LTM4619IV [Linear]
Dual, 26VIN, 4A DC/DC μModule Regulator; 双通道， 26VIN ， 4A DC / DCμModule稳压器
| 型号： | LTM4619IV |
| 厂家： | 
Linear |
| 描述： | Dual, 26VIN, 4A DC/DC μModule Regulator |
| 文件： | 总24页 (文件大小：295K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTM4619
Dual, 26V , 4A DC/DC
IN
µModule Regulator
FEATURES
DESCRIPTION
The LTM®4619 is a complete dual 4A step-down switch-
ing mode DC/DC power supply. Included in the package
are the switching controller, power FETs, inductor, and all
supportcomponents. Operatingoverinputvoltageranges
of 4.5V to 26.5V, the LTM4619 supports two outputs with
voltage ranges of 0.8V to 5V, each set by a single external
resistor. Its high efficiency design delivers 4A continuous
current (5A peak) for each output.
n
Complete Standalone Power Supply
n
Wide Input Voltage Range: 4.5V to 26.5V
(EXTV Available for V ≤ 5.5V)
CC
IN
n
Dual 180° Out-of-Phase Outputs with 4A DC
Typical, 5A Peak Output Current for Each
n
n
n
n
n
n
n
n
n
n
n
Dual Outputs with 0.8V to 5V V
Output Voltage Tracking
Range
OUT
1.5ꢀ Total DC Output Error
Current Mode Control/Fast Transient Response
Power Good
Highswitchingfrequencyandacurrentmodearchitecture
enable a very fast transient response to line and load
changes without sacrificing stability. The two outputs are
interleavedwith180°phasetominimizetheripplenoiseand
reduce the I/O capacitors. The device supports frequency
synchronization and output voltage tracking for supply
rail sequencing. Burst Mode operation or pulse-skipping
mode can be selected for light load operations.
Phase-Lockable Fixed Frequency 250kHz to 780kHz
On Board Frequency Synchronization
Parallel Current Sharing
Selectable Burst Mode® Operation
Output Overvoltage Protection
Small Surface Mount Footprint, Low Profile
(15mm × 15mm × 2.8mm) LGA Package
Fault protection features include overvoltage protection,
overcurrent protection and foldback current limit for
short-circuit protection.
APPLICATIONS
n
Telecom and Networking Equipment
The low profile package (2.8mm) enables utilization of
unused space on the bottom of PC boards for high density
point of load regulation. The power module is offered in a
space saving and thermally enhanced 15mm × 15mm ×
2.8mm LGA package. The LTM4619 is Pb-free and RoHS
compliant.
n
Servers
n
Storage Cards
ATCA Cards
Industrial Equipment
Point of Load Regulation
n
n
n
L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and μModule are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
TYPICAL APPLICATION
Dual 4A 3.3V/2.5V DC/DC μModule® Regulator
Efficiency and Power Loss at 12V input
95
90
85
80
75
70
65
60
55
2.0
1.5
1.0
0.5
0
EFFICIENCY
MODE/PLLIN INTV
CC
FREQ/PLLFLTR
5.5V TO 26.5V
V
V
IN
10μF
28k
19.1k
22pF
s2
V
FB1
FB2
22pF
COMP1
COMP2
V
V
OUT2
3.3V/4A
OUT1
LTM4619
V
V
OUT2
OUT1
2.5V/4A
100μF
100μF
TK/SS1
RUN1
TK/SS2
RUN2
POWER LOSS
0.1μF
0.1μF
PGOOD
EXTV
CC
2.5V
3.3V
OUT
OUT
SGND
PGND
4619 TA01a
0
0.5
1
1.5
2
2.5
3
3.5
4
LOAD CURRENT (A)
4619 TA01b
4619f
1
LTM4619
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Note 1)
TOP VIEW
V ............................................................. –0.3V to 28V
IN
M
L
INTV , PGOOD, RUN1, RUN2, EXTV ....... –0.3V to 6V
CC
CC
COMP1, COMP2, V , V , .................... –0.3V to 2.7V
FB1 FB2
K
J
MODE/PLLIN, TK/SS1, TK/SS2,
FREQ/PLLFLTR...................................... –0.3V to INTV
OUT1 OUT2
Internal Operating Temperature Range (Note 2)
CC
V
, V
.................................................. 0.8V to 5V
H
G
F
..........................................................–40°C to 125°C
Junction Temperature ........................................... 125°C
Maximum Reflow Body Temperature .................... 245°C
Storage Temperature Range...................–55°C to 125°C
E
D
C
B
A
1
2
3
4
5
6
7
8
9
10
11
12
LGA PACKAGE
144-LEAD (15mm × 15mm × 2.8mm)
T
= 125°C, θ = 13°C/W, θ = 6°C/W
JA JP
JMAX
θ
JA
DERIVED FROM 95mm × 76mm PCB WITH 4 LAYERS
WEIGHT = 1.7g
ORDER INFORMATION
LEAD FREE FINISH
LTM4619EV#PBF
LTM4619IV#PBF
TRAY
PART MARKING*
LTM4619V
PACKAGE DESCRIPTION
TEMPERATURE RANGE
–40°C to 125°C
LTM4619EV#PBF
LTM4619IV#PBF
144-Lead (15mm × 15mm × 2.8mm) LGA
144-Lead (15mm × 15mm × 2.8mm) LGA
LTM4619V
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
This product is only offered in trays. For more information go to: http://www.linear.com/packaging/
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at TA = 25°C, VIN = 12V. Per typical application in Figure 18. Specified as
each channel. (Note 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
4.5
TYP
MAX
26.5
5.0
UNITS
l
l
V
V
V
Input DC Voltage
Output Voltage Range
Output Voltage
V
V
C
≤ 5.5V, Connect V and INTV Together
V
V
IN(DC)
IN
IN
IN
IN
CC
= 5.5V to 26.5V
0.8
OUT1, 2(RANGE)
OUT1, 2(DC)
= 10μF ×1, C
= 100μF Ceramic, 100μF POSCAP,
OUT
R
= 28.0kΩ
= 12V, V
= 12V, V
SET
V
2.483
2.470
2.52 2.557
2.52 2.570
V
V
= 2.5V, I
= 2.5V, I
= 0A
= 4A
IN
IN
OUT
OUT
OUT
OUT
l
V
Input Specifications
V
Undervoltage Lockout Thresholds
V
V
Rising
Falling
2.00
1.85
2.2
2.0
2.35
2.15
V
V
IN(UVLO)
INTVCC
INTVCC
4619f
2
LTM4619
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at TA = 25°C, VIN = 12V. Per typical application in Figure 18. Specified as
each channel (Note 3).
