19-5966; Rev 0; 6/11
EVALUATION KIT AVAILABLE
MAX15112
High-Efficiency, 12A, Current-Mode Synchronous
Step-Down Regulator with Integrated Switches
General Description
The MAX15112 high-efficiency, current-mode step-down
regulator with integrated power switches operates from
2.7V to 5.5V and delivers up to 12A of output current in a
small 2mm x 3mm package. The MAX15112 offers excel-
lent efficiency with skip mode capability at light-load con-
ditions, yet provides unmatched efficiency under heavy
load conditions. The combination of small size and high
efficiency makes this device suitable for both portable
and nonportable applications.
The MAX15112 utilizes a current-mode control architecture
with a high-gain transconductance error amplifier, which
allows a simple compensation scheme and enables a
cycle-by-cycle current limit with fast response to line and
load transients. A factory-trimmed switching frequency of
1MHz (PWM operation) allows for a compact, all-ceramic
capacitor design.
Integrated switches with low on-resistance ensure high
efficiency at heavy loads while minimizing critical induc-
tances. The MAX15112’s simple layout and footprint
assure first-pass success in new designs.
Other features of the MAX15112 include a capacitor-
programmable soft-start to reduce inrush current, safe
startup into a prebiased output, an enable input, and a
power-good output for power sequencing.
The regulator is available in a 24-bump (4 x 6), 2.10mm
x 3.05mm WLP package, and is fully specified over the
-40NC to +85NC extended temperature range.
Features
S
Continuous12AOutputCurrentOverTemperature
S
±1%FeedbackAccuracyOverLoad,Line,and
Temperature
S
Operatesfrom2.7Vto5.5VSupply
S
InputUndervoltageLockout
S
AdjustableOutputRangefrom0.6VUpto0.94xV
IN
S
ProgrammableSoft-Start
S
Factory-Trimmed1MHzSwitchingFrequency
S
StablewithLow-ESRCeramicOutputCapacitors
S
Safe-StartupintoaPrebiasedOutput
S
ExternalReferenceInput
S
SelectableSkipModeOptionforImproved
EfficiencyatLightLoads
S
EnableInput/PGOODOutputAllowsSequencing
S
RemoteGroundSenseforImprovedAccuracy
S
ThermalandOvercurrentProtection
S
Tiny2.10mmx3.05mm,24-BumpWLPPackage
Applications
Notebooks
Servers
Distributed Power Systems
DDR Memory
Base Stations
Ordering Information
appears at end of data sheet.
Typical Operating Circuits
ON
OFF
EN
SKIP
AIN
V
IN
= 2.7V TO 5.5V
IN
C
IN
PGOOD
PGOOD
SS/REFIN
C
SS
PWM MODE OPERATION
GND
COMP
C
CC
R
C
C
C
R2
R
PULL
FB
LX
BST
C
BST
L
OUT
C
OUT
GSNS
R1
V
OUT
MAX15112
Typical Operating Circuits
continued at end of data sheet.
For related parts and recommended products to use with this part, refer to:
www.maxim-ic.com/MAX15112.related
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½ Maxim
Integrated Products
1
½
Forpricing,delivery,andorderinginformation,pleasecontactMaximDirectat1-888-629-4642,
orvisitMaxim’swebsiteatwww.maxim-ic.com.
MAX15112
High-Efficiency, 12A, Current-Mode Synchronous
Step-Down Regulator with Integrated Switches
ABSOLUTEMAXIMUMRATINGS
IN, PGOOD to GND ................................................-0.3V to +6V
EN, COMP, FB, SS/REFIN, GSNS, SKIP,
LX to GND ..............................................-0.3V to (V
IN
+ 0.3V)
LX to GND (for 10ns)........................................-2V to (V
IN
+ 2V)
LX to GND (for 50ns)........................................-1V to (V
IN
+ 1V)
BST to LX.................................................................-0.3V to +6V
BST to GND ...........................................................-0.3V to +12V
BST to IN .................................................................-0.3V to +6V
LX Continuous Current (Note 1) .........................................
Q15A
Output Short-Circuit Duration ...................................Continuous
Continuous Power Dissipation
WLP (derate 53.85mW/NC above +70NC)......................2.15W
Operating Temperature Range .......................... -40NC to +85NC
Junction Temperature (Note 2) .......................................+110NC
Storage Temperature Range............................ -65NC to +150NC
Bump Reflow Temperature (Note 3) ...............................+260NC
Note1:
LX has internal clamp diodes to GND and IN. Applications that forward bias these diodes must take care not to exceed
the IC’s package power dissipation limits.
