LTM4661 [Linear]
15V, 4A Step-Up μModule Regulator;
| 型号： | LTM4661 |
| 厂家： | 
Linear |
| 描述： | 15V, 4A Step-Up μModule Regulator |
| 文件： | 总20页 (文件大小：646K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTM4661
15V, 4A Step-Up
µModule Regulator
FEATURES
DESCRIPTION
2
The LTM®4661 is a synchronous step-up switching mode
µModule® (powermodule)regulatorina6.25mm×6.25mm
× 2.42mm BGA package. Included in the package are the
switching controller, power FETs, inductor and all support
components. Operating over an input voltage of 1.8V to
5.5V, down to 0.7V after start-up, the LTM4661 regulates
anoutputvoltageof2.5Vto15Vsetbyanexternalresistor.
It provides up to 4A switch current. Only bulk input and
output capacitors are needed.
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Complete Solution in <1cm (Single-Sided PCB) or
2
0.5cm (Dual-Sided PCB)
Input Voltage Range: 1.8V to 5.5V, Down to 0.7V
After Start-Up
Output Voltage Range: 2.5V to 15V
4A Switch Current
Dual Phase Operation
3ꢀ Maꢁimum ꢂotal DC Output Voltage Regulation
Over Load, Line and ꢂemperature
Output Disconnect in Shut Down
Inrush Current Limit
External Frequency Synchronization
Selectable Burst Mode® Operation
Output Overvoltage and Overtemperature Protection
6.25mm × 6.25mm × 2.42mm BGA package
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The LTM4661 1MHz switching frequency and dual phase
singleoutputarchitectureenablefasttransientresponseto
lineandloadchangesandasignificantreductionofoutput
ripple voltage. It supports frequency synchronization,
PolyPhase® operationandselectableBurstModeoperation.
The LTM4661 features a true output disconnect during
shutdown and inrush current limit at start-up. It also has
short-circuit,overvoltageandovertemperatureprotection.
APPLICATIONS
n
RF Microwave Power Amplifiers
The LTM4661 is Pb-free and RoHS compliant.
All registered trademarks and trademarks are the property of their respective owners.
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Battery Powered DC Motors
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3.3V Bus Telecom Transceivers
TYPICAL APPLICATION
5V/2A DC/DC Step-Up µModule Regulator
Efficiency vs Output Current at 3.3V Input
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4661f
1
For more information www.linear.com/LTM4661
LTM4661
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(See Pin Functions, Pin Configuration ꢂable)
(Note 1)
ꢎꢊꢌ ꢏꢍꢑꢡ
V
V
.............................................................. –0.3V to 6V
OUT
IN
ꢏ
ꢊꢢꢎ
........................................................... –0.3V to 18V
ꢃꢄꢅ
ꢆꢅ
COMP, FREQ ........................................ –0.3V to INTVCC
SYNC/MODE, SDB ....................................... –0.3V to 6V
Operating Internal Temperature Range
(Note 2) ............................................. –40°C to 125°C
Storage Temperature Range .................. –55°C to 125°C
Peak Solder Reflow Body Temperature.................250°C
ꢂ
4
ꢁ
ꢀ
1
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ꢇꢈꢄ
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ꢕ
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ꢀꢂꢗꢘꢙꢚꢛ ꢜ6ꢝꢀꢂꢞꢞ ꢟ 6ꢝꢀꢂꢞꢞ ꢟ ꢀꢝ4ꢀꢞꢞꢠ
T
JMAX
= 125°C, θ
= 17°C/W, θ
= 11°C/W,
JCtop
JCbottom
θ
+ θ = 22°C/W, θ = 22°C/W
JB
BA JA
WEIGHT = 0.25g
http://www.linear.com/product/LꢂM4661#orderinfo
ORDER INFORMATION
PARꢂ MARKING*
PACKAGE
MSL
RAꢂING
ꢂEMPERAꢂURE RANGE
(Note 2)
PARꢂ NUMBER
LTM4661EY#PBF
LTM4661IY#PBF
LTM4661IY
PAD OR BALL FINISH
SAC305 (RoHS)
SAC305 (RoHS)
SnPb (63/37)
DEVICE
FINISH CODE
ꢂYPE
BGA
BGA
BGA
LTM4661Y
LTM4661Y
LTM4661Y
e1
e1
e0
4
4
4
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
• Consult Marketing for parts specified with wider operating temperature
ranges. *Pad or ball finish code is per IPC/JEDEC J-STD-609.
• Recommended BGA PCB Assembly and Manufacturing Procedures:
www.linear.com/umodule/pcbassembly
• Terminal Finish Part Marking: www.linear.com/leadfree
• BGA Package and Tray Drawings: www.linear.com/packaging
4661f
2
For more information www.linear.com/LTM4661
LTM4661
ELECTRICAL CHARACTERISTICS ꢂhe l denotes the specifications which apply over the specified internal
operating temperature range, otherwise specifications are at ꢂA = 25°C (Note 2), VIN = 3.3V, per the typical application.
SYMBOL
PARAMEꢂER
CONDIꢂIONS
MIN
ꢂYP
MAX UNIꢂS
Switching Regulator Section: per Channel
l
l
l
l
V
V
V
V
Input DC Voltage
V
V
≥ 2.5V
= 0V
0.7
5.5
1.8
15
V
IN
OUT
OUT
Minimum Start-Up Voltage
Output Voltage Range
1.6
5
IN(MIN)
OUT(RANGE)
OUT(DC)
2.5
V
V
Output Voltage, Total
Variation with Line and Load
R
V
= 31.6k, SYNC/MODE = INTV
= 3.3V, V
4.85
5.15
FB
IN
CC
= 5V, I
= 0A to 2A
OUT
OUT
I
Input Supply Bias Current
V
V
= 3.3V, V
= 3.3V, V
= 5V, SYNC/MODE = INTV , I = 5mA
CC OUT
10
8.5
0.5
mA
mA
µA
Q(VIN)
IN
IN
OUT
OUT
= 5V, SYNC/MODE = GND, I
= 5mA
OUT
Shutdown, SDB = 0, V = 3.3V
IN
I
I
Input Supply Current
V
= 3.3V, V
= 5V, I = 2A
OUT
3.7
A
S(VIN)
IN
OUT
Output Continuous Current
Range
V
V
= 3.3V, V
= 3.3V, V
= 5V (Note 4)
= 12V
0
0
2
0.7
A
A
OUT(DC)
IN
IN
OUT
OUT
l
l
ΔV
ΔV
(Line)/V
Line Regulation Accuracy
Load Regulation Accuracy
Output Ripple Voltage
V
V
= 12V, V = 1.8V to 5.5V, I = 0A
OUT
0.1
0.1
3
0.5
2
%/V
%
OUT
OUT
OUT
IN
(Load)/V
= 3.3V, V
= 5V, I
= 0A to 2A
OUT
OUT
IN
OUT
OUT
V
I
= 0A, C = 2×22µF Ceramic
OUT
mV
OUT(AC)
OUT
V
= 3.3V, V
= 5V
IN
OUT
ΔV
Turn-On Overshoot
Turn-On Time
I
= 0A, C = 2×22µF Ceramic,
OUT
30
10
mV
ms
mV
uS
OUT(START)
OUT
IN
V
= 3.3V, V
= 5V
OUT
t
C
= 100µF Ceramic,
START
OUT
No Load, V = 3.3V, V
= 5V
IN
OUT
ΔV
OUTLS
Peak Deviation for Dynamic Load: 0% to 25% to 0% of Full Load
Load
200
500
C
= 100µF Ceramic, V = 3.3V, V
= 5V
OUT
IN
OUT
t