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
I
Input Inrush Current at Start-Up
I
= 0A, C = 10μF, C
= 100μF, V
= 2.5V
OUT
INRUSH(VIN)
OUT
IN
IN
OUT
V
= 12V
0.25
A
I
Input Supply Bias Current
Input Supply Current
V
V
V
V
= 12V, V
= 12V, V
= 2.5V, Switching Continuous
= 2.5V, Switching Continuous
OUT1
OUT2
30
30
40
40
40
mA
mA
mA
mA
μA
Q(VIN)
IN
IN
IN
IN
OUT1
OUT2
= 26.5V, V
= 26.5V, V
= 2.5V, Switching Continuous
= 2.5V, Switching Continuous
Shutdown, RUN = 0, V = 20V
IN
I
V
IN
V
IN
= 12V, V
= 26.5V, V
= 2.5V, I = 4A
OUT
0.97
0.480
A
A
S(VIN)
OUT
= 2.5V, I
= 4A
OUT
OUT
INTV
Internal V Voltage
V
= 12V, V > 2V, No Load
RUN
4.8
4.5
5
5.2
4
V
V
CC
CC
IN
l
EXTV
EXTV Switchover Voltage
EXTV Ramping Positive
4.7
CC
CC
CC
Output Specifications
I
Output Continuous Current Range
Line Regulation Accuracy
V
V
= 12V, V = 2.5V (Note 5)
OUT
0
A
OUT1, 2(DC)
IN
= 2.5V, V from 6V to 26.5V
0.15
0.25
0.3
0.5
%
%
ΔV
OUT
OUT
IN
OUT1(LINE)
l
I
= 0A For Each Output
V
OUT(NOM)
Line Regulation Accuracy
Load Regulation Accuracy
Load Regulation Accuracy
Output Ripple Voltage
V
= 2.5V, V from 6V to 26.5V
0.15
0.25
0.3
0.5
%
%
ΔV
V
OUT
OUT
IN
OUT2(LINE)
l
l
I
= 0A For Each Output
OUT(NOM)
For Each Output, V
= 2.5V, 0A to 4A (Note 5)
0.6
0.8
%
ΔV
OUT1(LOAD)
OUT
V
IN
= 12V
V
OUT1(NOM)
l
For Each Output, V
= 2.5V, 0A to 4A (Note 5)
0.6
0.8
%
ΔV
OUT2(LOAD)
OUT
V
IN
= 12V
V
OUT2(NOM)
V
I
= 0A, C
= 100μF X5R Ceramic
OUT1, 2(AC)
OUT
OUT
V
V
= 12V, V
= 2.5V
OUT
20
25
mV
mV
IN
IN
= 26.5V, V
= 2.5V
OUT
f
Output Ripple Voltage Frequency
Turn-On Overshoot
I
= 2A, V = 12V, V
= 2.5V
780
kHz
S
OUT
IN
OUT
CC
FREQ/PLLFLTR = INTV
C
= 100μF X5R Ceramic, V
= 2.5V, I
= 2.5V, I
= 0A
= 0A
ΔV
OUT
OUT
OUT
OUT
OUTSTART
V
= 12V
10
10
mV
mV
IN
IN
V
= 26.5V
t
Turn-On Time
C
= 100μF X5R Ceramic, V
OUT
START
OUT
Resistive Load,
V
IN
V
IN
= 12V
= 26.5V
0.250
0.130
ms
ms
Peak Deviation for Dynamic Load Load: 0% to 50% to 0% of Full Load
= 100μF X5R Ceramic,V = 2.5V, V = 12V
ΔV
OUTLS
C
OUT
15
10
mV
μs
OUT
IN
t
Settling Time for Dynamic Load
Step
Load: 0% to 50% to 0% of Full Load
OUT
SETTLE
C
= 100μF X5R Ceramic,V
= 2.5V, V = 12V
OUT IN
I
Output Current Limit
C
= 100μF X5R Ceramic,
OUTPK
OUT
V
= 6V, V
= 2.5V
12
11
A
A
IN
IN
OUT
V
= 26.5V, V
= 2.5V
OUT
Control Section
V , V
FB1 FB2
Voltage at V Pin
I
= 0A, V = 2.5V
OUT
0.792
0.788
0.8
0.8
0.808
0.810
V
FB
OUT
l
I
Soft-Start Charge Current
Maximum Duty Factor
Minimum On-Time
V
= 0V, V = 2.5V
OUT
0.9
1.3
97
90
1.7
μA
%
TK/SS1, 2
TK/SS
DF
In Dropout (Note 4)
(Note 4)
MAX
t
ns
ON(MIN)
4619f
3
LTM4619
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at TA = 25°C, VIN = 12V. Per typical application in Figure 18. Specified as
each channel. (Note 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
450
210
700
TYP
500
250
780
250
MAX
550
290
860
UNITS
kHz
f
f
f
Nominal Frequency
Lowest Frequency
Highest Frequency
MODE/PLLIN Input Resistance
V
V
V
= 1.2V
= 0V
NOM
LOW
HIGH
FREQ
FREQ
FREQ
kHz
≥ 2.4V
kHz
R
kꢀ
MODE/PLLIN
FREQ
I
Frequency Setting
Sinking Current
Sourcing Current
f
f
> f
< f
–13
13
μA
μA
MODE
MODE
OSC
OSC
V
RUN Pin ON/OFF Threshold
RUN Rising
RUN Falling
1.1
1.02
1.22
1.14
1.35
1.27
V
V
RUN1, 2
R , R
FB1 FB2
Resistor Between V
and V
FB
60.1
60.4