Note2:
Limit the junction temperature to +110NC for continuous operation at maximum output current.
Note3:
The WLP package is constructed using a unique set of package techniques that impose a limit on the thermal profile the
device can be exposed to during board-level solder attach and rework. This limit permits only the use of the solder pro-
files recommended in the industry-standard specification JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and convection
reflow. Preheating is required. Hand or wave soldering is not allowed.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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.
DCELECTRICALCHARACTERISTICS
(V
IN
= 5V, see the
Typical Operating Circuits,
T
A
= -40NC to +85NC. Typical values are at T
A
= +25NC, unless otherwise noted.) (Note 4)
PARAMETER
IN Voltage Range
IN Supply Current
IN Shutdown Current
IN Undervoltage Lockout
Threshold
IN Undervoltage Lockout
Threshold Hysteresis
ERRORAMPLIFIER
Transconductance
Voltage Gain
FB Setpoint Voltage
FB Input Bias Current
COMP to Current-Sense
Transconductance
COMP Clamp Low Voltage
Slope Compensation Ramp
Amplitude
V
SLOPE
g
M
A
VEA
V
FB
I
FB
g
MC
V
FB
= 0.65V, V
SS/REFIN
= 0.6V
Over line, load, and temperature
V
FB
= 0.6V
0.594
-500
80
0.91
130
1.1
90
0.600
0.606
+500
mS
dB
V
nA
A/V
V
mV
SYMBOL
V
IN
I
IN
I
SHDN
V
UVLO
V
EN
= V
IN
, V
FB
= 0.5V, no switching
V
EN
= 0V
V
IN
rising, LX starts switching
V
IN
falling, LX stops switching
CONDITIONS
MIN
2.7
4.6
0.01
2.6
200
TYP
MAX
5.5
7
3
2.68
UNITS
V
mA
FA
V
mV
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½ Maxim
Integrated Products
2
½
MAX15112
High-Efficiency, 12A, Current-Mode Synchronous
Step-Down Regulator with Integrated Switches
DCELECTRICALCHARACTERISTICS(continued)
(V
IN
= 5V, see the
Typical Operating Circuits,
T
A
= -40NC to +85NC. Typical values are at T
A
= +25NC, unless otherwise noted.) (Note 4)
PARAMETER
GROUNDSENSE
GSNS Output Current
POWERSWITCHES
High-side switch
Current-Limit Threshold
LX Leakage Current
BST Leakage Current
BST On-Resistance
LX RMS Output Current
OSCILLATOR
Switching Frequency
Maximum Duty Cycle
Minimum Controllable On-Time
ENABLEFUNCTIONALITY
EN Input High Threshold
EN Input Low Threshold
EN Input Leakage Current
SKIPFUNCTIONALITY(Note5)
SKIP Input High Threshold
SKIP Input Low Threshold
SKIP Pulldown Resistor
Minimum LX On-Current in Skip
Mode
Zero-Crossing LX Threshold
SOFT-STARTANDPREBIASFUNCTIONALITY
Soft-Start Current
SS/REFIN Discharge Resistance
SS/REFIN Prebias Mode Stop
Voltage
SS/REFIN External Reference
Input Range
HICCUPMODE
Number of Consecutive Current-
Limit Events to Hiccup Mode
Hiccup Mode Timeout
N
HIC
8
1024
Events
Clock
Cycles
I
SS
R
SS
V
SS/REFIN
= 0.45V, sourcing
I
SS/REFIN
= 10mA, sinking
V
SS/REFIN
rising
6.8
10
7
0.58
V
IN
-
2.5
12.5
FA
I
V
V
V
SKIP
rising
V
SKIP
falling
0.4
230
3
0.5
1.4
V
V
kI
A
A
V
IH
V
IL
V
EN
rising
V
EN
falling
0.4
-1
+1
1.4
V
V
FA
f
SW
D
MAX
t
ON
PWM mode
Skip mode
850
1000
94
85
70
1150
kHz
%
ns
R
ON_BST
Low-side switch, sinking
Low-side switch, sourcing
V
EN
= 0V
V
EN
= 0V
I
BST
= 50mA
12
0.63
24
24
24
3
3
FA
FA
I
A
A
V
SS/REFIN
= 0.6V, V
GSNS
= 0V
52
FA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½ Maxim
Integrated Products
3
½
MAX15112
High-Efficiency, 12A, Current-Mode Synchronous
Step-Down Regulator with Integrated Switches
DCELECTRICALCHARACTERISTICS(continued)
(V
IN
= 5V, see the
Typical Operating Circuits,
T
A
= -40NC to +85NC. Typical values are at T
A
= +25NC, unless otherwise noted.) (Note 4)
PARAMETER
POWER-GOODOUTPUT
PGOOD Threshold
PGOOD Threshold Hysteresis
PGOOD Output Voltage Low
PGOOD Leakage Current
THERMALSHUTDOWN
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
T
SHDN
Die temperature rising
+150
20
NC
NC
V
PG_OL
I
PG_LK
V
FB
falling, PGOOD deasserts
V
FB
rising
I
PGOOD
= 5mA, V
EN
= 0V
V
PGOOD
= 5.5V, V
FB
= 0.65V
0.514
0.529
25
18
50
1
0.542
V
mV
mV
FA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note4:
All devices are 100% production tested at T
A
= +25NC. Limits over the operating temperature range are guaranteed by design.
