19-2517; Rev. 0; 7/02
MAX1702 Evaluation Kit
General Description
The MAX1702 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that demonstrates
the MAX1702B power-management IC. The IC is opti-
mized for microprocessor-based applications. The
MAX1702B integrates three high-performance step-down
DC-DC power supplies with associated supervisory and
management functions. The first power supply (VI/O) is
configured for 3.3V and provides up to 900mA. The sec-
ond power supply (VCORE) is configured for 1.1V and
provides up to 400mA. The third power supply (VMEM)
can be configured to 1.8V, 2.5V, or 3.3V and provides up
to 800mA. Power management functions include auto-
matic power-up sequencing, power-on reset, manual
reset with timer, and two levels of low-battery detection.
The EV kit operates with a 2.6V to 5.5V input voltage
range, allowing the use of batteries or a regulated DC
power supply at the input.
Features
o
Triple-Output Power Supply
3.3V VI/O Peripheral Output
1.1V VCORE µP Core Output
1.8V, 2.5V, or 3.3V Selectable VMEM Memory
Output
o
Internal Switches
o
1MHz Pulse-Width Modulation (PWM) Switching
o
Adjustable Dead/Low-Battery Settings
o
900mA Available from the VI/O Output
o
800mA Available from the VMEM Output
o
400mA Available from the VCORE Output
o
Surface-Mount Construction
o
Fully Assembled and Tested
Evaluates: MAX1702B
Ordering Information
PART
MAX1702EVKIT
TEMP RANGE
0°C TO +70°C
IC PACKAGE
36 QFN (6mm
×
6 mm)
Component List
DESIGNATION QTY
DESCRIPTION
4.7µF ±20%, 6.3V X5R
ceramic capacitor (0805)
TDK C2012X5R0J475KT or
Taiyo Yuden JMK212BJ475MG
10µF ±10%, 6.3V X5R
ceramic capacitors (1206)
TDK C3216X5R0J106KT or
Taiyo Yuden JMK316BJ106KL
1000pF ±10%, 50V X7R
ceramic capacitors (0603)
TDK C1608X7R1H102KT or
Taiyo Yuden UMK107CG102KZ
680pF ±10%, 50V X7R
ceramic capacitor (0603)
TDK C1608X7R1H681KT or
Taiyo Yuden UMK107CG681KZ
0.1µF ±10%, 16V X7R
ceramic capacitor (0603)
TDK C1608X7R1C104KT or
Taiyo Yuden EMK107BJ104KA
DESIGNATION QTY
C9
C10, C12, C14
C11, C13,
C15, C16
0
3
DESCRIPTION
Not installed, capacitor (1210)
1.0µF ±10%, 10V X5R
ceramic capacitors (0603)
TDK C1608X5R1A105K
Not installed, capacitors (0603)
33pF ±5%, 50V COG
ceramic capacitors (0603)
TDK C1608COG1H330JT or
Taiyo Yuden UMK107CG330JZ
3-pin header
4-pin header
4.7µH, 1.32A inductors
Sumida CDRH4D28-4R7
4.7µH, 900mA inductor
Sumida CDRH3D16-4R7NC
267kΩ
±1%
resistor (0603)
90.9kΩ
±1%
resistor (0603)
137kΩ
±1%
resistor (0603)
C1
1
C2, C3,
C4, C17
0
4
C18, C19, C20
3
C5, C7
2
JU1
JU2
L1, L3
L2
R1
R2
R3
1
1
2
1
1
1
1
C6
1
C8
1
________________________________________________________________
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.
MAX1702 Evaluation Kit
Evaluates: MAX1702B
Component List (continued)
DESIGNATION QTY
R4
R5
R6
R7
R8
R9–R12
R13
SW1
U1
—
—
—
—
1
1
1
1
1
4
1
1
1
2
1
1
1
DESCRIPTION
33kΩ
±5%
resistor (0603)
8.06kΩ
±1%
resistor (0603)
14kΩ
±1%
resistor (0603)
18kΩ
±5%
resistor (0603)
22kΩ
±5%
resistor (0603)
100kΩ
±5%
resistors (0603)
1Ω
±5%
resistor (0603)
Momentary contact switch
MAX1702BEGX
(36-pin QFN, 6mm x 6mm)
Shunts (JU1, JU2)
MAX1702 PC board
MAX1702B data sheet
MAX1702 EV kit data sheet
7) Turn on the power supply and verify that the VI/O
output is at 3.3V, VCORE output is at 1.1V, and
VMEM output is at 2.5V.