60.7
kΩ
OUT
Pins for Each Channel
V
PGOOD Voltage Low
I
= 2mA
= 5V
0.1
0.3
2
V
PGL
PGOOD
I
PGOOD Leakage Current
PGOOD Range
V
μA
PGOOD
PGOOD
V
V
Ramping Negative
Ramping Positive
–5
5
–7.5
7.5
–10
10
%
%
ΔV
FB
FB
PGOOD
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.
internal operating temperature range. Note that the maximum ambient
temperature is determined by specific operating conditions in conjunction
with board layout, the rated package thermal resistance and other
environmental factors.
Note 2: The LTM4619E is guaranteed to meet performance specifications
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 LTM4619I is guaranteed to meet specifications over the full
Note 3: The two outputs are tested separately and the same testing
condition is applied to each output.
Note 4: 100% tested at wafer level only.
Note 5: See Output Current Derating curves for different V , V
and T .
A
IN OUT
TYPICAL PERFORMANCE CHARACTERISTICS
(Refer to Figures 18 and 19)
Efficiency vs Load Current with
Efficiency vs Load Current with
12VIN (f = 500kHz for 1.2VOUT and
5VIN (f = 500kHz for 0.8VOUT
,
Efficiency vs Load Current with
24VIN (f = 500kHz for 1.5VOUT
1.2VOUT and 1.5VOUT
)
1.5VOUT
)
)
95
90
85
80
75
70
65
60
55
50
45
95
90
85
80
75
70
65
60
55
95
90
85
80
75
70
65
60
55
5V
3.3V
OUT
OUT
5V
OUT
2.5V
OUT
3.3V
OUT
3.3V
OUT
2.5V
OUT
1.2V
OUT
1.5V
OUT
1.5V
1.2V
OUT
2.5V
OUT
OUT
1.5V
OUT
0.8V
OUT
0
0.5
1
1.5
2
2.5
3
3.5
4
0
0.5
1
1.5
2
2.5
3
3.5
4
0
0.5
1
1.5
2
2.5
3
3.5
4
LOAD CURRENT (A)
LOAD CURRENT (A)
LOAD CURRENT (A)
4619 G03
4619 G01
4619 G02
4619f
4
LTM4619
(Refer to Figures 18 and 19)
TYPICAL PERFORMANCE CHARACTERISTICS
1.2V Output Transient Response
1.5V Output Transient Response
2.5V Output Transient Response
I
I
I
OUT
1A/DIV
OUT
OUT
1A/DIV
1A/DIV
V
V
V
OUT
OUT
OUT
50mV/DIV
50mV/DIV
50mV/DIV
4619 G04
4619 G05
4619 G06
100μs/DIV
100μs/DIV
100μs/DIV
6V 1.2V
AT 2A/μs LOAD STEP
6V 1.5V
AT 2A/μs LOAD STEP
6V 2.5V AT 2A/μs LOAD STEP
IN
OUT
IN
OUT
IN
OUT
f = 780kHz
f = 780kHz
f = 780kHz
C
C
2s 22μF, 6.3V X5R CERAMIC
1s 330μF, 6.3V SANYO POSCAP
C
C
2s 22μF, 6.3V X5R CERAMIC
1s 330μF, 6.3V SANYO POSCAP
C
C
2s 22μF, 6.3V X5R CERAMIC
1s 330μF, 6.3V SANYO POSCAP
OUT
OUT
OUT
OUT
OUT
OUT
3.3V Output Transient Response
Start-Up, IOUT = 0A
Start-Up, IOUT = 4A
I
V
V
OUT
IN
IN
1A/DIV
1V/DIV
1V/DIV
V
OUT
50mV/DIV
I
I
IN
IN
0.5A/DIV
0.5A/DIV
4619 G09
4619 G07
4619 G08
20ms/DIV
100μs/DIV
20ms/DIV
V
I
= 12V, V
= 2.5V,
6V 3.3V
AT 2A/μs LOAD STEP
V
C
= 12V, V
OUT
= 2.5V, I
= 0A
IN
OUT
IN
OUT
IN
OUT
OUT
= 4A RESISTIVE LOAD
f = 780kHz
= 2s 22μF 10V
OUT
OUT
C
= 2s 22μF 10V,
C
C
2s 22μF, 6.3V X5R CERAMIC
1s 330μF, 6.3V SANYO POSCAP
AND 1s 100μF 6.3V CERAMIC CAPs
OUT
OUT
AND 1s 100μF 6.3V CERAMIC CAPs
C
= 0.1μF
SOFTSTART
C
= 0.1μF
USE RUN PIN TO CONTROL START-UP
SOFTSTART
USE RUN PIN TO CONTROL START-UP
Short Circuit, IOUT = 0A
Short Circuit, IOUT = 4A
V
V
OUT
1V/DIV
OUT
1V/DIV
I
IN
0.5A/DIV
I
IN
0.5A/DIV
4619 G10
4619 G11
50μs/DIV
= 2.5V, I
50μs/DIV
V
C
= 12V, V
OUT
= 0A
V
C
= 12V, V
OUT
= 2.5V, I
= 4A
IN
OUT
OUT
IN
OUT
OUT
= 2s 22μF 10V,
= 2s 22μF 10V,
AND 1s 100μF 6.3V CERAMIC CAPs
AND 1s 100μF 6.3V CERAMIC CAPs
4619f
5
LTM4619
PIN FUNCTIONS
V (J1 to J3, J10 to J12, K1 to K4, K9 to K12, L1 to L5,
