUPPLIER
Murata
PHONE
FAX
WEB
814-237-1431 814-238-0490 www.murata.com
847-956-0666 847-956-0702 www.sumida.com
10µF, 10V X7R ceramic capacitors
Taiyo Yuden JMK325BJ106MN
C1–C4
D1
4
0
2
Sumida
Not installed
Taiyo
Yuden
408-573-4150 408-573-4159 www.T-yuden.com
512-794-0081 512-794-0087 www.venkel.com
10µH inductors
Sumida CDR43-100MC
L1, L2
Venkel
Note: Please indicate that you are using the MAX1724 when
contacting these component suppliers.
2M
1ꢀ resistor (0805)
R1
R2
U1
U2
1
1
1
1
Venkel CR0805-10W-2004FT
1.02M 1ꢀ resistor (0805)
Venkel CR0805-10W-1024FT
Quick Start
Maxim MAX1724EZK33
(5-pin THIN SOT23, top mark ADQJ)
The MAX1724 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.
Maxim MAX1722EZK (5-pin THIN
SOT23, top mark ADQF)
3.3V Output (left side):
1) Connect a 0.91V to 3.3V supply to the VBATT pad.
Connect the supply ground to the GND pad.
JU1, JU2
None
2
2
1
3-pin headers
Shunts JU1, JU2
MAX1724 PC board
None
2) Connect a voltmeter to the VOUT pad.
MAX1722/MAX1723/MAX1724 data
sheet
None
None
1
1
3) Verify there is a shunt across pins 1 and 2 of
jumper JU1 (SHDN), thus enabling the MAX1724.
MAX1724 EV kit data sheet
4) Turn on the power supply and verify that the output
is at 3.3V.
Note: Quantities are for both circuits.
________________________________________________________________ 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.