8) Use a voltmeter to verify that
LBO,
OUTOK, and
RSO
are at 3.3V and REF is at 1.25V.
Detailed Description
The MAX1702 EV kit is a fully assembled and tested
surface-mount circuit board that demonstrates the
capability of the MAX1702B triple-output step-down
DC-DC converter optimized for microprocessor-based
applications. The MAX1702B integrates three high-per-
formance, 1MHz PWM switching, step-down DC-DC
power supplies. These power supplies can be used to
power the microprocessor, memory, and I/O peripher-
als in a single system. The microprocessor VCORE
supply is configured for 1.1V and provides up to
400mA. The memory VMEM supply is configurable to
1.8V, 2.5V, or 3.3V and provides up to 800mA. The I/O
peripheral VI/O supply is configured for 3.3V and pro-
vides up to 900mA. The VPLL output is a filtered output
from VCORE that can be used to supply noise-sensitive
circuitry such as a phase-lock loop.
The EV kit input voltage range is 2.6V to 5.5V and requires
up to 2A of current from the source with all outputs fully
loaded.
Quick Start
The MAX1702 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below for board
operation.
Do not turn on the power supply until all
connections are completed:
1) Verify that a shunt is across pins 1 and 2 of jumper
JU1 (ON2).
2) Verify that a shunt is across pins 1 and 3 of jumper
JU3 (PGM3).
3) Connect a voltmeter across the VI/O pad and IGND
pad to monitor the VI/O output voltage.
4) Connect a voltmeter across the VCORE pad and
CGND pad to monitor the VCORE output voltage.
5) Connect a voltmeter across the VMEM pad and
MGND pad to monitor the VMEM output voltage.
6) Connect the positive terminal of a 4.5V supply to the
VIN pad. Connect the negative terminal to the GND
pad.
Input Source
The MAX1702 EV kit has a 2.6V to 5.5V input voltage
range that allows the use of batteries or a regulated DC
power supply as the power source. However, the EV kit
requires a minimum of 3.6V at the input for the VI/O out-
put supply to regulate to 3.3V ±2%. If the input voltage
falls below 3.6V, VI/O tracks the input voltage. If VMEM
is configured to regulate at 3.3V, it also tracks the input
voltage below 3.6V.
Input Thresholds
The MAX1702B contains two low-battery detection
thresholds, dead battery (DBI) and low-battery (LBI),
that are used to monitor the input power source to the
EV kit. These thresholds are programmable with exter-
nal resistors. The DBI threshold is set to 2.7V and the
Component Suppliers
SUPPLIER
Sumida
Taiyo Yuden
TDK
PHONE
847-545-6700
800-348-2496
847-803-6100
FAX
847-545-6720
847-925-0899
847-390-4405
WEBSITE
www.sumida.com
www.t-yuden.com
www.component.tdk.com
Note:
Please indicate that you are using the MAX1702 when contacting these component suppliers.
2
_______________________________________________________________________________________
MAX1702 Evaluation Kit
Evaluates: MAX1702B
Table 1. VMEM Output Settings (JU2)
SHUNT STATUS
1 and 2
1 and 3
1 and 4
PIN CONNECTION
PGM3 connected to VIN
PGM3 connected to REF
PGM3 connected to GND
VMEM
OUTPUT (V)
3.3
2.5
1.8
2 and 3
ON2 connected
to GND
Table 2. Normal/Sleep Mode (JU1)
SHUNT STATUS
1 and 2
PIN
CONNECTION
ON2 connected
to VIN
EV KIT OPERATION
Normal mode
Sleep mode (VCORE
disabled, VI/O and
VMEM remain
enabled)
External controller
determines operation
mode
LBI threshold is set to 3.6V with resistors R1, R2, and
R3. If the input source falls below the LBI threshold, the
low-battery
LBO
output is pulled low. The EV kit enters
shutdown mode when the input source falls below the
DBI threshold. Replace resistors R1, R2, and R3 with
different values to reconfigure the DBI and LBI thresh-
olds. Refer to the MAX1702B data sheet to select new
resistor values for R1, R2, and R3.
None
ON2 connected
to external
controller
Power-Up Sequence
The MAX1702 EV kit power-up sequence is initiated
when the input voltage is greater than the dead-battery
setting (DBI) and greater than the UVLO threshold
(2.4V). During initial power-up, VI/O first ramps up in a
soft-start mode. Once VI/O reaches its regulation volt-
age, VMEM ramps to its target in soft-start mode.