FREQ/PLLFLTR (J8): Frequency Selection Pin. An internal
lowpass filter is tied to this pin. The frequency can be se-
lected from 250kHz to 780kHz by varying the DC voltage
on this pin from 0V to 2.4V. Leave this pin floating when
external synchronization is used.
IN
L8 to L12, M1 to M12): Power Input Pins. Apply input
voltage between these pins and PGND pins. Recommend
placing input decoupling capacitance directly between V
IN
CC
pins and PGND pins. For V < 5.5, tie V and INTV
IN
IN
together.
TK/SS1, TK/SS2 (K8, K5): Output Voltage Tracking and
Soft-StartPins.Internalsoft-startcurrentsof1.3μAcharge
thesoft-startcapacitors. SeetheApplicationsInformation
section to use the tracking function.
V
, V
(A10 to D10, A11 to D11, A12 to D12, A1 to
OUT1 OUT2
D1, A2 to D2, A3 to D3): Power Output Pins. Apply output
load between these pins and PGND pins. Recommend
placing output decoupling capacitance directly between
these pins and PGND pins.
V
, V
(K7, K6): The negative input of the error
FB1
FB2
amplifier. Internally, this pin is connected to V
with
OUT
PGND (H1, H2, H4, H9, H11, H12, G1 to G12, F1 to
F5, F7 to F12, E1 to E12, D4 to D9, C4 to C9, B4 to B9,
A4 to A9): Power ground pins for both input and output
returns.
a 60.4k precision resistor. Different output voltages can
be programmed with an additional resistor between V
FB
and SGND pins. See the Applications Information section
for details.
INTV (F6): Internal 5V Regulator Output. This pin is for
COMP1, COMP2 (L7, L6): Current Control Threshold and
ErrorAmplifierCompensationPoint.Themodulehasbeen
internally compensated for most I/O ranges.
CC
additional decoupling of the 5V internal regulator.
EXTV (J4): External Power Input to Controller. When
CC
EXTV is higher than 4.7V, the internal 5V regulator is
PGOOD (H5): Output Voltage Power Good Indicator. Open
drain logic output that is pulled to ground when the output
voltage is not within 7.5% of the regulation point.
CC
disabled and external power supplies current to reduce
the power dissipation in the module. This will improve the
efficiency more at high input voltages.
RUN1, RUN2 (J9, J5): Run Control Pins. 0.5μA pull-up
currents on these pins turn on the module if these pins
are floating. Forcing either of these pins below 1.2V will
shutdownthecorrespondingoutputs.Anadditional4.5μA
pull-up current is added to this pin, once the RUN pin rises
above 1.2V. Also, active control or pull-up resistors can
be used to enable the RUN pin. The maximum voltage is
6V on these pins.
SGND(J6, J7, H6, H7):SignalGroundPin. Returnground
path for all analog and low power circuitry. Tie a single
connection to PGND in the application.
MODE/PLLIN(H8):Modeselectionorexternalsynchroniza-
tion pin. Tying this pin high enables pulse-skipping mode.
Tying this pin low enables force continuous operation.
Floating this pin enables Burst Mode operation. A clock
on the pin will force the controller into continuous mode
of operation and synchronize the internal oscillator. The
external clock input high threshold is 1.6V, while the input
low threshold is 1V.
SW1, SW2(H10, H3):SwitchingTestPins. Thesepinsare
provided externally to check the operation frequency.
