19-2514; Rev 3; 8/04
Dual-Phase, Parallelable, Average Current-Mode
Controllers
General Description
The MAX5038/MAX5041 dual-phase, PWM controllers
provide high-output-current capability in a compact
package with a minimum number of external compo-
nents. The MAX5038/MAX5041 utilize a dual-phase,
average current-mode control that enables optimal use
of low R
DS(ON)
MOSFETs, eliminating the need for exter-
nal heatsinks even when delivering high output currents.
Differential sensing enables accurate control of the out-
put voltage, while adaptive voltage positioning provides
optimum transient response. An internal regulator
enables operation with input voltage ranges of +4.75V to
+5.5V or +8V to +28V. The high switching frequency, up
to 500kHz per phase, and dual-phase operation allow
the use of low-output inductor values and input capacitor
values. This accommodates the use of PC board-
embedded planar magnetics achieving superior reliabili-
ty, current sharing, thermal management, compact size,
and low system cost.
The MAX5038/MAX5041 also feature a clock input
(CLKIN) for synchronization to an external clock, and a
clock output (CLKOUT) with programmable phase delay
(relative to CLKIN) for paralleling multiple phases. The
MAX5038 offers a variety of factory-trimmed preset output
voltages (see
Selector Guide)
and the MAX5041 offers an
adjustable output voltage from +1.0V to +3.3V.
The MAX5038/MAX5041 operate over the extended
industrial temperature range (-40°C to +85°C) and are
available in a 28-pin SSOP package. Refer to the
MAX5037 data sheet for a VRM 9.0-compatible, VID-
controlled output voltage controller in a 44-pin MQFP or
QFN package.
Features
♦
+4.75V to +5.5V or +8V to +28V Input Voltage
Range
♦
Up to 60A Output Current
♦
Internal Voltage Regulator for a +12V or +24V
Power Bus
♦
True Differential Remote Output Sensing
♦
Two Out-Of-Phase Controllers Reduce Input
Capacitance Requirement and Distribute Power
Dissipation
♦
Average Current-Mode Control
Superior Current Sharing Between Individual
Phases and Paralleled Modules
Accurate Current Limit Eliminates MOSFET and
Inductor Derating
♦
Integrated 4A Gate Drivers
♦
Selectable Fixed Frequency 250kHz or 500kHz Per
Phase (Up to 1MHz for 2 Phases)
♦
Fixed (MAX5038) or Adjustable (MAX5041) Output
Voltages
♦
0.5% Accurate Reference (MAX5041B)
♦
External Frequency Synchronization from 125kHz
to 600kHz
♦
Internal PLL with Clock Output for Paralleling
Multiple DC-DC Converters
♦
Thermal Protection
♦
28-Pin SSOP Package
MAX5038/MAX5041
Applications
Servers and Workstations
Point-Of-Load High-Current/High-Density
Telecom DC-DC Regulators
Networking Systems
Large-Memory Arrays
RAID Systems
High-End Desktop Computers
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
28 SSOP
28 SSOP
28 SSOP
28 SSOP
28 SSOP
28 SSOP
28 SSOP
OUTPUT
VOLTAGE
Fixed +1.2V
Fixed +1.5V
Fixed +1.8V
Fixed +2.5V
Fixed +3.3V
Adj +1.0V to
+3.3V
Adj +1.0V to
+3.3V
MAX5038EAI12
-40°C to +85°C
MAX5038EAI15
MAX5038EAI18
MAX5038EAI25
MAX5038EAI33
MAX5041EAI
MAX5041BEAI
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
Pin Configuration appears at end of data sheet.