Settling Time for Dynamic
Load Step
Load: 0% to 25% to 0% of Full Load
C
SETTLE
= 100µF Ceramic, V = 3.3V, V
= 5V
OUT
IN
OUT
l
V
Voltage at V Pin
I
= 0A, V = 3.3V, V
= 5V, SYNC/MODE = INTV
CC
1.17
99.5
1.2
1
1.23
50
V
nA
kΩ
FB
FB
OUT
IN
OUT
I
FB
Current at V Pin
(Note 7)
FB
R
Resistor Between V
and
100
100.5
FBHI
OUT
V
FB
Pins
Duty(MIN)
Duty(MAX)
Minimum Duty Cycle
Maximum Duty Cycle
FB = 1.4V (Note 7)
FB = 1.0V (Note 7)
0
%
%
90
94
SDB Input Voltage
SDB Input High
SDB Input Low
1.2
0.35
V
V
I
SDB Input Current
SDB = 5.5V
1
4.25
1
2
uA
V
SDB
V
Internal V Voltage
V
IN
< 2.8V, V >5V
3.9
0.5
4.6
INTVCC
OSC
CC
OUT
f
Switching Frequency
MHz
MHz
SYNC Range
MODE/SYNC
SYNC Frequency Range
1.5
2
Sync Input High Voltage
Sync Input Low Voltage
1.6
0.35
V
V
I
SDB = 5.5V
1
uA
MODE/SYNC
4661f
3
For more information www.linear.com/LTM4661
LTM4661
ELECTRICAL CHARACTERISTICS
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 3: The minimum on-time condition is specified for a peak-to-peak
inductor ripple current of ~40% of I
Information section)
Load. (See the Applications
MAX
Note 4: See output current derating curves for different V , V
and T .
A
IN OUT
Note 2: The LTM4661 is tested under pulsed load conditions such that
Note 5: Limit current into the RUN pin to less than 2mA.
Note 6: Guaranteed by design.
T ≈ T . The LTM4661E is guaranteed to meet performance specifications
J
A
over the 0°C to 125°C internal operating temperature range. Specifications
over the full –40°C to 125°C internal operating temperature range are
assured by design, characterization and correlation with statistical process
controls. The LTM4661I is guaranteed to meet specifications over the
full –40°C to 125°C internal operating temperature range. Note that the
maximum ambient temperature consistent with these specifications is
determined by specific operating conditions in conjunction with board
layout, the rated package thermal resistance and other environmental
factors.
Note 7: 100% tested at wafer level.
Note 8: The LTM4661 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 170°C when overtemperature shutdown is active.
Continuous operation above the specified maximum operation junction
temperature may result in device degradation or failure.
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency vs Output Current,
VIN = 3.3V
Efficiency vs Output Current,
VIN = 5V
Burst vs Continuous Mode
Efficiency, VIN = 3.3V
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4661 ꢗꢌ1
4661 ꢗꢌꢘ
4661 ꢖꢌꢗ
5V Output Load ꢂransient
Response
12V Output Load ꢂransient
Response
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4661 ꢕꢁ4
4661 ꢕꢁꢀ
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f ꢗ 1ꢛꢜꢝ ꢋꢅꢓꢞꢌꢉꢑꢊꢎ
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4661f
4
For more information www.linear.com/LTM4661
LTM4661
TYPICAL PERFORMANCE CHARACTERISTICS
Start-Up Waveform with No Load
Applied
Steady State Output Ripple
ꢆ
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1ꢁꢇꢄꢅꢆꢇ
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4661 ꢐꢁ6
4661 ꢐꢁꢑ
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ꢀꢁꢁꢂꢃꢄꢅꢆꢇ
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ꢎꢍꢏ
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ꢒ ꢀꢇ
ꢒ 1ꢉꢇ
f
ꢒ 1ꢗꢘꢙ ꢋꢅꢚꢛꢌꢉꢜꢊꢎ
f ꢒ 1ꢗꢘꢙ ꢚꢅꢛꢜꢋꢍꢝꢏꢞ
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ꢟ
ꢒ ꢉꢠꢉꢉꢂꢜ ꢟꢛꢌꢋꢗꢆꢟ
ꢎꢍꢏ
ꢈꢉꢊ
Start-Up Waveform with 0.5A
Load Applied
Short-Circuit Response
ꢇ
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4661 ꢐꢁꢑ
4661 ꢍꢁꢎ
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f ꢏ 1ꢕꢖꢗ ꢘꢅꢙꢚꢉꢋꢛꢌꢜ
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ꢊꢋꢌ
ꢎꢍꢏ
4661f
5
For more information www.linear.com/LTM4661
LTM4661
PIN FUNCTIONS
V (A1, B1, C1, D1, E1): Power Input Pins. Apply input
is regulated at the lower of V and 4.25V. When V falls
IN IN
IN
voltage between these pins and GND pins. Recommend
below 3V and V
is higher than V , INTV will regulate
OUT
IN
OUT
CC
placinginput decouplingcapacitance directlybetweenV
pins and GND pins.
to the lower of approximately V
event occurs if INTV drops below 1.5V, typical.
and 4.25V. A UVLO
IN
CC
V
(A4, A5, B5, C5): Power Output Pins of the Switch-
FREQ (E3): Frequency Set Internally to 1MHz. An external
OUꢂ
ing Mode Regulator. Apply output load between these pins
and GND pins. Recommend placing output decoupling
capacitance directly between these pins and GND pins.
resistor can be placed from this pin to ground to increase
frequency or from this pin to INTV to reduce frequency.
CC
See the Applications Information section for frequency
adjustment.
GND (A2, A3, B2 to B4, C2 to C4, D4, E2): Power Ground
Pins for Both Input and Output Returns.
SDB (D5): Shutdown Control Input of the µModule
Regulator. Pulling this pin above 1.6V enables normal,
free-running operation. Forcing this pin below 0.25V
shuts the regulator off, with quiescent current below
1µA. Do not leave this pin floating.
SYNC/MODE (D2): Burst Mode Operation Selection Pin
and External Synchronization Input to Phase Detector
Pin. Connect this pin to INTV to operate the module
CC
in forced continuous mode. Connect this pin to GND to
enable Burst Mode operation. A clock more than 100ns
on the pin will force the module operating in continuous
mode and synchronized to the external clock applied to
this pin. The external clock frequency must be higher than
the self-running frequency programmed by FREQ pin. See
frequency programming in the Applications Information
section.
COMP(E4):CurrentControlThresholdandErrorAmplifier
Compensation Point of the Switching Mode Regulator. Tie
the COMP pins together for parallel operation. The device
is internal compensated.