4619f
6
LTM4619
SIMPLIFIED BLOCK DIAGRAM
V
INTERNAL
FILTER
IN
4.5V TO 26.5V*
+
+
1.5μF
C
C
IN
INTV
CC
M1
M2
PGND
SW1
PGOOD
L1
MODE/PLLIN
V
OUT1
2.5V/4A
EXTV
CC
10μF
V
IN
OUT1
TK/SS1
PGND
C
SS1
R1
R2
RUN1
60.4k
COMP1
V
FB1
R
28k
INTERNAL
COMP
SET1
POWER
CONTROL
R2
R1ꢀR2
¥
´
• V
IN
¦
§
µ
¶
1.5μF
TK/SS2
= UVLO THRESHOLD = 1.22V
M3
M4
PGND
SW2
C
SS2
L2
RUN2
V
OUT2
3.3V/4A
COMP2
+
10μF
C
OUT2
INTERNAL
COMP
PGND
60.4k
FREQ
V
FB2
INTERNAL
FILTER
R
SET2
19.1k
SGND
4619 BD
*USE EXTV FOR V ≤ 5.5V, OR TIE V AND EXTV TOGETHER FOR V ≤ 5.5V
CC
IN
IN
CC
IN
Figure 1. Simplified LTM4619 Block Diagram
TA = 25°C. Use Figure 1 configuration.
CONDITIONS
DECOUPLING REQUIREMENTS
SYMBOL
PARAMETER
MIN
10
TYP
MAX
UNITS
External Input Capacitor Requirement
C
(V = 4.5V to 26.5V, V
= 2.5V, V
= 3.3V)
= 3.3V)
I
= 4A, I = 4A
OUT2
μF
IN
IN
OUT1
OUT2
OUT1
External Output Capacitor Requirement
(V = 4.5V to 26.5V, V = 2.5V, V
C
C
I
I
= 4A
= 4A
200
200
μF
μF
OUT1
OUT2
IN
OUT1
OUT2
OUT1
OUT2
4619f
7
LTM4619
OPERATION
The LTM4619 is a dual-output standalone non-isolated
switching mode DC/DC power supply. It can deliver up to
4A(DCcurrent)foreachoutputwithfewexternalinputand
outputcapacitors.Thismoduleprovidespreciselyregulated
output voltages programmable via external resistors from
0.8VDC to 5.0VDC over 4.5V to 26.5V input voltages. The
typical application schematic is shown in Figure 18.
the open-drain PGOOD output low if the output feedback
voltageexitsa 7.5%windowaroundtheregulationpoint.
The power good pin is disabled during start-up.
Pulling the RUN pin below 1.2V forces the controller into
its shutdown state, by turning off both MOSFETs. The
TK/SSpinisusedforprogrammingtheoutputvoltageramp
and voltage tracking during start-up. See the Applications
Information section.
The LTM4619 has integrated constant frequency current
mode regulators and built-in power MOSFET devices with
fast switching speed. The typical switching frequency is
780kHz. To reduce switching noise, the two outputs are
interleaved with 180° phase internally and it can be syn-
chronized externally using the PLLIN pin.
The LTM4619 is internally compensated to be stable over
all operating conditions. The Linear Technology μModule
Power Design Tool will be provided for transient and
stability analysis. The V pin is used to program the
FB
output voltage with a single external resistor to ground.
Multiphase operation can be easily employed with the
synchronization.
With current mode control and internal feedback loop
compensation, the LTM4619 module has sufficient stabil-
ity margins and good transient performance with a wide
range of output capacitors, even with all ceramic output
capacitors.
High efficiency at light loads can be accomplished with
selectable Burst Mode operation or pulse-skipping mode
using the MODE pin. Efficiency graphs are provided for
light load operations in the Typical Performance Charac-
teristics section.
Currentmodecontrolprovidescycle-by-cyclefastcurrent
limit and current foldback in a short-circuit condition.
Internal overvoltage and undervoltage comparators pull
4619f
8
LTM4619
APPLICATIONS INFORMATION
The typical LTM4619 application circuit is shown in
Figure 18. External component selection is primarily
determined by the maximum load current and output
voltage.
Without considering the inductor current ripple, for each
output, the RMS current of the input capacitor can be
estimated as:
IOUT(MAX)
ICIN(RMS)
=
• D•(1−D)
Output Voltage Programming
η
ThePWMcontrollerhasaninternal0.8Vreferencevoltage.
As shown in the block diagram, a 60.4k internal feedback
In the above equation, η is the estimated efficiency of the
power module. The bulk capacitor can be a switcher-rated
electrolytic aluminum capacitor, polymer capacitor for
bulk input capacitance due to high inductance traces or
leads. One 10μF ceramic input capacitor is typically rated
for 2A of RMS ripple current, so the RMS input current
at the worst case for each output at 4A maximum current
is about 2A. If a low inductance plane is used to power
the device, then two 10μF ceramic capacitors are enough
for both outputs at 4A load and no external input bulk
capacitor is required.
resistor R connects V
to V pin. The output voltage
FB
OUT
FB
will default to 0.8V with no feedback resistor. Adding a
resistor R from V pin to SGND programs the output
SET
FB
voltage:
60.4k +RSET
VOUT = 0.8V •
RSET
Table 1. VFB Resistor Table vs Various Output Voltages
V
OUT
(V)
0.8
1.2
1.5
1.8
2.5
3.3
5
R
(kꢀ)
Open
121
68.1
48.7
28.0
19.1
11.5
SET
Output Capacitors
The LTM4619 is designed for low output voltage ripple
Input Capacitors
noise. The bulk output capacitors defined as C
are
OUT
The LTM4619 module should be connected to a low AC-
impedanceDCsource.Two1.5μFinputceramiccapacitors
areincludedinsidethemodule.Additionalinputcapacitors
are needed if a large load is required up to the 4A level. A
47μF to 100μF surface mount aluminum electrolytic bulk
capacitor can be used for more input bulk capacitance.