Finally, once VMEM reaches its regulation voltage,
VCORE ramps to its target in soft-start mode. The reset
output
RSO
is held low during this time. Once the
VCORE output has reached its target voltage, a 65.5ms
reset timer is started.
RSO
is pulled high when the timer
expires. The timer may be manually reset by pushing
the momentary switch SW1 or by applying a logic-low
signal at the
MR
pad. The outputs stay on during the
manual reset.
data sheet for instructions on selecting resistors R5 and
R6. VMEM can supply 800mA at an output voltage of
3.3V, 2.5V, or 1.8V and can be set by configuring JU2.
See Table 1 for JU2 configuration. VI/O output voltage
is fixed to 3.3V and can supply 900mA.
SLEEP Mode
The EV kit contains a 3-pin jumper (JU1) that can be
used to enable the MAX1702B in normal mode or to
place it in sleep mode. In normal operation, the three
converters are enabled. In sleep mode, VCORE is in
shutdown while VI/O and VMEM remain enabled. Sleep
mode allows the microprocessor to enter sleep mode
while memory and I/O peripherals are kept alive in a
system application. See Table 2 for JU1 configuration.
Normal and sleep modes can also be controlled with
an external device by removing the shunt on JU1 and
applying a CMOS logic-level signal to the ON2 pad.
Triple Outputs
The MAX1702 EV kit features three (VCORE, VMEM,
and VI/O) step-down DC-DC converters that can be set
to regulate to different voltages. VCORE can supply
400mA at an output voltage of 1.1V. The VCORE output
voltage is set with resistors R5 and R6. Refer to the
Setting the Output Voltages
section in the MAX1702B
OUTOK Output
The MAX1702 EV kit provides an OUTOK logic output
signal to indicate the regulation state of VCORE. A logic
low at the OUTOK pad indicates that the VCORE output
has dropped to 92.5% of its regulation voltage. A logic
high at OUTOK indicates that VCORE is 95.5% of its
regulation voltage.
_______________________________________________________________________________________
3
MAX1702 Evaluation Kit
Evaluates: MAX1702B
VIN
VIN
C9
OPEN
GND
LBO
C1
4.7µF
R1
267kΩ
1%
R3
137kΩ
1%
1
3
R2
90.9kΩ
1%
2
36
9
18
19
10
INP1
DBI N.C. N.C. N.C. N.C. IN
15
C10
1µF
LBI
LBO
OUT1
LX1
N.C.
20
14
13
12
L1
4.7µH
C2
10µF
VI/O
VI/O
C11
OPEN
IGND
R4
33kΩ
VIN
C18
33pF
C12
1µF
C16
OPEN
R6
14kΩ
1%
VCORE
R13
1Ω
C17
10µF
VPLL
CGND
R7
18kΩ
C19
33pF
L3
4.7µH
C4
10µF
C6
680pF
VMEM
C15
OPEN
MGND
C5
1000pF
R9
100kΩ
R10
100kΩ
22
1
VIN
2 JU1
VI/O
VI/O
R11
100kΩ
11
R12
100kΩ
SW1
16
4
VI/O
OUTOK
ON2
U1
PG1
OUTOK
ON2
MAX1702B
COMP1
INP2
N.C.
17
25
26
27
28
R5
8.06kΩ
1%
L2
4.7µH
C3
10µF
3
RSO
MR
RSO
N.C.
FB2
MR
LX2
24
23
6
REF
7
REF
C8
0.1µF
VIN
2
REF
3
JU2 4
1
8
5
GND
PG2
REF
C13
OPEN
COMP2 21
29
OUT3
LX3
PG3
33
32
PGM3
GND
COMP3
30
VIN
C20
33pF
N.C. INP3 N.C. 31
35
34
C14
1µF
C7
1000pF
R8
22kΩ
Figure 1. MAX1702 EV Kit Schematic
4
_______________________________________________________________________________________
MAX1702 Evaluation Kit
Evaluates: MAX1702B
Figure 2. MAX1702 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX1702 EV Kit PC Board Layout—Component Side
Figure 4. MAX1702 EV Kit PC 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 ____________________
© 2002 Maxim Integrated Products
Printed USA
5
is a registered trademark of Maxim Integrated Products.
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