FB (E5): The Negative Input of the Error Amplifier for the
SwitchingModeRegulator.Internally,thispinisconnected
to V
with a 100kΩ 0.5% precision resistor. Different
OUT
INꢂV (D3):InternalRegulatorOutput.Theinternalpower
output voltages can be programmed with an additional
resistorbetweenFBandGNDpins.InPolyPhaseoperation,
tyingtheFBpinstogetherallowsforparalleloperation.See
the Applications Information section for details.
CC
drivers and control circuits are powered from this volt-
age. Decouple this pin to power ground with a minimum
of 2.2µF low ESR ceramic capacitor. The INTV voltage
CC
4661f
6
For more information www.linear.com/LTM4661
LTM4661
BLOCK DIAGRAM
ꢅ
ꢋꢑꢄ
1ꢛꢛꢚ
ꢀꢁ
ꢒ1ꢓ6ꢚ
ꢕꢓꢕꢗꢟ
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ꢆꢋꢊꢎ
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ꢕꢙꢚ
4661 ꢁꢌ
OPERATION
The LTM4661 is a dual-phase single-output standalone
non-isolatedstep-upswitchingmodeDC/DCpowersupply.
This module provides a precisely regulated output voltage
programmable via one external resistor from 1.2V to 15V
and provides up to 4A switch current (see Table 1) with
few external input and output ceramic capacitors. It also
offers the unique ability to start up from inputs as low as
1.8V and continue to operate from inputs as low as 0.7V
for output voltages greater than 2.5V. The typical applica-
tion schematic is shown in Figure 17.
resistors and the µModule regulator can be externally
synchronized to a clock at least 100ns minimum.
With current mode control and internal feedback loop
compensation, the LTM4661 module has sufficient stabil-
ity margins and good transient performance with a wide
range of output capacitors, even with all ceramic output
capacitors.
Pulling the SDB pin above 1.6V enables module opera-
tion and forcing it below 0.25V shuts the module off with
quiescent current below 1µA. At light load currents, Burst
Modeoperationcanbeenabledtoachievehigherefficiency
comparedtocontinuousmode(CCM)bysettingtheSYNC/
MODEpintoGND.Aninternal10mssoft-startlimitsinrush
current during start-up and simplifies the design process
while minimizing the number of external components.
The LTM4661 contains an integrated fixed frequency, cur-
rent mode regulator, power MOSFETs, inductor and other
supporting discrete components. The default switching
frequency is 1MHz. For switching noise-sensitive applica-
tions, the switching frequency can be adjusted by external
4661f
7
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
The typical LTM4661 application circuit is shown in
Figure 17. External component selection is primarily de-
termined by the input voltage, the output voltage and the
maximum load current.
Based on common input and output values, Table 1 lists
differentoutputcurrentcapabilityoftheLTM4661module.
ꢂable 1. Output Current Capability vs Input Voltage
V
V
(V)
3.3
5
12
1
IN
(V)
5
1.9
82
4
8
1
12
0.7
83
15
0.5
81
4
8
15
0.7
88
OUꢂ
Minimum Input Voltage
Output Current (A)
Efficiency (%)
1.7
88
The LTM4661 is designed to allow start-up from input
84
3.8
87
voltages as low as 1.8V. When V
exceeds 2.5V, the
Peak Switch Current (A)
3.9
3.94 4.1
4.1
OUT
LTM4661 continues to regulate its output, even when V
IN
falls as low as 0.7V. This feature extends operating times
by maximizing the amount of energy that can be extracted
from the input source. The limiting factors for the applica-
tion become the availability of the power source to supply
sufficient power to the output at the low input voltage,
and the maximum duty cycle, which is clamped at 94%.
Output Voltage Programming
The PWM controller has an internal 1.2V reference volt-
age. As shown in the Block Diagram, a 100k 0.5% internal
feedback resistor connects V
and FB pins together.
OUT
Adding a resistor R from FB pin to GND, programs the
FB
output voltage:
In a step-up boost converter, the duty cycle can be cal-
culated at:
1.2V
R
=
• 100k
FB
V
– 1.2V
OUT
V • η
IN
D = 1–
ꢂable 2. VFB Resistor Value vs Various Output Voltages
V
OUT
V
(V)
1.2
2.5
3.3
5
8
12
15
OUꢂ
whereηistheconverterefficiency.85%isagoodestimate
R
(k)
OPEN 93.1
57.6
31.6
17.8
11.0
8.66
FB
to start with.
ForparalleloperationofN-pieceofLTM4661modules,the
following equation can be used to solve for R :
Notethatatlowinputvoltages, voltagedropsduetoseries
resistance become critical and greatly limit the power
delivery capability of the converter.
FB
1.2V
– 1.2V
100k
N
R
=
•
FB
V
OUT
Output Current Capability
Multiphase Operation
The LTM4661 is designed to provide up to 4A switch cur-
rent. Due to the nature of the boost converter, the actually
output current capability depends highly on the input/
output voltage ratio. The peak inductor current, same as
switch current, in a boost converter can be calculated as:
The LTM4661 uses a unique dual-phase single-output
architecture, rather than the conventional single phase of
otherboostconverters.Byinterleavingtwophasesequally
spaced 180° apart, both input and output current ripple
get significantly reduced as well as the amount of input
and output decoupling capacitor required.
V • D
I
OUT
IN
I
=
+
SW
2 • f • L 1– D
S
where D is the duty cycle showing above and f = 1MHz
S
and L = 2.2µH/2 = 1.1µH.
4661f
8
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
ꢑꢒꢓ
from the input source. As a result, the duration of the
soft-start is largely unaffected by the size of the output
capacitor or the output regulation voltage. The soft-start
period is reset by a shutdown command on SDB, a UVLO
ꢖꢁꢏꢗꢍꢃ ꢋꢘꢐꢖꢃ
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1ꢒꢓ
1ꢒꢈ
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ꢋꢘꢐꢖꢃ
event on INTV (INTV < 1.5V), an overvoltage event on
CC
CC
V
(V
≥ 16.5V), or an overtemperature event (TSD is
OUT OUT
invoked when the die temperature exceeds 170°C). Upon
removal of these fault conditions, the LTM4661 will soft-
start the output voltage.
ꢈ
ꢈꢒꢓ
1ꢒꢈ
1ꢒꢓ
Burst Mode Operation
ꢀꢁꢂꢃ ꢄꢅꢆꢇ
4661 ꢕꢈ1
In applications where high efficiency at light load current
aremoreimportantthanoutputvoltageripple,BurstMode
operationcouldbeusedbyconnectingSYNC/MODEpinto
GND to improve light load efficiency. The output current
Figure 1. Comparison of Output Ripple Current with
Single Phase and Dual Phase Boost Converter
Input Decoupling Capacitors
(I ) capability in Burst Mode operation is significantly
OUT
The LTM4661 module should be connected to a low AC-
impedance DC source. For each module, one piece 10µF
input ceramic capacitor is required for RMS ripple current
decoupling. Bulk input capacitor is only needed when the
inputsourceimpedanceiscompromisedbylonginductive
leads, traces or not enough source capacitance. The bulk
capacitor can be an electrolytic aluminum capacitor and
polymer capacitor.
less than in continuous current mode (CCM) and varies
with V and V , as shown in Figure 2. The LTM4661
IN
OUT
will operate in CCM mode even if Burst Mode operation
is commanded during soft-start.
