19-5478; Rev 2; 7/11
High-Efficiency, 3A, Current-Mode
Synchronous, Step-Down Switching Regulator
General Description
The MAX15058 high-efficiency, current-mode, synchro-
nous step-down switching regulator with integrated
power switches delivers up to 3A of output current.
The device operates from 2.7V to 5.5V and provides an
output voltage from 0.6V up to 94% of the input voltage,
making the device ideal for distributed power systems,
portable devices, and preregulation applications.
The MAX15058 utilizes a current-mode control archi-
tecture with a high-gain transconductance error ampli-
fier. The current-mode control architecture facilitates
easy compensation design and ensures cycle-by-cycle
current limit with fast response to line and load transients.
The MAX15058 offers selectable skip-mode functional-
ity to reduce current consumption and achieve a higher
efficiency at light output load. The low R
DS(ON)
inte-
grated switches ensure high efficiency at heavy loads
while minimizing critical inductances, making the layout
design a much simpler task with respect to discrete
solutions. Utilizing a simple layout and footprint assures
first-pass success in new designs.
The MAX15058 features a 1MHz, factory-trimmed, fixed-
frequency PWM mode operation. The high switching fre-
quency, along with the PWM current-mode architecture,
allows for a compact, all-ceramic capacitor design.
The MAX15058 offers a capacitor-programmable soft-
start reducing inrush current, startup into PREBIAS
operations, and a PGOOD open-drain output that can be
used as an interrupt and for power sequencing.
The MAX15058 is available in a 9-bump (3 x 3 array),
1.5mm x 1.5mm WLP package and is specified over the
-40NC to +85NC temperature range.
(typ) Low-Side MOSFETs at 5V
TION KIT
EVALUA BLE
AVAILA
Features
S
Internal 30mI (typ) R
DS(ON)
High-Side and 18mI
S
Continuous 3A Output Current Over Temperature
S
95% Efficiency with 3.3V Output at 3A
S
1% Output Voltage Accuracy Over Load, Line, and
MAX15058
Temperature
S
Operates from 2.7V to 5.5V Supply
S
Cycle-by-Cycle Overcurrent Protection
S
Adjustable Output from 0.6V to Up to 0.94 x V
IN
S
Programmable Soft-Start
S
Factory-Trimmed, 1MHz Switching Frequency
S
Stable with Low-ESR Ceramic Output Capacitors
S
Safe-Startup Into Prebiased Output
S
External Reference Input
S
Skip-Mode Functionality
S
Enable Input/Power-Good Output
S
Fully Protected Against Overcurrent and
Overtemperature
S
Input Undervoltage Lockout
Ordering Information
PART
MAX15058EWL+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
9 WLP
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Applications
Distributed Power Systems
Preregulators for Linear Regulators
Portable Devices
Notebook Power
Server Power
IP Phones
ENABLE
OFF
ON
INPUT
2.8V TO 5.5V
Typical Operating Circuit
OUTPUT
1.8V/3A
IN
LX
MAX15058
GND
PGOOD
FB
EN
SKIP
SS/REFIN
COMP
_______________________________________________________________
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.
High-Efficiency, 3A, Current-Mode
Synchronous, Step-Down Switching Regulator
MAX15058
ABSOLUTE MAXIMUM RATINGS
IN, PGOOD to GND ................................................-0.3V to +6V
LX to GND ..................................................-0.3V to (V
IN
+ 0.3V)
LX to GND .......................................-1V to (V
IN
+ 0.3V) for 50ns
EN, COMP, FB, SS/REFIN, SKIP to GND ...-0.3V to (V
IN
+ 0.3V)
LX Current (Note 1) ................................................... -6A to +6A
Output Short-Circuit Duration ....................................Continuous
Continuous Power Dissipation (T
A
= +70NC)
9-Bump WLP Multilayer Board
(derate 14.1mW/NC above T
A
= +70NC) ....................1127mW
Operating Temperature Range .......................... -40NC to +85NC
Storage Temperature Range............................ -65NC to +150NC
Soldering Temperature (reflow) ......................................+260NC
Note 1:
LX has internal clamp diodes to GND and IN. Applications that forward bias these diodes should not exceed the IC’s pack-
age power dissipation limits.