________________________________________________________________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.
Dual-Phase, Parallelable, Average Current-Mode
Controllers
MAX5038/MAX5041
ABSOLUTE MAXIMUM RATINGS
IN to SGND.............................................................-0.3V to +30V
BST_ to SGND…………………………………….…-0.3V to +35V
DH_ to LX_ ................................-0.3V to [(V
BST
_ - V
LX
_) + 0.3V]
DL_ to PGND ..............................................-0.3V to (V
CC
+ 0.3V)
BST_ to LX_ ..............................................................-0.3V to +6V
V
CC
to SGND............................................................-0.3V to +6V
V
CC
to PGND............................................................-0.3V to +6V
SGND to PGND .....................................................-0.3V to +0.3V
All Other Pins to SGND...............................-0.3V to (V
CC
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
28-Pin SSOP (derate 9.5mW/°C above +70°C) ............762mW
Operating Temperature Range ...........................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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
CC
= +5V, circuit of Figure 1, T
A
= -40°C to +85°C, unless otherwise noted. Typical specifications are at T
A
= +25°C.) (Note 1)
PARAMETER
SYSTEM SPECIFICATIONS
8
Input Voltage Range
Quiescent Supply Current
Efficiency
OUTPUT VOLTAGE
MAX5038 only, no load
Nominal Output Voltage
Accuracy
MAX5038 only, no load, V
IN
= V
CC
=
+4.75V to +5.5V or V
IN
= +8V to +28V
(Note 2)
MAX5041 only, no load
SENSE+ to SENSE- Voltage
Accuracy
MAX5041 only, no load, V
IN
= V
CC
=
+4.75V to +5.5V or V
IN
= +8V to +28V
MAX5041B only, no load
MAX5041B only, no load,
V
IN
= +8V to +28V
STARTUP/INTERNAL REGULATOR
V
CC
Undervoltage Lockout
V
CC
Undervoltage Lockout
Hysteresis
V
CC
Output Accuracy
MOSFET DRIVERS
Output Driver Impedance
Output Driver Source/Sink
Current
Non-Overlap Time
R
ON
I
DH
_, I
DL
_
t
NO
C
DH
_
/DL
_ = 5nF
Low or high output
1
4
60
3
Ω
A
ns
V
IN
= +8V to +28V, I
SOURCE
= 0 to 80mA
4.85
UVLO
V
CC
falling
4.0
4.15
200
5.1
5.30
4.5
V
mV
V
-0.8
-1
0.992
0.990
0.995
0.995
+0.8
%
+1
1.008
1.010
1.005
1.005
V
V
IN
I
Q
η
Short IN and V
CC
together for +5V input
operation
EN = V
CC
or SGND
I
LOAD
= 52A (26A per phase)
4.75
4
90
28
5.5
10
V
mA
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
Dual-Phase, Parallelable, Average Current-Mode
Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +5V, circuit of Figure 1, T
A
= -40°C to +85°C, unless otherwise noted. Typical specifications are at T
A
= +25°C.) (Note 1)
PARAMETER
OSCILLATOR AND PLL
Switching Frequency
PLL Lock Range
PLL Locking Time
CLKOUT Phase Shift
(at f
SW
= 125kHz)
CLKIN Input Pulldown Current
CLKIN High Threshold
CLKIN Low Threshold
CLKIN High Pulse Width
PHASE High Threshold
PHASE Low Threshold
PHASE Input Bias Current
CLKOUT Output Low Level
CLKOUT Output High Level
CURRENT LIMIT
Average Current-Limit Threshold
Cycle-by-Cycle Current Limit
Cycle-by-Cycle Overload
Response Time
CURRENT-SENSE AMPLIFIER
CSP_ to CSN_ Input Resistance
Common-Mode Range
Input Offset Voltage
Amplifier Gain
3dB Bandwidth
Transconductance
Open-Loop Gain
Common-Mode Voltage Range
DIFF Output Voltage
Input Offset Voltage
Amplifier Gain
R
CS
_
V
CMR(CS)
V
OS(CS)
A
V(CS)
f
3dB
gm
ca
A
VOL(CE)
V
CMR(DIFF)
V
CM
V
OS(DIFF)
A
V(DIFF)
MAX5038/MAX5041 (+1.2V, +1.5V, +1.8V
output versions)
MAX5038 (+2.5V and +3.3V output versions)
V
SENSE+
= V
SENSE-
= 0
-1
0.997
0.495
1
0.5
No load
-0.3
0.6
+1
1.003
0.505
-0.3
-1
18
4
550
50
+1.0
4
+3.6
+1
kΩ
V
mV
V/V
MHz
µS
dB
V
V
mV
V/V
V
CL
V
CLPK
t
R
CSP_ to CSN_
CSP_ to CSN_ (Note 3)
V
CSP
_ to V
CSN
_ = +150mV
45
90
48
112
260
51
130
mV
mV
ns
f
SW
f
PLL
t
PLL
PHASE = V
CC
115
85
55
3
2.4
0.8
200
4
1
-50
I
SINK
= 2mA (Note 2)
4.5
+50
100
CLKIN = SGND
CLKIN = V
CC
238
475
125
200
120
90
60
5
125
95
65
7
µA
V
V
ns
V
V
µA
mV
V
degrees
PHASE = unconnected
PHASE = SGND
I
CLKIN
V
CLKINH
V
CLKINL
t
CLKIN
V
PHASEH
V
PHASEL
I
PHASEBIA
V
CLKOUTL
V
CLKOUTH
I
SOURCE
= 2mA (Note 2)
250
500
262
525
600
kHz
kHz
µs
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5038/MAX5041
φ
CLKOUT
CURRENT-ERROR AMPLIFIER (TRANSCONDUCTANCE AMPLIFIER)
DIFFERENTIAL VOLTAGE AMPLIFIER (DIFF)
_______________________________________________________________________________________
3
Dual-Phase, Parallelable, Average Current-Mode
Controllers
MAX5038/MAX5041
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +5V, circuit of Figure 1, T
A
= -40°C to +85°C, unless otherwise noted. Typical specifications are at T
A
= +25°C.) (Note 1)
PARAMETER
3dB Bandwidth
Minimum Output Current Drive
SENSE+ to SENSE- Input
Resistance
Open-Loop Gain
Unity-Gain Bandwidth
EAN Input Bias Current
Error-Amplifier Output Clamping
Voltage
THERMAL SHUTDOWN
Thermal Shutdown
Thermal-Shutdown Hysteresis
EN INPUT
EN Input Low Voltage
EN Input High Voltage
EN Pullup Current
V
ENL
V
ENH
I
EN
3
4.5
5
5.5
1
V
V
µA
T
SHDN
150
8
°C
°C
SYMBOL
f
3dB
I
OUT(DIFF)
R
VS
_
C
DIFF
= 20pF
1.0
50
100
CONDITIONS
MIN
TYP
3
MAX
UNITS
MHz
mA
kΩ
VOLTAGE-ERROR AMPLIFIER (EAOUT)
A
VOL(EA)
f
UGEA
I
B(EA)
V
EAN
= +2.0V
-100
810
70
3
+100
918
dB
MHz
nA
mV
V
CLAMP(EA)
With respect to V
CM
Note 1:
Specifications from -40°C to 0°C are guaranteed by characterization but not production tested.