In Burst Mode operation, only one phase of the LTM4661
isoperational,whiletheotherphaseisdisabled.Thephase
inductor current is initially charged to approximately
700mA by turning on the N-channel MOSFET switch,
at which point the N-channel switch is turned off and
the P-channel synchronous switch is turned on, deliv-
ering current to the output. When the inductor current
discharges to approximately zero, the cycle repeats. In
Output Decoupling Capacitors
With an optimized high frequency, high bandwidth, two
phase interleaving design, only single piece of 22µF low
ESRoutputceramiccapacitorisrequiredforeachLTM4661
module to achieve low output voltage ripple and very
good transient response. Additional output filtering may
be required by the system designer, if further reduction of
outputripplesordynamictransientspikesisrequired. The
LTpowerCAD® Design Tool is available to download online
foroutputripple, stabilityandtransientresponseanalysis.
4ꢓꢓ
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ꢒꢓꢓ
ꢕꢔꢓ
ꢕꢓꢓ
1ꢔꢓ
1ꢓꢓ
ꢔꢓ
Soft-Start
The LTM4661 contains internal circuitry to provide soft-
start operation. The soft-start utilizes a linearly increasing
ramp of the error amplifier reference voltage from zero
to its nominal value of 1.2V in approximately 10ms, with
ꢓ
ꢓꢖꢔ
1
1ꢖꢔ
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ꢕꢖꢔ
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4
4ꢖꢔ
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ꢀ
ꢃ ꢄꢅꢆꢆꢁꢂꢇ ꢈꢀꢉ
4661 ꢄꢓꢕ
ꢁꢂ
ꢀ
ꢀ
ꢀ
ꢗ ꢕꢖꢔꢀ
ꢗ ꢔꢀ
ꢗ ꢘꢖꢔꢀ
ꢀ
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ꢗ 1ꢕꢀ
ꢗ 1ꢔꢀ
ꢊꢋꢌ
ꢊꢋꢌ
ꢊꢋꢌ
ꢊꢋꢌ
ꢊꢋꢌ
the internal control loop driving V
from zero to its final
OUT
programmed value. This limits the inrush current drawn
Figure 2. Burst Mode Output Current vs VIN
4661f
9
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
Burst Mode operation, energy is delivered to the output
until the nominal regulation value is reached, then the
LTM4661 transitions into a very low quiescent current
sleep state. In sleep, the output switches are turned off
and the LTM4661 consumes only 25µA of quiescent
current. When the output voltage droops approximately
1%, switching resumes. This maximizes efficiency at
very light loads by minimizing switching and quiescent
losses. Output voltage ripple in Burst Mode operation
is typically 1% to 2% peak-to-peak. Additional output
capacitance (22µF or greater), or the addition of a small
feedforwardcapacitor(10pF to50pF)connectedbetween
Shutdown
The boost converter is disabled by pulling SDB below
0.25V and enabled by pulling SDB above 1.6V. Note that
SDB pin can be driven above V or V , as long as it is
limited to less than its absolute maximum rating.
IN
OUT
ꢂhermal Shutdown
Ifthedietemperatureexceeds170°Ctypical,theLTM4661
will go into thermal shutdown (TSD). All switches will be
shut off until the die temperature drops by approximately
7°C, when the device reinitiates a soft-start and switching
is re-enabled.
V
and FB, can help further reduce the output ripple.
OUT
Output Disconnect
Operation Frequency
TheLTM4661’soutputdisconnectfeatureeliminatesbody
diode conduction of the internal P-channel MOSFET recti-
The operating frequency of the LTM4661 is optimized to
achievethecompactpackagesizeandtheminimumoutput
ripplevoltagewhilestillkeepinghighefficiency.Thedefault
operating frequency is internally set to 1MHz. In most ap-
plications, no additional frequency adjusting is required.
fiers.ThisfeatureallowsforV
todischargeto0Vduring
OUT
shutdownanddrawnocurrentfromtheinputsource.Inrush
current will also be limited at turn-on, minimizing surge
currents seen by the input supply. The output disconnect
If any operating frequency other than 1MHz is required by
application, the operating frequency can be increased by
feature also allows V
to be pulled high, without back-
OUT
feeding the power source connected to V .
IN
adding a resistor, R
, between the FREQ pin and GND,
FSET
as shown in Figure 18. The operating frequency can be
Short-Circuit Protection
calculated as:
The LTM4661 output disconnect feature allows output
short-circuit protection while maintaining a maximum set
current limit. To reduce power dissipation under overload
andshort-circuitconditions,thepeakswitchcurrentlimits
28 +R
kΩ
(
)
FSET
f MHz =
(
)
s
R
kΩ
(
)
FSET
are reduced to approximately 2A. Once V
exceeds
OUT
Frequency Synchronization
approximately 1.5V, the current limits are reset to their
nominal values of 3.5A peak switching current per phase.
The switching frequency of the LTM4661 can be synchro-
nized to a desired frequency by applying a clock of twice
the desired frequency to the SYNC/MODE pin. Also, the
freerunningfrequencyneedstobeadjustedtoafrequency
approximately80%ofthedesiredfrequency.Pleaseusethe
equation in the Operation Frequency section to calculate
Output Overvoltage Protection
An overvoltage condition occurs when V
exceeds
OUT
approximately 16.5V. Switching is disabled and the in-
ternal soft-start ramp is reset. Once V drops below
OUT
the external R
resistor value.
FSET
approximately 16V, a soft-start is initiated and switching
is allowed to resume. If the boost converter output is
lightly loaded such that the time constant of the output
For example, if the LTM4661 needs to be synchronized to
1.5MHz switching frequency, an external clock of 3MHz
needs to supply to SYNC/MODE pin while adding a 140kΩ
capacitance, C
and the output load resistance, R
is
OUT
OUT
near or greater than the soft-start time of approximately
10ms, the soft-start ramp may end before or soon after
R
resistor between FREQ pin and GND to program the
FSET
free run frequency to 1.2MHz.
4661f
10
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
switchingresumes,defeatingtheinrushcurrentlimitingof
the closed-loop soft-start following an overvoltage event.
2. θ
, the thermal resistance from junction to
JCbottom
ambient,isthenaturalconvectionjunction-to-ambient
air thermal resistance measured in a one cubic foot
sealed enclosure. This environment is sometimes
referred to as “still air” although natural convection
causes the air to move. This value is determined with
the part mounted to a JESD51-9 defined test board,
which does not reflect an actual application or viable
operating condition.
ꢂhermal Considerations and Output Current Derating
The thermal resistances reported in the Pin Configuration
section of the data sheet are consistent with those param-
eters defined by JESD51-9 and are intended for use with
finite element analysis (FEA) software modeling tools that
leveragetheoutcomeofthermalmodeling,simulationand
correlationtohardwareevaluationperformedonaµModule
package mounted to a hardware test board—also defined
by JESD51-9 (“Test Boards for Area Array Surface Mount
Package Thermal Measurements”). The motivation for
providingthesethermalcoefficientsinfoundinJESD51-12
(“Guidelines for Reporting and Using Electronic Package
Thermal Information”).