PACKAGE THERMAL CHARACTERISTICS (Note 2)
WLP
Junction-to-Case Thermal Resistance (B
JC
) ...................26NC/W
Junction-to-Ambient Thermal Resistance (B
JA
) ..............71NC/W
Note 2:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
IN
= 5V, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are at T
A
= +25NC.) (Note 3)
PARAMETER
IN Voltage Range
IN Shutdown Supply Current
IN Supply Current
V
IN
Undervoltage Lockout
Threshold
V
IN
Undervoltage Lockout
Hysteresis
ERROR AMPLIFIER
Transconductance
Voltage Gain
FB Set-Point Accuracy
FB Input Bias Current
COMP to Current-Sense
Transconductance
COMP Clamp Low
POWER SWITCHES
LX On-Resistance, High-Side
pMOS
LX On-Resistance, Low-Side
nMOS
High-Side Switch Current-Limit
Threshold
Low-Side Switch Sink Current-
Limit Threshold
Low-Side Switch Source Current-
Limit Threshold
2
I
HSCL
30
18
5
4
5
mI
mI
A
A
A
g
MV
A
VEA
V
FB
I
FB
g
MC
V
FB
= 0.65V, V
SS
= 0.6V
Over line, load, and temperature
V
FB
= 0.6V
594
-500
18
0.94
1.5
90
600
606
+500
mS
dB
mV
nA
A/V
V
I
IN
SYMBOL
V
IN
V
EN
= 0V
V
EN
= 5V, V
FB
= 0.65V, no switching
LX starts switching, V
IN
rising
LX stops switching, V
IN
falling
CONDITIONS
MIN
2.7
0.2
1.56
2.6
200
TYP
MAX
5.5
2
2.3
2.7
UNITS
V
FA
mA
V
mV
______________________________________________________________________________________
High-Efficiency, 3A, Current-Mode
Synchronous, Step-Down Switching Regulator
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 5V, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are at T
A
= +25NC.) (Note 3)
PARAMETER
LX Leakage Current
RMS LX Output current
OSCILLATOR
Switching Frequency
Maximum Duty Cycle
Minimum Controllable On-Time
Slope Compensation Ramp
Valley
Slope Compensation Ramp
Amplitude
ENABLE
EN Input High Threshold Voltage
EN Input Low Threshold Voltage
EN Input Leakage Current
SKIP Input Leakage Current
SOFT-START, PREBIAS, REFIN
Soft-Start Current
SS/REFIN Discharge Resistance
SS/REFIN Prebias Mode Stop
Voltage
External Reference Input Range
HICCUP
Number of Consecutive Current-
Limit Events to Hiccup
Timeout
POWER-GOOD OUTPUT
PGOOD Threshold
PGOOD Threshold Hysteresis
PGOOD V
OL
PGOOD Leakage
THERMAL SHUTDOWN
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
Temperature falling
150
20
NC
NC
V
FB
rising
V
FB
falling
I
PGOOD
= 5mA, V
FB
= 0.5V
V
PGOOD
= 5V, V
FB
= 0.65V
0.535
8
1024
0.555
28
20
0.013
60
0.575
Events
Clock
Cycles
V
mV
mV
FA
I
SS
R
SS
V
SS/REFIN
= 0.45V, sourcing
I
SS/REFIN
= 10mA, sinking
V
SS/REFIN
rising
0
10
8.3
0.58
IN - 1.8
FA
I
V
V
V
EN
rising
V
EN
falling
V
EN
= 5V
V
SKIP
= V
EN
= 5V
1.45
0.4
0.025
25
V
V
FA
FA
V
SLOPE
Extrapolated to 100% duty cycle
f
SW
D
MAX
850
1000
94
70
1.15
320
1150
kHz
%
ns
V
mV
SYMBOL
V
EN
= 0V
3
CONDITIONS
MIN
TYP
MAX
10
UNITS
FA
A
MAX15058
3
Note 3:
Specifications are 100% production tested at T
A
= +25NC. Limits over the operating temperature range are guaranteed by
design and characterization.