This bulk capacitor is only needed if the input source im-
pedance is compromised by long inductive leads, traces
or not enough source capacitance.
chosen with low enough effective series resistance (ESR)
to meet the output voltage ripple and transient require-
ments. C
can be the low ESR tantalum capacitor, the
OUT
lowESRpolymercapacitororceramiccapacitor.Thetypical
output capacitance range for each output is from 47μF to
220μF. Additional output filtering may be required by the
system designer, if further reduction of output ripples or
dynamictransientspikesisrequired.TheLinearTechnology
μModule Power Design Tool will be provided for stability
analysis.Multiphaseoperationwillreduceeffectiveoutput
ripple as a function of the number of phases. Application
Note77discussesthisnoisereductionversusoutputripple
current cancellation, but the output capacitance should be
consideredcarefullyasafunctionofstabilityandtransient
response. The Linear Technology μModule Power Design
Toolcancalculatetheoutputripplereductionasthenumber
of implemented phases increased by N times.
For a buck converter, the switching duty-cycle can be
estimated as:
VOUT
D=
V
IN
4619f
9
LTM4619
APPLICATIONS INFORMATION
Mode Selections and Phase-Locked Loop
Frequency Selection
The LTM4619 can be enabled to enter high efficiency
BurstModeoperation,constant-frequencypulse-skipping
mode, or forced continuous conduction mode. To select
the forced continuous operation, tie the MODE/PLLIN pin
to a DC voltage below 0.8V. To select pulse-skipping mode
The switching frequency of the LTM4619’s controllers can
be selected using the FREQ/PLLFLTR pin. If the MODE/
PLLIN pin is not being driven by an external clock source,
the FREQ/PLLFLTR pin can be set from 0V to 2.4V to pro-
gram the controller’s operating frequency from 250kHz to
of operation, tie the MODE/PLLIN pin to INTV . To select
780kHz using a voltage divider to INTV (see Figure 19).
CC
CC
Burst Mode operation, float the MODE/PLLIN pin.
The typical frequency is 780kHz. If the output is too low
or the minimum on-time is reached, the frequency needs
to decrease to enlarge the turn-on time. Otherwise, a
significant amount of cycle skipping can occur with cor-
respondingly larger current and voltage ripple.
Frequency Synchronization
A phase-lock loop is available on the LTM4619 to synchro-
nizetheinternalclocktoanexternalclocksourceconnected
on the MODE/PLLIN pin. The clock high level needs to be
higher than 1.6V and the clock low level needs to be lower
than 1V. The frequency programming voltage and or the
programming voltage divider must be removed from the
FREQ/PLLFLTR pin when synchronizing to an external
clock. The FREQ/PLLFLTR pin has the required onboard
PLL filter components for clock synchronization. The LTM
will default to forced continuous mode while being clock
synchronized. Channel 1 is synchronized to the rising
edge on the external clock, and channel 2 is 180 degrees
out-of-phase with the external clock.
RefertothefigureofOutputVoltagevsMinimumOn-Time
to choose a proper frequency.
900
800
700
600
500
400
300
200
100
0
0
0.5
1
1.5
2
2.5
FREQ PIN VOLTAGE (V)
4619 F02
Figure 2. Switching Frequency vs FREQ/PLLFLTR Pin Voltage
4619f
10
LTM4619
APPLICATIONS INFORMATION
Soft-Start and Tracking
Output voltage tracking can be programmed externally
using the TK/SS pin. The master channel is divided down
with an external resistor divider that is the same as the
slave channel’s feedback divider to implement coincident
tracking. The LTM4619 uses an accurate 60.4k resistor
internally for the top feedback resistor. Figure 3 shows an
example of coincident tracking. Figure 4 shows the output
voltages with coincident tracking.
The LTM4619 has the ability to either soft-start by itself
with a capacitor or track the output of another channel or
externalsupply.Whenoneparticularchannelisconfigured
to soft-start by itself, a capacitor should be connected to
its TK/SS pin. This channel is in the shutdown state if its
RUN pin voltage is below 1.2V. Its TK/SS pin is actively
pulled to ground in this shutdown state.
R1
R2
⎛
⎝
⎞
Once the RUN pin voltage is above 1.2V, the channel pow-
ers up. A soft-start current of 1.3μA then starts to charge
its soft-start capacitor. Note that soft-start or tracking is
achieved not by limiting the maximum output current of
the controller but by controlling the output ramp voltage
according to the ramp rate on the TK/SS pin. Current
foldback is disabled during this phase to ensure smooth
soft-start or tracking. The soft-start or tracking range is
defined to be the voltage range from 0V to 0.8V on the
TK/SS pin. The total soft-start time can be calculated as:
VSLAVE = 1+
• V
TRACK
⎜
⎟
⎠
V
is the track ramp applied to the slave’s TK/SS2
TRACK
pin. V
has a control range of 0V to 0.8V. When the
TRACK
master’s output is divided down with the same resistor
values used to set the slave’s output, then the slave will
coincident track with the master until it reaches its final
value. The master will continue to its final value from the
slave’s regulation point.
