19-3690; Rev 1; 2/09
KIT
ATION
EVALU
BLE
AVAILA
High-Efficiency, 10A, PWM
Internal-Switch Step-Down Regulator
General Description
Features
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
Programmable Soft-Start Time
o
Output Tracking or Sequencing
o
Sourcing and Sinking Output Current
o
Power-Good Output
o
32-Lead Thin QFN Package
o
REFIN for DDR-Termination Application
MAX8566
The MAX8566 high-efficiency switching regulator deliv-
ers up to 10A load current at output voltages from 0.6V
to (0.87 x V
IN
). The IC operates from 2.3V to 3.6V input
supplies, making it ideal for point-of-load applications.
The total output-voltage set error is less than ±1% over
load, line, and temperature.
The MAX8566 operates in pulse-width-modulation
(PWM) mode with a 250kHz to 2.4MHz switching fre-
quency range that is programmable by an external
resistor. The IC can be synchronized to an external
clock in the same frequency range using the SYNC
input. The high operating frequency minimizes the size
of external components. Using low-R
DS(ON)
n-channel
MOSFETs for both high- and low-side switches main-
tains high efficiency at both heavy-load and high-
switching frequencies.
The MAX8566 employs a voltage-mode control archi-
tecture with a high-bandwidth (> 10MHz) error amplifi-
er. The voltage-mode control architecture makes
switching frequencies greater than 1MHz possible,
achieving all-ceramic-capacitor designs to minimize PC
board space. The error amplifier works with Type 3
compensation to fully utilize the bandwidth of the high-
frequency switching to obtain fast transient response.
Adjustable soft-start time provides flexibility to minimize
input startup inrush current. An open-drain, power-
good (PWRGD) signal goes high when the output
reaches 90% of its regulation point.
The MAX8566 provides a SYNCOUT output to synchro-
nize a second MAX8566 or a second regulator switch-
ing 180° out-of-phase with the first to reduce the input
ripple current, which consequently reduces the input-
capacitance requirements. The MAX8566 also pro-
vides an external reference input (REFIN) for
output-tracking applications.
The MAX8566 is available in a 32-pin, 5mm x 5mm thin
QFN package. The MAX8566 and all the required exter-
nal components fit into a footprint of less than 0.80in
2
.
Ordering Information
PART
MAX8566ETJ+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
32 Thin QFN-EP*
+Denotes
lead(Pb)/RoHS-compliant free package.
*EP
= Exposed Pad.
Typical Operating Circuit
INPUT
2.25V TO 3.6V
V
DD
LSS
IN
IN
IN
IN
IN
REFIN FOR
TRACKING
REFIN
SS
SYSTEM
ENABLE
SYNC INPUT
PROGRAMMABLE
FREQUENCY
SYNC OUTPUT 180°
EN
SYNC
FREQ
SYNCOUT
GND
MAX8566ETJ+
STEP-DOWN REGULATOR
TQFN 5mm x 5mm
PGND
PGND
PGND
PGND
PGND
LX
LX
LX
L1
330nH/10A
OUTPUT
UP TO 10A
C5
2 x 22µF
6.3V
Applications
ASIC/CPU/DSP Core Voltages
POL Power Supplies
DDR Power Supplies
Base-Station Power Supplies
Fiber Power Supplies
Telecom Power Supplies
Network Power Supplies
MONOTONIC SS
SELECTION
POWER-GOOD
OUTPUT
COMP
MODE
FB
PWRGD
LX
BST
LX
LX
LX
COMPENSATION
Pin Configuration appears at end of data sheet.
________________________________________________________________
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.
LX
High-Efficiency, 10A, PWM
Internal-Switch Step-Down Regulator
MAX8566
ABSOLUTE MAXIMUM RATINGS
EN/SS, EN, IN, SYNC, SKIP, V
DD
,
LSS, PWRGD to GND ..........-0.3V to +4V (4.5V nonswitching)
SYNCOUT, SS, COMP, FB, REFIN,
FREQ to GND .........................................-0.3V to (V
DD
+ 0.3V)
LX Current (Note 1) .................................................-12A to +12A
BST to LX .................................-0.3V to +4V (4.5V nonswitching)
PGND to GND .......................................................-0.3V to +0.3V
Continuous Power Dissipation (T
A
= +85°C)
32-Pin Thin QFN (derate 33.3mW/°C above +70°C) .....2666.7W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
LX has internal clamp diodes to PGND and IN. Applications that forward bias these diodes should take care not to exceed
the IC’s package power-dissipation limits.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
IN
= V
DD
= V
EN
= 3.3V, V
FB
= 0.5V, V
SYNC
= 0V,
T
A
= 0°C to +85°C,
typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER
IN/V
DD
IN and V
DD
Voltage Range
LSS Voltage Range
IN Supply Current
V
DD
Supply Current
Total Shutdown Current into IN
and V
DD
V
DD
Undervoltage-Lockout
Threshold
BST
Shutdown Supply Current
PWM COMPARATOR
Comparator Propagation Delay
COMP
Clamp Voltage, High
Slew Rate
Shutdown Resistance
ERROR AMPLIFIER
FB Regulation Voltage
Error-Amplifier Common-Mode
Input Range
V
COMP
= 1V to 2V, V
DD
= 2.5V and 3.3V
V
DD
= 2.3V to 2.6V
V
DD
= 2.6V to 3.6V
Error-Amplifier Maximum Output
Current
0.594
0
0
0.8
0.6
0.606
V
DD
-
1.65
V
V
DD
-
1.7
mA
V
From COMP to GND, V
EN
= 0V
V
IN
= 2.3V to 3.6V, V
FB
= 0.7V
1.80
0.75
2.0
1.4
30
100
2.15
V
V/µs
Ω
10mV overdrive
20
ns
V
IN
= V
DD
= V
BST
= 3.6V, V
LX
=
3.6V or 0V, V
EN
= 0V
T
A
= +25°C
T
A
= 0°C to +85°C
0.05
10
µA
Quiescent current, V
FB
= 0.7V
f
S
= 1MHz, no load
Quiescent current, V
FB
= 0.7V
f
S
= 1MHz, V
LSS
= V
DD
V
IN
= V
DD
= V
LSS
= (V
BST
- V
LX
) = T
A
= +25°C
3.6V, V
EN
= 0V
T
A
= 0°C to +85°C
LX starts/stops switching, 2µs
deglitch
V
DD
rising
V
DD
falling
1.72
2.3
2.3
0.7
14
1.8
16
50
3
2.0
1.90
2.2
4
3.6
3.6
2.2
V
V
mA
mA
µA
V
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
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