POWER LOSS
LTM4639
Low V 20A DC/DC
IN
Module Step-Down Regulator
FEATURES DESCRIPTION
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Complete 20A Switch Mode Power Supply The LTM 4639 is a complete 20A output high efficiency
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2.375V to 7V Input Voltage Range (V < 4.5V, switch mode step-down DC/DC Module (micromodule)
IN
Need C Bias) regulator. Included in the package are the switching
PWR
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0.6V to 5.5V Output Voltage Range controller, power FETs, inductor and compensation
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1.5% Maximum Total DC Output Voltage Error components. Operating over an input voltage range from
(40C to 125C) 2.375V to 7V, the LTM4639 supports an output voltage
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Differential Remote Sense Amplifier for Precision range of 0.6V to 5.5V, set by a single external resistor.
Regulation (V 3.3V) Only a few input and output capacitors are needed.
OUT
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Current Mode Control/Fast Transient Response
Current mode operation allows precision current sharing of
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Parallel Multiphase Current Sharing (Up to 80A)
up to four LTM4639 regulators to obtain up to 80A output.
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Frequency Synchronization
High switching frequency and a current mode architecture
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Selectable Pulse-Skipping or Burst Mode Operation
enable a very fast transient response to line and load
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Soft-Start/Voltage Tracking
changes without sacrificing stability. The device supports
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Up to 88% Efficiency (3.3V , 1.5V )
IN OUT
frequency synchronization, multiphase/current sharing,
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Overcurrent Foldback Protection
Burst Mode operation and output voltage tracking for
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Output Overvoltage Protection
supply rail sequencing. A diode-connected PNP transistor
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Internal Temperature Monitor
is included for use as an internal temperature monitor. For
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Overtemperature Protection
up to 20V input operation, please see the LTM4637.
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15mm 15mm 4.92mm BGA Package
The LTM4639 is offered in a 15mm 15mm 4.92mm
APPLICATIONS
BGA package. The LTM4639 is RoHS compliant.
L, LT, LTC, LTM, PolyPhase, Burst Mode, Module, Linear Technology, the Linear logo are
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Telecom Servers and Networking Equipment
registered trademarks and LTpowerCAD is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents,
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Industrial Equipment
including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611, 6677210, 8163643.
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Medical Systems
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High Ambient Temperature Systems
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3.3V Input Systems
TYPICAL APPLICATION
3.3V to 1.5V Efficiency
3.3V , 1.5V , 20A DC/DC Module Regulator
IN OUT
and Power Loss
+5V BIAS 100 4.5
4.0
2.2F
EFFICIENCY
95
1F
V
IN
3.5
3.3V
22F
90 3.0
6.3V C
COMPA
V C EXTV INTV PGOOD
IN PWR CC CC
4 V
180pF OUT
2.5
COMPA 1.5V
V
OUT
85
20A
5k 0.1F
COMPB 2.0
V
OUT_LCL
C *
FF
100F*
+ 680F*
TRACK/SS 180pF
6.3V 80 1.5
DIFF_OUT 2.5V
LTM4639
C = 5V
2 PWR
RUN
2
+
V FREQ = 400kHz 1.0
POWER LOSS
OSNS
f
SET 75
V
0.5
OSNS
100k
MODE_PLLIN
V
+ FB
70 0
TEMP
R ** C *
0 2 4 6 8 10 12 14 16 18 20
FB BOT
TEMP SGND GND OT_TEST
40.2k 22pF
OUTPUT CURRENT (A)
4639 TA01b
* SEE TABLE 5
** SEE TABLE 1
4639 TA01a
4639f
1
For more information www.linear.com/LTM4639
EFFICIENCY (%)LTM4639
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION
(Note 1)
TOP VIEW
V , C , OT_TEST .................................. 0.3V to 10V
IN PWR
MODE_PLLIN COMPB
V , PGOOD, EXTV .......................... 0.3V to 6V INTV TRACK/SS COMPA
OUT_LCL CC CC
V
IN
1 2 3 4 5 6 7 8 9 10 11 12
MODE_PLLIN, f , TRACK/SS,
SET
+ A
RUN
V , V , DIFF_OUT ...................0.3V to INTV
OSNS OSNS CC C
PWR
V B f
IN
SET
V COMPA, COMPB (Note 7) ................. 0.3V to 2.7V
FB, OT_TEST
C
RUN (Note 5) ............................................... 0.3V to 5V
INTV
CC
D
INTV Peak Output Current (Note 6) ..................100mA
CC TEMP
E EXTV
CC
Internal Operating Temperature Range
+
TEMP
PGOOD
F V
FB
(Note 2) .................................................. 40C to 125C
GND
G PGOOD
Storage Temperature Range .................. 55C to 125C
H SGND
Maximum Peak Body Reflow Temperature ........... 245C
+
J V
OSNS
K DIFF_OUT
V
OUT
L V
OUT_LCL
M V
OSNS
BGA PACKAGE
133-LEAD (15mm 15mm 4.92mm)
T = 125C, = 9.5C/W, = 4C/W, = 6.7C/W, = 4.5C/W
J(MAX) JA JCbottom JCtop JB
DERIVED FROM 95mm 76mm PCB WITH 4 LAYERS; WEIGHT = 2.8g
JA
VALUES DETERMINED PER JESD51-12
ORDER INFORMATION
PART MARKING*
PACKAGE MSL TEMPERATURE RANGE
PART NUMBER PAD OR BALL FINISH DEVICE FINISH CODE TYPE RATING (SEE NOTE 2)
LTM4639EY#PBF LTM4639Y
SAC305 (RoHS) e1 BGA 4 40C to 125C
LTM4639IY#PBF LTM4639Y
LTM4639IY SnPb (63/37) LTM4639Y e0 BGA 4 40C to 125C
Consult Marketing for parts specified with wider operating temperature Recommended LGA and BGA PCB Assembly and Manufacturing
Procedures: www.linear.com/umodule/pcbassembly
ranges. *Pad or ball finish code is per IPC/JEDEC J-STD-609.
LGA and BGA Package and Tray Drawings: www.linear.com/packaging
Terminal Finish Part Marking: www.linear.com/leadfree
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified internal
operating temperature range (Note 2), otherwise specifications are at T = 25C. V = 3.3V, C = 5V, per the typical application in
A IN PWR
Figure 22.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
l
V Range Input DC Voltage Range V < 4.5V, C Bias 2.375 7 V
IN IN PWR
C Voltage 4.5 5 6 V
PWR
l
V Range Output DC Voltage Range 0.6 5.5 V
OUT
V Output Voltage, Total C = 22F 3, C = 5V l 1.477 1.50 1.523 V
OUT(DC) IN PWR
Variation with Line and C = 100F Ceramic, 470F POSCAP
OUT
Load R = 40.2k, MODE_PLLIN = GND
FB
V = 2.375V to 7V, I = 0A to 20A (Note 4)
IN OUT
4639f
2
For more information www.linear.com/LTM4639