3. θ
, the thermal resistance from junction to top of
JCtop
the product case, is determined with nearly all of the
componentpowerdissipationflowingthroughthetop
of the package. As the electrical connections of the
typical µModule are on the bottom of the package, it
is rare for an application to operate such that most of
the heat flows from the junction to the top of the part.
As in the case of θ
, this value may be useful
JCbottom
Many designers may opt to use laboratory equipment
and a test vehicle such as the demo board to anticipate
the µModule regulator’s thermal performance in their ap-
plicationatvariouselectricalandenvironmentaloperating
conditions to compliment any FEA activities. Without FEA
software, the thermal resistances reported in the Pin Con-
figuration section are in and of themselves not relevant to
providing guidance of thermal performance; instead, the
derating curves provided in the data sheet can be used in
a manner that yields insight and guidance pertaining to
one’s application usage and can be adapted to correlate
thermal performance to one’s own application.
for comparing packages but the test conditions don’t
generally match the user’s application.
4. θ , the thermal resistance from junction to the
JB
printed circuit board, is the junction-to-board thermal
resistance where almost all of the heat flows through
the bottom of the µModule and into the board, and
is really the sum of the θ
and the thermal re-
JCbottom
sistance of the bottom of the part through the solder
joints and through a portion of the board. The board
temperature is measured a specified distance from
the package, using a two sided, two layer board. This
board is described in JESD51-9.
The Pin Configuration section typically gives four thermal
coefficients explicitly defined in JESD51-12; these coef-
ficients are quoted or paraphrased below:
A graphical representation of the aforementioned ther-
mal resistances is given in Figure 3; blue resistances are
contained within the µModule regulator, whereas green
resistances are external to the µModule.
1. θ , the thermal resistance from junction to ambi-
JA
ent, is the natural convection junction-to-ambient
air thermal resistance measured in a one cubic foot
sealed enclosure. This environment is sometimes
referred to as “still air” although natural convection
causes the air to move. This value is determined with
the part mounted to a JESD51-9 defined test board,
which does not reflect an actual application or viable
operating condition.
As a practical matter, it should be clear to the reader that
no individual or subgroup of the four thermal resistance
parameters defined by JESD51-12 or provided in the Pin
Configuration section replicates or conveys normal op-
erating conditions of a μModule. For example, in normal
board-mounted applications, never does 100% of the
device’s total power loss (heat) thermally conduct exclu-
sivelythroughthetoporexclusivelythroughbottomofthe
4661f
11
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
ꢍꢇꢎꢌꢏꢋꢅꢎꢐꢏꢅꢐꢑꢄꢗꢋꢉꢎꢏ ꢖꢉꢒꢋꢒꢏꢑꢎꢌꢉ ꢓꢍꢉꢒꢆ ꢘ1ꢐꢙ ꢆꢉꢀꢋꢎꢉꢆ ꢗꢅꢑꢖꢆꢕ
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ꢖꢉꢒꢋꢒꢏꢑꢎꢌꢉ
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ꢖꢉꢒꢋꢒꢏꢑꢎꢌꢉ
ꢗꢅꢑꢖꢆꢐꢏꢅꢐꢑꢄꢗꢋꢉꢎꢏ
ꢖꢉꢒꢋꢒꢏꢑꢎꢌꢉ
4661 ꢀꢁꢂ
ꢃꢄꢅꢆꢇꢈꢉ ꢆꢉꢊꢋꢌꢉ
Figure 3. Graphical Representation of JESD51-12 ꢂhermal Coefficients
µModule—asthestandarddefinesforθ
andθ
,
chamber while operating the device at the same power
loss as that which was simulated. An outcome of this
process and due diligence yields a set of derating curves
provided in other sections of this data sheet. After these
laboratory tests have been performed and correlated to
JCtop
JCbottom
respectively.Inpractice,powerlossisthermallydissipated
in both directions away from the package—granted, in
the absence of a heat sink and airflow, a majority of the
heat flow is into the board.
the µModule model, then the θ and θ are summed
JB
BA
Within a SIP (system-in-package) module, be aware there
are multiple power devices and components dissipating
power, with a consequence that the thermal resistances
relative to different junctions of components or die are not
exactly linear with respect to total package power loss. To
reconcile this complication without sacrificing modeling
simplicity—but also, not ignoring practical realities—an
approach has been taken using FEA software modeling
along with laboratory testing in a controlled-environment
chamber to reasonably define and correlate the thermal
resistance values supplied in this data sheet: (1) Initially,
FEA software is used to accurately build the mechanical
geometry of the µModule and the specified PCB with all
of the correct material coefficients along with accurate
power loss source definitions; (2) this model simulates
a software-defined JEDEC environment consistent with
JESD51-9topredictpowerlossheatflowandtemperature
readingsatdifferentinterfacesthatenablethecalculationof
theJEDEC-definedthermalresistancevalues;(3)themodel
and FEA software is used to evaluate the µModule with
heat sink and airflow; (4) having solved for and analyzed
these thermal resistance values and simulated various
operating conditions in the software model, a thorough
laboratory evaluation replicates the simulated conditions
with thermocouples within a controlled-environment
togethertocorrelatequitewellwiththeµModulemodelwith
no airflow or heat sinking in a properly defined chamber.
This θ + θ value is shown in the Pin Configuration
JB
BA
section and should accurately equal the θ value because
JA
approximately 100% of power loss flows from the junc-
tion through the board into ambient with no airflow or top
mounted heat sink.
The 5V, 8V, 12V and 15V output power loss curves in
Figures 4 to 7 can be used in coordination with the load
current derating curves in Figures 8 to 14 for calculating
an approximate θ thermal resistance for the LTM4661
JA
with various heat sinking and airflow conditions. The
power loss curves are taken at room temperature and
are increased with multiplicative factors according to the
ambient temperature. These approximate factors is 1.4
assuming the junction temperature at 110°C. The output
voltages are chosen to include the lower and higher out-
put voltage ranges for correlating the thermal resistance.
Thermal models are derived from several temperature
measurementsinacontrolledtemperaturechamberalong
withthermalmodelinganalysis.Thejunctiontemperatures
are monitored while ambient temperature is increased
with and without airflow. The power loss increase with
ambient temperature change is factored into the derating
4661f
12
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
curves. The junctions are maintained at 110°C maximum
while lowering output current or power with increasing
ambient temperature. The decreased output current will
decrease the internal module loss as ambient temperature
isincreased.Themonitoredjunctiontemperatureof110°C
minus the ambient operating temperature specifies how
much module temperature rise can be allowed. As an ex-
ample, in Figure 13 the load current is derated to ~0.35A
at ~80°C with no air or heat sink and the power loss for
the 3.3V to 15V at 0.35A output is about 1.4W. The 1.4W
loss is calculated with the ~1.0W room temperature loss
from the 3.3V to 15V power loss curve at 0.35A, and the
1.4 multiplying factor. If the 80°C ambient temperature
is subtracted from the 110°C junction temperature, then
the difference of 30°C divided by 1.4W equals a 21.4°C/W
θ
thermal resistance. Table 3 specifies a 21°C/W value
JA
which is very close. Table 3 to Table 6 provide equivalent
thermal resistances for 5V, 8V, 12V and 15V outputs with
and without airflow and heat sinking. The derived thermal
resistances in Tables 3 to 6 for the various conditions can
be multiplied by the calculated power loss as a function
of ambient temperature to derive temperature rise above
ambient, thus maximum junction temperature. Room
temperature power loss can be derived from the efficiency
curves in the Typical Performance Characteristics section
and adjusted with the above ambient temperature mul-
tiplicative factors. The printed circuit board is a 1.6mm
thick four layer board with two ounce copper for the two
outer layers and one ounce copper all four layers. The
PCB dimensions are 65mm × 65mm.