Note5:
Connect SKIP to EN for skip mode functionality. Leave SKIP unconnected or connect to GND for PWM mode functionality.
Typical Operating Characteristics
(V
IN
= 5V, V
OUT
= 1.5V, I
LOAD
= 4A, C
SS
= 33nF, see the
Typical Operating Circuits,
T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 3.3V, PWM MODE)
MAX15112 toc01
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 5V, PWM MODE)
MAX15112 toc02
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 3.3V, SKIP MODE)
95
90
EFFICIENCY (%)
85
80
75
70
65
60
55
50
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 1.5V
V
OUT
= 2.5V
MAX15112 toc03
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.1
1
10
LOAD CURRENT (A)
V
OUT
= 1.2V
V
OUT
= 2.5V
V
OUT
= 1.8V
V
OUT
= 1.5V
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.1
1
10
V
OUT
= 3.3V
V
OUT
= 2.5V
V
OUT
= 1.8V
V
OUT
= 1.2V
V
OUT
= 1.5V
100
100
0.1
1
10
100
LOAD CURRENT (A)
LOAD CURRENT (A)
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½ Maxim
Integrated Products
4
½
MAX15112
High-Efficiency, 12A, Current-Mode Synchronous
Step-Down Regulator with Integrated Switches
Typical Operating Characteristics (continued)
(V
IN
= 5V, V
OUT
= 1.5V, I
LOAD
= 4A, C
SS
= 33nF, see the
Typical Operating Circuits,
T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
(V
IN
= 5V, SKIP MODE)
95
90
EFFICIENCY (%)
85
80
75
70
65
60
55
50
0.1
1
10
100
LOAD CURRENT (A)
V
OUT
= 1.8V
V
OUT
= 1.5V
V
OUT
= 2.5V
V
OUT
= 3.3V
MAX15112 toc04
SWITCHING FREQUENCY
vs. INPUT VOLTAGE (PWM, I
OUT
= 0A)
1080
SWITCHNG FREQUENCY (kHz)
1060
1040
1020
1000
980
960
940
920
900
2.5
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
T
A
= -40°C
T
A
= +25°C
T
A
= +85°C
MAX15112 toc05
100
1100
OUTPUT VOLTAGE
vs. INPUT VOLTAGE (PWM)
MAX15112 toc06
OUTPUT VOLTAGE ERROR
vs. INPUT VOLTAGE (PWM, I
OUT
= 6A)
0.15
OUTPUT VOLTAGE ERROR (%)
0.10
0.05
0
-0.05
-0.10
-0.15
-0.20
V
OUT
= 1.8V
V
OUT
= 1.2V
REFERENCED TO V
IN
= 4V
MAX15112 toc07
1.508
1.506
OUTPUT VOLTAGE (V)
1.504
1.502
1.500
1.498
1.496
1.494
1.492
2.5
3.0
3.5
4.0
4.5
5.0
I
OUT
= 12A
I
OUT
= 0A
I
OUT
= 6A
0.20
5.5
2.5
3.0
3.5
4.0
4.5
5.0
5.5
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
OUTPUT VOLTAGE
vs. LOAD CURRENT (PWM, V
OUT
= 1.5V)
1.508
1.506
OUTPUT VOLTAGE (V)
1.504
1.502
1.500
1.498
1.496
1.494
1.492
1.490
0
2
4
6
8
10
12
LOAD CURRENT (A)
V
IN
= 5V
V
IN
= 3.3V
MAX15112 toc08
1.510
LOAD-TRANSIENT RESPONSE
(V
IN
= 5V, PWM, 1A /µs)
MAX15112 toc09
V
OUT
20mV/div
AC-COUPLED
6A
I
OUT
2A/div
0.1A
40µs/div
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½ Maxim
Integrated Products
5
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