Note 2:
Guaranteed by design. Not production tested.
Note 3:
See
Peak-Current Comparator
section.
4
_______________________________________________________________________________________
Dual-Phase, Parallelable, Average Current-Mode
Controllers
MAX5038/MAX5041
Typical Operating Characteristics
(Circuit of Figure 1. T
A
= +25°C, unless otherwise noted.)
EFFICIENCY vs. OUTPUT CURRENT AND
INTERNAL OSCILLATOR FREQUENCY
MAX5038/41 toc01
EFFICIENCY vs. OUTPUT CURRENT
AND INPUT VOLTAGE
MAX5038/41 toc02
EFFICIENCY vs. OUTPUT CURRENT
90
80
70
MAX5038/41 toc03
100
90
80
η
(%)
70
60
50
40
100
90
80
70
V
IN
= +12V
V
IN
= +5V
100
f = 500kHz
f = 250kHz
η
(%)
η
(%)
60
50
40
30
20
60
50
40
30
20
V
IN
= +5V
V
OUT
= +1.8V
0 4 8 12 16 20 24 28 32 36 40 44 48 52
I
OUT
(A)
10
0
V
OUT
= +1.8V
f
SW
= 250kHz
0 4 8 12 16 20 24 28 32 36 40 44 48 52
I
OUT
(A)
10
0
V
IN
= +24V
V
OUT
= +1.8V
f
SW
= 125kHz
0 4 8 12 16 20 24 28 32 36 40 44 48 52
I
OUT
(A)
EFFICIENCY vs. OUTPUT CURRENT
AND OUTPUT VOLTAGE
MAX5038/41 toc04
EFFICIENCY vs. OUTPUT CURRENT
AND OUTPUT VOLTAGE
MAX5038/41 toc05
SUPPLY CURRENT
vs. FREQUENCY AND INPUT VOLTAGE
12.0
11.5
11.0
10.5
I
CC
(mA)
10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
6.0
V
IN
= +12V
MAX5038/41 toc06
100
90
80
70
η
(%)
60
50
40
30
20
10
0
V
IN
= +12V
f
SW
= 250kHz
V
OUT
= +1.1V
V
OUT
= +1.5V
V
OUT
= +1.8V
100
90
80
70
η
(%)
60
50
40
30
20
10
0
V
IN
= +5V
f
SW
= 500kHz
V
OUT
= +1.1V
V
OUT
= +1.5V
V
OUT
= +1.8V
V
IN
= +24V
V
IN
= +5V
EXTERNALCLOCK
NO DRIVER LOAD
0 4 8 12 16 20 24 28 32 36 40 44 48 52
I
OUT
(A)
0 4 8 12 16 20 24 28 32 36 40 44 48 52
I
OUT
(A)
100 150 200 250 300 350 400 450 500 550 600
FREQUENCY (kHz)
SUPPLY CURRENT
vs. TEMPERATURE AND FREQUENCY
MAX5038/41 toc07
SUPPLY CURRENT
vs. TEMPERATURE AND FREQUENCY
MAX5038/41 toc08
SUPPLY CURRENT
vs. LOAD CAPACITANCE PER DRIVER
90
80
70
I
CC
(mA)
60
50
40
MAX5038/41 toc09
100
90
80
70
I
CC
(mA)
250kHz
175
600kHz
150
125
500kHz
100
50
40
30
20
10
0
V
IN
= +12V
C
DL_
= 22nF
C
DH_
= 8.2nF
-40
-15
10
125kHz
I
CC
(mA)
60
100
75
50
25
V
IN
= +5V
C
DL_
= 22nF
C
DH_
= 8.2nF
-40
-15
10
35
60
85
30
20
10
0
1
3
5
7
9
11
13
15
TEMPERATURE (°C)
C
DRIVER
(nF)
V
IN
= +12V
f
SW
= 250kHz
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
5