ꢐ
ꢒꢑꢓ
ꢒꢑ6
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1ꢑꢓ
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ꢌꢑ4
ꢕꢑꢕꢖ ꢗꢈꢍꢅꢉ
ꢔꢖ ꢗꢈꢍꢅꢉ
ꢕꢑꢕꢘ ꢙꢈꢍꢅꢉ
ꢓꢘ ꢙꢈꢍꢅꢉ
ꢌꢑꢐ
ꢌ
ꢐꢑꢐꢕ ꢖꢈꢍꢅꢉ
ꢌ
ꢌꢑꢒ ꢌꢑ4 ꢌꢑ6 ꢌꢑꢓ
1
1ꢑꢒ 1ꢑ4 1ꢑ6 1ꢑꢓ
ꢒ
ꢌ
ꢌꢑꢐ ꢌꢑ4 ꢌꢑ6 ꢌꢑꢒ
1
1ꢑꢐ 1ꢑ4 1ꢑ6 1ꢑꢒ
ꢐ
ꢌ
ꢌꢑ1 ꢌꢑꢐ ꢌꢑꢕ ꢌꢑ4 ꢌꢑꢓ ꢌꢑ6 ꢌꢑꢖ ꢌꢑꢒ ꢌꢑꢔ
ꢀꢁꢂꢃ ꢄꢅꢆꢆꢇꢈꢉ ꢊꢂꢋ
4661 ꢗꢌ6
1
ꢀꢁꢂꢃ ꢄꢅꢆꢆꢇꢈꢉ ꢊꢂꢋ
ꢀꢁꢂꢃ ꢄꢅꢆꢆꢇꢈꢉ ꢊꢂꢋ
4661 ꢔꢌ4
4661 ꢓꢌꢔ
Figure 4. 5V Output Power Loss
Figure 5. 8V Output Power Loss
Figure 6. 12V Output Power Loss
ꢓꢔꢕ
ꢓ
1ꢓꢔ
1
ꢐ
1ꢑꢒ
1ꢑ6
1ꢑ4
1ꢑꢐ
1
ꢏꢓꢕ
ꢏꢓ6
ꢏꢓ4
ꢏꢓꢔ
ꢏ
1ꢔꢕ
1
ꢌꢑꢒ
ꢌꢑ6
ꢌꢑ4
ꢌꢑꢐ
ꢌ
ꢏꢔꢕ
ꢏ
ꢏꢐꢗꢁ
ꢓꢏꢏꢐꢗꢁ
4ꢏꢏꢐꢗꢁ
ꢏꢐꢖꢁ
ꢔꢏꢏꢐꢖꢁ
4ꢏꢏꢐꢖꢁ
ꢕꢑꢕꢘ ꢙꢈꢍꢅꢉ
ꢓꢘ ꢙꢈꢍꢅꢉ
ꢎꢏ 4ꢏ ꢕꢏ 6ꢏ ꢘꢏ ꢖꢏ ꢙꢏ 1ꢏꢏ 11ꢏ
ꢎꢏ 4ꢏ ꢙꢏ 6ꢏ ꢘꢏ ꢕꢏ ꢗꢏ 1ꢏꢏ 11ꢏ
ꢌ
ꢌꢑ1 ꢌꢑꢐ ꢌꢑꢕ ꢌꢑ4 ꢌꢑꢓ ꢌꢑ6 ꢌꢑꢖ ꢌꢑꢒ ꢌꢑꢔ
ꢀꢁꢂꢃ ꢄꢅꢆꢆꢇꢈꢉ ꢊꢂꢋ
1
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
4661 ꢗꢏꢖ
4661 ꢖꢏꢗ
4661 ꢗꢌꢖ
Figure 7. 15V Output Power Loss
Figure 8. 3.3V to 5V Derating
Curve, No Heat Sink
Figure 9. 3.3V to 8V Derating
Curve, No Heat Sink
4661f
13
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
1ꢓꢔ
1ꢓ6
1ꢓ4
1ꢓꢕ
1ꢓꢏ
ꢏꢓꢔ
ꢏꢓ6
ꢏꢓ4
ꢏꢓꢕ
ꢏ
ꢏꢓꢔ
ꢏꢓꢕ
ꢏꢓ6
ꢏꢓꢖ
ꢏꢓ4
ꢏꢓꢎ
ꢏꢓꢗ
ꢏꢓ1
ꢏ
1ꢓꢔ
1
ꢏꢓꢕ
ꢏꢓ6
ꢏꢓ4
ꢏꢓꢔ
ꢏ
ꢏꢐꢖꢁ
ꢕꢏꢏꢐꢖꢁ
4ꢏꢏꢐꢖꢁ
ꢏꢐꢙꢁ
ꢔꢏꢏꢐꢙꢁ
4ꢏꢏꢐꢙꢁ
ꢏꢐꢘꢁ
ꢗꢏꢏꢐꢘꢁ
4ꢏꢏꢐꢘꢁ
ꢎꢏ 4ꢏ ꢘꢏ 6ꢏ ꢗꢏ ꢔꢏ ꢙꢏ 1ꢏꢏ 11ꢏ
ꢎꢏ 4ꢏ ꢖꢏ 6ꢏ ꢕꢏ ꢔꢏ ꢙꢏ 1ꢏꢏ 11ꢏ
ꢎꢏ 4ꢏ ꢗꢏ 6ꢏ ꢖꢏ ꢕꢏ ꢘꢏ 1ꢏꢏ 11ꢏ
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
4661 ꢖ1ꢏ
4661 ꢘ11
4661 ꢙ1ꢔ
Figure 10. 5V Input to 8V Output
Derating Curve, No Heat Sink
Figure 11. 3.3V Input to 12V Output
Derating Curve, No Heat Sink
Figure 12. 5V Input to 12V Output
Derating Curve, No Heat Sink
ꢏꢓ6
ꢏꢓꢔ
ꢏꢓ4
ꢏꢓꢎ
ꢏꢓꢕ
ꢏꢓꢔ
ꢏꢓꢕ
ꢏꢓꢖ
ꢏꢓ6
ꢏꢓꢘ
ꢏꢓ4
ꢏꢓꢎ
ꢏꢓꢗ
ꢏꢐꢙꢁ
ꢗꢏꢏꢐꢙꢁ
4ꢏꢏꢐꢙꢁ
ꢏꢓ1
ꢏ
ꢏꢐꢗꢁ
ꢕꢏꢏꢐꢗꢁ
4ꢏꢏꢐꢗꢁ
ꢏꢓ1
ꢏ
ꢎꢏ 4ꢏ ꢔꢏ 6ꢏ ꢘꢏ ꢖꢏ ꢙꢏ 1ꢏꢏ 11ꢏ
ꢎꢏ 4ꢏ ꢘꢏ 6ꢏ ꢖꢏ ꢕꢏ ꢔꢏ 1ꢏꢏ 11ꢏ
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
ꢀꢁꢂꢃꢄꢅꢆ ꢆꢄꢁꢇꢄꢈꢀꢆꢉꢈꢄ ꢊꢋꢌꢍ
4661 ꢗ1ꢎ
4661 ꢙ14
Figure 13. 3.3V Input to 15V Output
Derating Curve, No Heat Sink
Figure 14. 5V Input to 15V Output
Derating Curve, No Heat Sink
4661f
14
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
ꢂable 3. 5V Output
DERAꢂING CURVE
Figure 8
V
(V)
POWER LOSS CURVE
Figure 4
AIR FLOW (LFM)
HEAꢂ SINK
None
Θ
Θ
Θ
Θ
(°C/W)
21
IN
JA
JA
JA
JA
3.3
3.3
3.3
0
Figure 8
Figure 4
200
400
None
19
Figure 8
Figure 4
None
18
ꢂable 4. 8V Output
DERAꢂING CURVE
Figures 9, 10
V
(V)
POWER LOSS CURVE
Figure 5
AIR FLOW (LFM)
HEAꢂ SINK
None
(°C/W)
21
IN
3.3, 5
3.3, 5
3.3, 5
0
Figures 9, 10
Figure 5
200
400
None
19
Figures 9, 10
Figure 5
None
18
ꢂable 5. 12V Output
DERAꢂING CURVE
Figures 11, 12
V
(V)
POWER LOSS CURVE
Figure 6
AIR FLOW (LFM)
HEAꢂ SINK
None
(°C/W)
21
IN
3.3, 5
3.3, 5
3.3, 5
0
Figures 11, 12
Figure 6
200
400
None
19
Figures 11, 12
Figure 6
None
18
ꢂable 6. 15V Output
DERAꢂING CURVE
Figures 13, 14
V
(V)
POWER LOSS CURVE
Figure 7
AIR FLOW (LFM)
HEAꢂ SINK
None
(°C/W)
21
IN
3.3, 5
3.3, 5
3.3, 5
0
Figures 13, 14
Figure 7
200