Ratiometric modes of tracking can be achieved by select-
ing different divider resistors values to change the output
tracking ratio. The master output must be greater than the
slave output for the tracking to work. Master and slave
data inputs can be used to implement the correct resistors
values for coincident or ratio tracking.
0.8V •CSS
tSOFT-START
=
1.3µA
V
MODE/PLLIN INTV
IN
CC
5.5V TO
V
V
FREQ/PLLFLTR
IN
28V
C
IN
V
FB1
FB2
R3
19.1k
R4
MASTER OUTPUT
C2
22pF
C3
22pF
COMP1
COMP2
28k
V
V
LTM4619
OUT2
OUT1
3.3V
V
V
OUT2
OUT1
2.5V
SLAVE OUTPUT
C
C
OUT1
TK/SS1
RUN1
TK/SS2
RUN2
OUT2
OUTPUT
VOLTAGE
C1
0.1μF
V
OUT1
PGOOD
EXTV
CC
R1
60.4k
SGND
PGND
4619 F03
R2
28k
4619 F04
TIME
Figure 3. Example of Coincident Tracking
Figure 4. Coincident Tracking
4619f
11
LTM4619
APPLICATIONS INFORMATION
0.60
1-PHASE
2-PHASE
3-PHASE
4-PHASE
6-PHASE
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9
DUTY FACTOR (V /V
)
OUT IN
4619 F05
Figure 5. Normalized Input RMS Ripple Current vs Duty Factor for One to Six Phases
1.00
1-PHASE
2-PHASE
3-PHASE
4-PHASE
6-PHASE
0.95
0.90
0.85
0.80
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9
DUTY CYCLE (V /V
)
OUT IN
4619 F06
Figure 6. Normalized Output Ripple Current vs Duty Cycle, Dlr = VOUT T/L
4619f
12
LTM4619
APPLICATIONS INFORMATION
Multiphase Operation
RUN Pin
Multiphase operation with multiple LTM4619 devices in
parallel will lower the effective input RMS ripple current
as well as the output ripple current due to the interleaving
operation of the regulators. Figure 5 provides a ratio of
input RMS ripple current to DC load current as a function
of duty cycle and the number of paralleled phases. Choose
the corresponding duty factor and the number of phases
to get the correct ripple current value. For example, the
2-phase parallel for one LTM4619 design provides 8A
at 2.5V output from a 12V input. The duty cycle is DC =
2.5V/12V = 0.21. The 2-phase curve has a ratio of ~0.25
for a duty cycle of 0.21. This 0.25 ratio of RMS ripple cur-
rent to a DC load current of 8A equals ~2A of input RMS
ripple current for the external input capacitors.
The RUN pins can be used to enable or sequence the
particular regulator channel. The RUN pins have their
own internal 0.5μA current source to pull up the pin to
1.2V, and then the current increases to 4.5μA above 1.2V.
Careful consideration is needed to assure that board
contamination or residue does not load down the 0.5μA
pull-up current. Otherwise active control to these pins can
be used to activate the regulators. A voltage divider can
be used from V to set an enable point that can be used
IN
as a UVLO feature for the regulator. The resistor divider
needs to be low enough resistance to swamp out the pull-
up current sources and not enable the device when not
attended. See the Simplified Block Diagram.
Power Good
The effective output ripple current is lowered with mul-
tiphase operations as well. Figure 6 provides a ratio of
peak-to-peak output ripple current to the normalized
output ripple current as a function of duty factor and the
number of paralleled phases. Choose the corresponding
duty factor and the number of phases to get the correct
output ripple current ratio value. If a 2-phase operation
ThePGOODpinisconnectedtoanopendrainofaninternal
N-channel MOSFET. The MOSFET turns on and pulls the
PGOOD pin low when either V pin voltage is not within
FB
7.5% of the 0.8V reference voltage. The PGOOD pin is
alsopulledlowwheneitherRUNpinisbelow1.2Vorwhen
the LTM4619 is in the soft-start or tracking phase. When
the V pin voltage is within the 7.5% requirement, the
is chosen at 12V to 2.5V
with a duty factor of 21%,
FB
IN
OUT
MOSFET is turned off and the pin is allowed to be pulled
up by an external resistor to a source of up to 6V. The
PGOOD pin will flag power good immediately when both
then 0.6 is the ratio of the normalized output ripple current
to inductor ripple DIr at the zero duty factor. This leads
to ~1.3A of the effective output ripple current ΔI if the
L
V
pins are within the 7.5% window. However, there is
DIr is at 2.2A. Refer to Application Note 77 for a detailed
explanation of the output ripple current reduction as a
function of paralleled phases.
FB
an internal 17μs power bad mask when either V goes
FB
out of the 7.5% window.
The output voltage ripple has two components that are
related to the amount of bulk capacitance and effective
series resistance (ESR) of the output bulk capacitance.
Therefore, the output voltage ripple can be calculated with
the known effective output ripple current. The equation:
ΔV
≈ ΔI /(8 • f • N • C ) + ESR • ΔI
L OUT L
OUT(P-P)
where f is frequency and N is the number of parallel
phases.
4619f
13
LTM4619
APPLICATIONS INFORMATION
Fault Conditions: Current Limit and Overcurrent
Foldback
INTV and EXTV
CC
CC
The INTV is the internal 5V regulator that powers the
CC
The LTM4619 has a current mode controller, which inher-
ently limits the cycle-by-cycle inductor current not only in
steady-state operation, but also in transient.
