19-0510; Rev 1; 6/08
MAX8566 Evaluation Kit
General Description
The MAX8566 evaluation kit (EV kit) demonstrates the
MAX8566 integrated 10A step-down converter. The EV
kit generates a 1.8V output voltage at load currents up
to 10A from a 2.3V to 3.6V input voltage range. The
MAX8566 switches at 1MHz and provides over 95%
efficiency with the supplied components.
The MAX8566 EV kit comes fully assembled and tested
Features
Ω
o
Internal 8mΩ On-Resistance MOSFETs
o
10A Output PWM Step-Down Regulator
o
±1% Output Accuracy Over Load, Line, and
Temperature
o
Operates from 2.3V to 3.6V Input Supply
o
Adjustable Output from 0.6V to (0.87 x V
IN
)
o
250kHz to 2.4MHz Adjustable Frequency or SYNC
Input
o
Allows All Ceramic Capacitor Design
o
SYNCOUT Drives 2nd Regulator 180° Out-of-Phase
o
Prebiased or Monotonic Soft-Start
o
o
o
o
o
o
Programmable Soft-Start Time
Output Tracking or Sequencing
32-Lead, 5mm x 5mm Thin QFN Package
REFIN for DDR Termination Applications
Surface-Mount Components
Assembled and Tested
Evaluates: MAX8566
Ordering Information
PART
MAX8566EVKIT
TYPE
EV Kit
Component List
DESIGNATION
QTY
DESCRIPTION
47µF ±20%, 6.3V X7R ceramic
capacitors (1210)
Taiyo Yuden JMK325BJ476MM
or equivalent
0.22µF ±10%, 10V X7R ceramic
capacitor (0603)
TDK C1608X7R1A224K
or equivalent
4.7µF ±20%, 6.3V X5R ceramic
capacitor (0603)
TDK C1608X5R0J475K
or equivalent
0.047µF, 25V X7R ceramic capacitor
(0603)
TDK C1608X7R1E473K
or equivalent
22µF ±20%, 6.3V X5R ceramic
capacitors (1206)
TDK C3216X5R0J226M
or equivalent
2200pF ±10%, 50V X7R ceramic
capacitors (0402)
TDK C1005X7R1H222K
or equivalent
DESIGNATION
QTY
DESCRIPTION
120pF ±5%, 50V C0G ceramic
capacitor (0402)
Murata GRM36C0G121J50D50
or equivalent
0.022µF ±10%, 16V X7R ceramic
capacitor (0402)
TDK C1005X7R1C223K
or equivalent
Not installed, ceramic capacitor
3300pF ±10%, 50V X7R ceramic
capacitor (0402)
TDK C1005X7R1H332K
or equivalent
0.1µF ±10%, 50V X7R ceramic
capacitor (0805)
Taiyo Yuden UMK212BJ104KG
or equivalent
2-pin header
36-pin header, 0.01in center
(comes in 36-pin strips, cut to fit)
Sullins PTC36SAAN
0.39µH, 2.51mΩ, 16.3A inductor
7.6mm x 6.8mm x 5mm
TOKO FDU0650-0R39
C1, C2
2
C10
1
C3
1
C11
1
C12
0
C4
1
C13
1
C5
1
C14
1
C6, C7
2
JU1
1
C8, C9
2
L1
1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX8566 Evaluation Kit
Evaluates: MAX8566
Component List (continued)
DESIGNATION
R1
R2
R3
R4
R5
R6
R7
R8
R9, R10
QTY
1
1
1
1
1
1
1
1
0
DESCRIPTION
10Ω ±5% resistor (0402)
20kΩ ±5% resistor (0402)
49.9kΩ ±1% resistor (0402)
100Ω ±5% resistor (0402)
4.02kΩ ±1% resistor (0402)
2.00kΩ ±1% resistor (0402)
2.49kΩ ±1% resistor (0402)
2.4Ω ±5% resistor (0603)
Not installed, resistors (0402)
—
1
—
1
DESIGNATION
R11
R12
U1
QTY
1
1
1
DESCRIPTION
10kΩ ±5% resistor (0402)
100kΩ ±5% resistor (0402)
10A step-down converter (32 TQFN)
Maxim MAX8566ETJ+
Shunt
Sullins STC02SYAN
Digi-Key S9000-ND
PCB: MAX8566 Evaluation Kit
Component Suppliers
SUPPLIER
Digi-Key Corp.
Murata Electronics North America, Inc.
Sullins Electronics Corp.
Taiyo Yuden
TDK Corp.
TOKO America, Inc.
PHONE
800-344-4539
770-436-1300
760-744-0125
800-348-2496
847-803-6100
847-297-0070
www.digikey.com
www.murata-northamerica.com
www.sullinselectronics.com
www.t-yuden.com
www.component.tdk.com
www.tokoam.com
WEBSITE
Note:
Indicate you are using the MAX8566 when contacting these component suppliers.
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
• 2V to 4V at +10A variable DC power supply or battery
•
•
•
Digital multimeter (DMM)
10A load
Ammeter (optional)
4) Connect the positive lead of the DMM to the VOUT
pad on the EV kit and connect the negative lead of
the DMM to the GND pad on the EV kit.
5) Turn on the power supply.
6) Verify that the voltage at VOUT is approximately 1.8V.