400
None
19
Figures 13, 14
Figure 7
None
18
4661f
15
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
Figure 15 shows a measured thermal picture of the
LTM4661 running from 3.3V input to 12V output at 0.8A
DC current with 200LFM airflow and no heat sink.
•
Placehighfrequencyceramicinputandoutputcapaci-
tors next to the V , PGND and V
pins to minimize
IN
OUT
high frequency noise.
•
•
Place a dedicated power ground layer underneath the
unit.
Tominimizetheviaconductionlossandreducemodule
thermal stress, use multiple vias for interconnection
between top layer and other power layers.
•
•
Do not put vias directly on the pad, unless they are
capped or plated over.
For parallel modules, tie the V , V and COMP
OUT FB
pins together. Use an internal layer to closely connect
these pins together.
•
Bringouttestpointsonthesignalpinsformonitoring.
Figure 15. ꢂhermal Image, 3.3V Input to 12V Output at 0.8A,
200LFM Air Flow, No Heat Sink
Figure16givesagoodexampleoftherecommendedlayout.
Safety Considerations
ꢃꢂꢄ
The LTM4661 modules do not provide galvanic isolation
from V to V . There is no internal fuse. If required,
IN
OUT
a slow blow fuse with a rating twice the maximum input
current needs to be provided to protect each unit from
catastrophic failure. The device does support thermal
shutdown and overcurrent protection.
ꢀꢁꢂ
Layout Checklist/Eꢁample
ꢀꢅꢆꢇ
The high integration of LTM4661 makes the PCB board
layoutverysimpleandeasy.However,tooptimizeitselectri-
cal and thermal performance, some layout considerations
are still necessary.
ꢃꢂꢄ
4661 ꢈ16
•
Use large PCB copper areas for high current paths,
including V , GND and V . It helps to minimize the
Figure 16. Recommended PCB Layout
IN
OUT
PCB conduction loss and thermal stress.
4661f
16
For more information www.linear.com/LTM4661
LTM4661
APPLICATIONS INFORMATION
ꢆꢍꢘꢚ ꢀꢁꢑꢛ
ꢐꢃꢑ4661
ꢈ
ꢈ
ꢁꢂꢃ
ꢓꢈꢔꢄꢕ
ꢉꢊ
ꢈ
ꢉꢊ
ꢈ
ꢁꢂꢃ
ꢌꢋꢌꢈ
ꢀ
ꢀ
ꢁꢂꢃ
ꢄꢄꢅꢆ ꢇꢄ
16ꢈ
ꢉꢊ
ꢖꢗꢒ
ꢑꢁꢗꢘꢔꢖꢙꢊꢀ
ꢉꢊꢃꢈ
ꢄꢄꢅꢆ ꢇꢄ
6ꢋꢌꢈ
ꢆꢒ
ꢀꢀ
ꢍ1
ꢌ1ꢋ6ꢎ
ꢜꢊꢗ
ꢄꢋꢄꢅꢆ
4661 ꢆ1ꢏ
Figure 17. 3.3V Input to 5V Output, at 2A Design
14ꢐꢏ
ꢆꢎꢚꢛ ꢀꢁꢒꢢ
ꢉ
ꢉ
ꢁꢂꢃ
1ꢄꢉꢞꢐꢌꢑꢠ
ꢊꢋ
ꢉ
ꢉ
ꢁꢂꢃ
ꢊꢋ
ꢍꢌꢍꢉ ꢃꢁ ꢈꢉ
ꢀ
ꢀ
ꢁꢂꢃ
ꢄꢄꢅꢆ ꢇꢄ
ꢄꢈꢉ
ꢊꢋ
ꢗꢡꢟ
ꢄꢄꢅꢆ ꢇꢄ
6ꢌꢍꢉ
ꢕꢃꢒ4661
ꢍꢒꢓꢔ ꢀꢕꢁꢀꢖ
ꢒꢁꢡꢚꢞꢗꢜꢋꢀ
ꢊꢋꢃꢉ
ꢆꢟ
ꢎꢄ
ꢙꢋꢡ
ꢀꢀ
11ꢏ
ꢄꢌꢄꢅꢆ
4661 ꢆ1ꢑ
ꢗꢘꢊꢃꢀꢓꢊꢋꢙ ꢆꢎꢚꢛꢂꢚꢋꢀꢜ ꢝ ꢀꢕꢁꢀꢖ ꢆꢎꢚꢛꢂꢚꢋꢀꢜꢞꢄ
Figure 18. 3.3V to 5V Input, 12V Output Design with Eꢁternal Clock
ꢎꢒꢗꢔ
ꢂꢟꢑꢠ ꢎꢒꢗꢔ
ꢅ
ꢅ
ꢒꢚꢍ
ꢈꢅꢣꢀꢖ
ꢜꢝ
ꢅ
ꢅ
ꢜꢝ
ꢒꢚꢍ
ꢂꢤ
ꢇꢆꢇꢅ ꢍꢒ ꢄꢅ
ꢀꢀꢁꢂ ꢃꢀ
6ꢆꢇꢅ
ꢀꢀꢁꢂ ꢃꢀ
ꢀꢄꢅ
ꢐꢥꢤ
ꢌꢍꢗ4661
ꢈꢇꢆꢄꢊ
ꢗꢒꢥꢑꢣꢐꢡꢝꢎ
ꢜꢝꢍꢅ
ꢞꢝꢥ
1
ꢀ
ꢇ
4
ꢄ
1ꢏ
ꢋ
ꢜꢝꢍꢅ
ꢜꢝꢍꢅ
ꢎꢎ
ꢅꢦ
ꢐꢑꢍ
ꢎꢎ
ꢎꢎ
1ꢁꢂ
ꢀꢆꢀꢁꢂ
ꢥꢜꢅ
ꢗꢒꢥ
ꢈ
ꢎꢒꢗꢔ
ꢂꢟꢑꢠ ꢎꢒꢗꢔ
ꢔꢕ ꢌꢍꢎ6ꢋꢏꢀ ꢞꢝꢥ
ꢉ
ꢒꢚꢍ1
ꢒꢚꢍꢀ
ꢒꢚꢍ4
ꢒꢚꢍꢇ
ꢅ
ꢅ
ꢜꢝ
ꢒꢚꢍ
6
ꢀꢀꢁꢂ ꢃꢀ
6ꢆꢇꢅ
ꢀꢀꢁꢂ ꢃꢀ
ꢀꢄꢅ
ꢐꢥꢤ
ꢌꢍꢗ4661
ꢌꢍꢎ6ꢈꢏꢀ ꢐꢑꢍ ꢍꢒ
ꢀꢓꢔꢕꢖꢐꢑ ꢀꢆ4ꢗꢕꢘ ꢎꢌꢒꢎꢙ ꢒꢚꢍꢔꢚꢍ
ꢗꢒꢥꢑꢣꢐꢡꢝꢎ
ꢜꢝꢍꢅ
ꢂꢤ
ꢞꢝꢥ
ꢎꢎ
ꢈꢆꢈꢉꢊ
ꢀꢆꢀꢁꢂ
ꢐꢛꢜꢍꢎꢕꢜꢝꢞ ꢂꢟꢑꢠꢚꢑꢝꢎꢡ ꢢ ꢎꢌꢒꢎꢙ ꢂꢟꢑꢠꢚꢑꢝꢎꢡꢣꢀ
4661 ꢂ1ꢋ
Figure 19. ꢂwo LꢂM4661 Module Parallel Design for 8V/2A Output Running at 1.2MHz