_______________________________________________________________________________________
High-Efficiency, 3A, Current-Mode
Synchronous, Step-Down Switching Regulator
MAX15058
Typical Operating Characteristics
(V
IN
= 5V, V
OUT
= 1.8V, I
LOAD
= 3A, Circuit of Figure 5, T
A
= +25NC, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
(PWM MODE)
MAX15058 toc01
EFFICIENCY vs. OUTPUT CURRENT
(FORCED PWM)
MAX15058 toc02
EFFICIENCY vs. LOAD CURRENT
(SKIP MODE)
MAX15058 toc03
100
95
EFFICIENCY (%)
90
85
80
V
OUT
= 3.3V
V
OUT
= 2.5V
100
100
95
EFFICIENCY (%)
90
V
OUT
= 2.5V
95
EFFICIENCY (%)
90
85
80
V
OUT
= 1.8V
V
OUT
= 1.5V
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 1.5V
85
80
75
V
OUT
= 1.5V
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 2.5V
V
OUT
= 3.3V
V
OUT
= 1.2V
V
IN
= 5V
75
0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT CURRENT (A)
75
0
0.5
1.0
1.5
2.0
V
IN
= 3.3V
2.5
3.0
70
0
0.5
1.0
1.5
2.0
V
IN
= 5V
2.5
3.0
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
EFFICIENCY vs. OUTPUT CURRENT
(SKIP MODE)
V
OUT
= 2.5V
95
EFFICIENCY (%)
90
85
80
MAX15058 toc04
SWITCHING FREQUENCY
vs. INPUT VOLTAGE
1080
SWITCHING FREQUENCY (kHz)
1060
1040
1020
1000
980
960
940
920
900
3.0
2.7
3.2
3.7
4.2
4.7
5.2
INPUT VOLTAGE (V)
MAX15058 toc05
100
1100
V
OUT
= 1.8V
V
OUT
= 1.5V
V
OUT
= 1.2V
V
IN
= 3.3V
75
0
0.5
1.0
1.5
2.0
2.5
OUTPUT CURRENT (A)
OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX15058 toc06
OUTPUT VOLTAGE
vs. OUTPUT CURRENT
1.89
1.87
OUTPUT VOLTAGE (V)
1.85
1.83
1.81
1.79
1.77
MAX15058 toc07
1.89
1.87
OUTPUT VOLTAGE (V)
1.85
1.83
1.81
1.79
1.77
1.75
2.7
V
OUT
= 3.3V
V
OUT
= 5V
I
OUT
= 0.5A
3.2
3.7
4.2
4.7
5.2
1.75
0
0.5
1.0
1.5
2.0
2.5
3.0
SUPPLY VOLTAGE (V)
OUTPUT CURRENT (A)
4
______________________________________________________________________________________
High-Efficiency, 3A, Current-Mode
Synchronous, Step-Down Switching Regulator
Typical Operating Characteristics (continued)
(V
IN
= 5V, V
OUT
= 1.8V, I
LOAD
= 3A, Circuit of Figure 5, T
A
= +25NC, unless otherwise noted.)
MAX15058
LOAD-TRANSIENT RESPONSE
MAX15058 toc08
SWITCHING WAVEFORMS (I
OUT
= 3A)
MAX15058 toc09a
50mV/div
AC-COUPLED
V
OUT
20mV/div
AC-COUPLED
I
LX
1AV/div
1A/div
0A
V
LX
5V/div
100µs/div
400ns/div
SWITCHING WAVEFORMS (I
OUT
= 3A)
MAX15058 toc09b
SWITCHING WAVEFORM IN SKIP MODE
(I
OUT
= 10mA)
MAX15058 toc10
V
OUT
20mV/div
AC-COUPLED
I
LX
1AV/div
V
OUT
50mV/div
AC-COUPLED
I
LX
1A/div
0A
V
IN
= 3.3V
400ns/div
10µs/div
V
LX
5V/div
V
LX
5V/div
INPUT AND OUTPUT
WAVEFORMS (I
OUT
= 3A)
MAX15058 toc11
SHUTDOWN WAVEFORM
MAX15058 toc12
V
ENABLE
5V/div
INPUT
20mV/div
AC-COUPLED
OUTPUT
100mV/div
AC-COUPLED
V
OUT
1V/div
I
LX
1A/div
V
PGOOD
5V/div
400ns/div
10µs/div
_______________________________________________________________________________________
5
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