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19-3034; Rev 0; 10/03
Dual-Phase, Parallelable, Average-Current-Mode
Controllers
General Description
The MAX5038A/MAX5041A dual-phase, PWM controllers
provide high-output-current capability in a compact
package with a minimum number of external compo-
nents. The MAX5038A/MAX5041A 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 MAX5038A/MAX5041A 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
MAX5038A/MAX5041A also limit the reverse current in
case the bus voltage becomes higher than the regulat-
ed output voltage. The MAX5038A offers a variety of fac-
tory-trimmed preset output voltages (see
Selector Guide)
and the MAX5041A offers an adjustable output voltage
between +1.0V to +3.3V.
The MAX5038A/MAX5041A operate over the extended
temperature range (-40°C to +85°C) and are available
in a 28-pin SSOP package. Refer to the MAX5037A and
MAX5065/MAX5067 data sheets for a VRM 9.0/VRM 9.1-
compatible, VID-controlled, adjustable output voltage
controller in a 44-pin MQFP/thin QFN or 28-pin SSOP
package.
Features
o
+4.75V to +5.5V or +8V to +28V Input Voltage
Range
o
Up to 60A Output Current
o
Internal Voltage Regulator for a +12V or +24V
Power Bus
o
True Differential Remote Output Sensing
o
Two Out-Of-Phase Controllers Reduce Input
Capacitance Requirement and Distribute Power
Dissipation
o
Average-Current-Mode Control
Superior Current Sharing Between Individual
Phases and Paralleled Modules
Accurate Current Limit Eliminates MOSFET and
Inductor Derating
o
Limits Reverse-Current Sinking in Paralleled
Modules
o
Integrated 4A Gate Drivers
o
Selectable Fixed Frequency 250kHz or 500kHz per
Phase (Up to 1MHz for Two Phases)
o
Fixed (MAX5038A) or Adjustable (MAX5041A)
Output Voltages
o
External Frequency Synchronization from 125kHz
to 600kHz
o
Internal PLL with Clock Output for Paralleling
Multiple DC-DC Converters
o
Thermal Protection
o
28-Pin SSOP Package
MAX5038A/MAX5041A
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
PART
MAX5038A
EAI12
MAX5038AEAI15
MAX5038AEAI18
MAX5038AEAI25
MAX5038AEAI33
MAX5041AEAI
Ordering Information
TEMP RANGE
-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-
PACKAGE
28 SSOP
28 SSOP
28 SSOP
28 SSOP
28 SSOP
28 SSOP
OUTPUT
VOLTAGE
(V)
Fixed +1.2
Fixed +1.5
Fixed +1.8
Fixed +2.5
Fixed +3.3
Adj +1.0 to
+3.3
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
MAX5038A/MAX5041A
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
MAX5038A only, no load
Nominal Output Voltage
Accuracy (Note 4)
MAX5038A only, no load, V
IN
= V
CC
=
+4.75V to +5.5V or V
IN
= +8V to +28V
(Note 2)
MAX5041A only, no load
MAX5041A only, no load, V
IN
= V
CC
=
+4.75V to +5.5V or V
IN
= +8V to +28V
UVLO
V
CC
rising
-0.8
-1
0.992
0.990
+0.8
%
+1
1.008
V
1.010
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
SENSE+ to SENSE- Voltage
Accuracy (Note 4)
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
Nonoverlap Time
OSCILLATOR AND PLL
Switching Frequency
PLL Lock Range
PLL Locking Time
f
SW
f
PLL
t
PLL
R
ON
I
DH
_, I
DL
_
t
NO
4.0
4.15
200
4.5
V
mV
V
IN
= +8V to +28V, I
SOURCE
= 0 to 80mA
Low or high output
4.85
5.1
1
4
5.30
3
V
Ω
A
ns
C
DH
_
/DL
_ = 5nF
CLKIN = SGND
CLKIN = V
CC
238
475
125
60
250
500
200
262
525
600
kHz
kHz
µs
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
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
Reverse 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
3dB Bandwidth
Minimum Output Current Drive
SENSE+ to SENSE- Input
Resistance
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)
f
3dB
I
OUT(DIFF)
R
VS
_
MAX5038A (+1.2V, +1.5V, +1.8V output
versions), MAX5041A
MAX5038A (+2.5V and +3.3V output versions)
C
DIFF
= 20pF
1.0
50
100
V
SENSE+
= V
SENSE-
= 0
-1
0.997
0.495
1
0.5
3
No load
-0.3
0.6
+1
1.003
0.505
MHz
mA
kΩ
-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
CLR
V
CLPK
t
R
CSP_ to CSN_
CSP_ to CSN_
CSP_ to CSN_ (Note 3)
V
CSP
_ to V
CSN
_ = +150mV
45
-3.9
90
112
260
48
51
-0.2
130
mV
mV
mV
ns
SYMBOL
PHASE = V
CC
CONDITIONS
PHASE = unconnected
PHASE = SGND
I
CLKIN
V
CLKINH
V
CLKINL
t
CLKIN
V
PHASEH
V
PHASEL
I
PHASEBIA
V
CLKOUTL
I
SINK
= 2mA (Note 2)
4.5
V
CLKOUTH
I
SOURCE
= 2mA (Note 2)
-50
200
4
1
+50
100
MIN
115
85
55
3
2.4
0.8
TYP
120
90
60
5
MAX
125
95
65
7
µA
V
V
ns
V
V
µA
mV
V
Degrees
UNITS
MAX5038A/MAX5041A
φ
CLKOUT
CURRENT-ERROR AMPLIFIER (TRANSCONDUCTANCE AMPLIFIER)
DIFFERENTIAL VOLTAGE AMPLIFIER (DIFF)
_______________________________________________________________________________________
3
Dual-Phase, Parallelable, Average-Current-Mode
Controllers
MAX5038A/MAX5041A
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
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
A
VOL(EA)
f
UGEA
I
B(EA)
V
EAN
= +2.0V
-100
810
CONDITIONS
MIN
TYP
70
3
+100
918
MAX
UNITS
dB
MHz
nA
mV
VOLTAGE-ERROR AMPLIFIER (EAOUT)
V
CLAMP(EA)
With respect to V
CM
Note 1:
Note 2:
Note 3:
Note 4:
Specifications from -40°C to 0°C are guaranteed by characterization but not production tested.
Guaranteed by design. Not production tested.
See
Peak-Current Comparator
section.
Does not include an error due to finite error amplifier gain (see the
Voltage-Error Amplifier
section).
4
_______________________________________________________________________________________