4661f
17
For more information www.linear.com/LTM4661
LTM4661
PACKAGE DESCRIPTION
PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCꢂS. REVIEW EACH PACKAGE
LAYOUꢂ CAREFULLY.
LꢂM4661 Component BGA Pinout
PIN ID
A1
FUNCꢂION
PIN ID
A2
FUNCꢂION
GND
PIN ID
A3
FUNCꢂION
GND
PIN ID
A4
FUNCꢂION
PIN ID
A5
FUNCꢂION
V
IN
V
IN
V
IN
V
IN
V
IN
V
V
V
V
OUT
OUT
OUT
OUT
B1
B2
GND
B3
GND
B4
GND
GND
GND
COMP
B5
C1
C2
GND
C3
GND
C4
C5
D1
D2
SYNC/MODE D3
GND E3
INTV
D4
D5
SDB
FB
CC
E1
E2
FREQ
E4
E5
4661f
18
For more information www.linear.com/LTM4661
LTM4661
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/product/LꢂM4661#packaging for the most recent package drawings.
ꢒ
ꢒ
ꢶ ꢶ ꢩ ꢩ ꢩ ꢒ
ꢜ ꢛ ꢝ 4 ꢚ
1 ꢛ ꢜ ꢞ ꢚ
ꢚ ꢛ ꢗ 1 ꢞ ꢝ
ꢚ ꢛ ꢚ ꢚ ꢚ
ꢚ ꢛ ꢗ 1 ꢞ
1 ꢛ ꢜ ꢞ ꢚ
ꢜ ꢛ ꢝ 4 ꢚ
4661f
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
19
subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
For more information www.linear.com/LTM4661
LTM4661
PACKAGE PHOTO
DESIGN RESOURCES
SUBJECꢂ
DESCRIPꢂION
µModule Design and Manufacturing Resources
Design:
Manufacturing:
• Selector Guides
• Quick Start Guide
• Demo Boards and Gerber Files
• Free Simulation Tools
• PCB Design, Assembly and Manufacturing Guidelines
• Package and Board Level Reliability
µModule Regulator Products Search
1. Sort table of products by parameters and download the result as a spread sheet.
2. Search using the Quick Power Search parametric table.
TechClip Videos
Quick videos detailing how to bench test electrical and thermal performance of µModule products.
Digital Power System Management
Analog Devices’s family of digital power supply management ICs are highly integrated solutions that
offer essential functions, including power supply monitoring, supervision, margining and sequencing,
and feature EEPROM for storing user configurations and fault logging.
RELATED PARTS
PARꢂ NUMBER
LTM8054
DESCRIPꢂION
COMMENꢂS
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5V ≤ V ≤ 36V, 1.2V ≤ V
≤ 36V, 11.25mm × 15mm × 3.42mm BGA
IN
IN
OUT
LTM8045
SEPIC (Boost) or Inverting µModule Regulator
2.8V ≤ V ≤ 18V. 2.5V ≤ V
≤
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is up to 700mA.
is up to 1.5A,
IN
OUT
OUT
6.25mm × 11.25mm x 4.92mm BGA
LTM8049
LTM4622
LTM4643
Dual, SEPIC (Boost) and/or Inverting µModule
Regulator
2.6V ≤ V ≤ 20V, 2.5V ≤ V 24V, I
≤
OUT
IN
OUT
9mm × 15mm × 2.42mm BGA
3.6V ≤ V ≤ 20V, 0.6V ≤ V ≤ 5.5V, 6.25mm × 6.25mm × 1.82mm LGA,
OUT
Ultrathin, 20V , Dual 2.5A Step-Down µModule
IN
IN
Regulator
6.25mm × 6.25mm × 2.42mm BGA
Ultrathin, 20V , Quad 3A Step-Down µModule
4V ≤ V ≤ 20V, 0.6V ≤ V ≤ 3.3V, 9mm × 15mm × 1.82mm LGA,
IN
IN
OUT
Regulator
9mm × 15mm × 2.42mm BGA
4661f
LT 1117 • PRINTED IN USA
www.linear.com/LTM4661
ANALOG DEVICES, INC. 2017
20
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