7) Connect a 10A load between VOUT and GND.
8) Verify that the voltage at VOUT is approximately 1.8V.
9) If performing transient response testing, it is recom-
mended to add at least 270µF electrolitic capaci-
tance to the input between the GND and VIN pads of
the EV kit to prevent overshoot.
Procedure
The MAX8566 application circuit is fully assembled and
tested. Follow the steps below to verify board opera-
tion:
1) Preset the DC power supply to 3.3V. Turn off the
power supply.
Do not turn on the power supply
until all connections are made.
2) Remove the shunt from JU1.
3) Connect the positive lead of the power supply to the
VIN pad on the EV kit and connect the negative lead
of the power supply to the GND pad on the EV kit.
Detailed Description of Hardware
Evaluating Other Output Voltages
The MAX8566 EV kit comes preset to a 1.8V output volt-
age. The output of the MAX8566 is adjustable down to
0.6V. To adjust the output voltage, replace R6 with a
1% resistor with a value corresponding to the equation:
R6
=
4.02kΩ
⎛
V
OUT
⎞
−
1
⎟
⎜
⎝
0.6V
⎠
2
_______________________________________________________________________________________
MAX8566 Evaluation Kit
Note that V
OUT
cannot exceed V
IN
and is limited by the
maximum duty cycle of the MAX8566.
Refer to the MAX8566 IC data sheet for information on
selecting inductor, output capacitor, and compensation
components to optimize the circuit for different output volt-
ages.
using an external reference. A method of soft-start
when using an external reference is shown in Figure 2
of the MAX8566 IC data sheet. To use the REFIN input
of the EV kit, cut the trace that shorts R9. Connect a
power supply to the REFIN pad on the EV kit.
Evaluates: MAX8566
Power Good (PWRGD)
PWRGD is an open-drain output that goes high imped-
ance once the soft-start ramp has concluded, provided
V
FB
is above 0.54V. PWRGD pulls low when V
FB
is
below 0.54V for at least 50µs. PWRGD is low during
shutdown. PWRGD is pulled up to V
DD
through R2.
Evaluating Other Switching
Frequencies (FREQ)
The MAX8566 EV kit comes preset with a 1MHz switch-
ing frequency. Replace R3 to change the switching fre-
quency. R3 is calculated as:
⎛
1
⎞
50k
Ω
R3
=
× ⎜ −
0.05
μ
s
⎟
0.95
μ
s
⎝
f
S
⎠
where the switching frequency (f
S
) is in Hz and must be
between 250kHz and 2.4MHz.
Refer to the MAX8566 IC data sheet for information on
selecting inductor, output capacitor, and compensation
components to optimize the circuit for different switching
frequencies.
SYNC and SYNCOUT
The MAX8566 provides a SYNC input that allows the IC
to be synchronized to an external clock frequency of
250kHz to 2.4MHz. The clock frequency of the signal
applied to SYNC must be faster than the internal oscil-
lator. The SYNCOUT output is provided to operate a
second regulator 180° out-of-phase.
Jumper Settings
Jumper JU1 Function (Shutdown Mode)
The MAX8566 features a shutdown mode to minimize
the quiescent current. To shut down the IC, place a
shunt between pins 1-2 of JU1. For normal operation,
remove the shunt from JU1.
Using the REFIN Input
The MAX8566 features an external reference input
(REFIN). The IC regulates FB to the voltage applied to
REFIN. The internal soft-start is not available when
_______________________________________________________________________________________
3
MAX8566 Evaluation Kit
Evaluates: MAX8566
VIN
2.3V TO 3.6V
18
IN
BST
4
C5
0.047μF
L1
0.39μH
C2
47μF
C14
0.1μF
19
IN
20
IN
21
IN
22
IN
U1
LX
LX
LX
LX
LX
LX
24
C4
4.7μF
V
DD
LX
LX
PGND
PGND
PGND
5
6
7
8
9
10
11
12
17
16
15
14
13
GND
R7
2.49kΩ
1%
C10
120pF
3
PWRGD
SYNCOUT
30
SYNCOUT
C9
2200pF
R6
2kΩ
1%
C13
3300pF
R5
4.02kΩ
1%
R8
2.4Ω
C6
22μF
C7
22μF
R4
100Ω
GND
C1
47μF
VOUT
1.8V AT 10A
MAX8566
23
C3
0.22μF
LSS
R1
10Ω
C8
2200pF
R12
100kΩ
EN
JU1
R10
OPEN
27
EN
PGND
PGND
1
R11
10kΩ
MODE
FB
32
R2
20kΩ
PWRGD
COMP
2
REFIN
C12
OPEN
R9
PC BOARD
SHORT
R3
49.9kΩ
1%
25
REFIN
SYNC
SS
FREQ
GND
31
C11
0.022μF
28
26
SYNC
29
Figure 1. MAX8566 EV Kit Schematic
4
_______________________________________________________________________________________
MAX8566 Evaluation Kit
Evaluates: MAX8566
Figure 2. MAX8566 EV Kit Component Placement Guide—Top
Silkscreen
Figure 3. MAX8566 EV Kit PCB Layout—Component Side
Figure 4. MAX8566 EV Kit PCB Layout—Layer 2
Figure 5. MAX8566 EV Kit PCB Layout—Layer 3
_______________________________________________________________________________________
5
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