LTM4619internalcircuitryanddrivesthepowerMOSFETs.
The input voltage of the LTM4619 must be 6V or above
for the INTV to regulate to the proper 5V level due to
CC
the internal LDO dropout from the input voltage. For ap-
plications that need to operate below 6V input, then the
To further limit current in the event of an overload condi-
tion,theLTM4619providesfoldbackcurrentlimiting.Ifthe
output voltage falls by more than 50%, then the maximum
output current is progressively lowered to one-third of its
fullcurrentlimitvalue.Foldbackcurrentlimitingisdisabled
during the soft-start and tracking up.
input voltage can be connected directly to the EXTV
CC
pin to bypass the LDO dropout concern, or an external
5V supply can be used to power the EXTV pin when
CC
the input voltage is at high end of the supply range to
reduce power dissipation in the module. For example the
dropout voltage for 24V input would be 24V – 5V = 19V.
This 19V headroom then multiplied by the power MOSFET
drive current of ~15mA would equal ~0.3W additional
power dissipation. So utilizing an external 5V supply on
Thermal Considerations and Output Current Derating
Indifferentapplications,theLTM4619operatesinavariety
of thermal environments. The maximum output current is
limited by the environmental thermal condition. Sufficient
cooling should be provided to ensure reliable operation.
When the cooling is limited, proper output current derat-
ing is necessary, considering the ambient temperature,
airflow,input/outputconditions,andtheneedforincreased
reliability.
the EXTV would improve design efficiency and reduce
CC
device temperature rise.
Slope Compensation
The module has already been internally compensated
for all output voltages. The Linear Technology μModule
Power Design Tool will be provided for control loop op-
timization.
Two outputs of LTM4619 are paralleled to get high output
current for derating curve tests. The power loss curves in
Figures 7 and 8 can be used in coordination with the load
current derating curves in Figures 9 to 16 for calculating
Burst Mode Operation and Pulse-Skipping Mode
an approximate θ for the module with various cooling
JA
The LTM4619 regulator can be placed into high efficiency
power saving modes at light load condition to conserve
power. The Burst Mode operation can be selected by float-
ing the MODE/PLLIN pin, and pulse-skipping mode can
methods. Application Note 103 provides a detailed ex-
planation of the analysis for the thermal models and the
derating curves. Tables 2 and 3 provide a summary of the
equivalent θ for the noted conditions. These equivalent
JA
be selected by pulling the MODE/PLLIN pin to INTV .
CC
θ
JA
parameters are correlated to the measured values,
and are improved with airflow. The junction temperature
is maintained at 125°C or below for the derating curves.
Burst Mode operation offers the best efficiency at light
load, but output ripple will be higher and lower frequency
rangesarecapablewhichcaninterferewithsomesystems.
Pulse-skipping mode efficiency is not as good as Burst
Mode operation, but this mode only skips pulses to save
efficiencyandmaintainsaloweroutputrippleandahigher
switchingfrequency.BurstModeoperationandpulse-skip-
ping mode efficiencies can be reviewed in graph supplied
in the Typical Performance Characteristics section.
Safety Considerations
TheLTM4619modulesdonotprovideisolationfromV to
IN
V
OUT
.Thereisnointernalfuse.Ifrequired,aslowblowfuse
with a rating twice the maximum input current needs to be
provided to protect each unit from catastrophic failure.
4619f
14
LTM4619
APPLICATIONS INFORMATION
Table 2. 1.5V Output
DERATING CURVE
Figures 9, 11
Figures 9, 11
Figures 9, 11
Figures 10, 12
Figures 10, 12
Figures 10, 12
V
(V)
POWER LOSS CURVE
Figure 7
AIRFLOW (LFM)
HEATSINK
none
Θ
JA
(°C/W)
IN
6, 12
6, 12
6, 12
6, 12
6, 12
6, 12
0
12.8
9.0
Figure 7
200
400
0
none
Figure 7
none
8.0
Figure 7
BGA Heatsink
BGA Heatsink
BGA Heatsink
11.9
8.4
Figure 7
200
400
Figure 7
7.4
Table 3. 3.3V Output
DERATING CURVE
Figures 13, 15
V
(V)
POWER LOSS CURVE
Figure 8
AIRFLOW (LFM)
HEATSINK
none
Θ
(°C/W)
IN
JA
12, 24
0
13.4
9.6
Figures 13, 15
12, 24
12, 24
12, 24
12, 24
12, 24
Figure 8
200
400
0
none
Figures 13, 15
Figure 8
none
8.5
Figures 14, 16
Figure 8
BGA Heatsink
BGA Heatsink
BGA Heatsink
12.5
8.9
Figures 14, 16
Figure 8
200
400
Figures 14, 16
Figure 8
7.9
HEATSINK MANUFACTURER
PART NUMBER
WEBSITE
www.aavid.com
Aavid Thermalloy
375424B00034G
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
3.0
2.5
2.0
1.5
1.0
0.5
12V LOSS
24V LOSS
6V LOSS
12V LOSS
0
0
0
0
2
4
6
8
2
4
6
8
LOAD CURRENT (A)
LOAD CURRENT (A)
4619 F08
4619 F07
Figure 7. Power Loss at 1.5V Output
Figure 8. Power Loss at 3.3V Output
4619f
15
LTM4619
APPLICATIONS INFORMATION
8
7
6
5
4
3
2
8
7
6
5
4
3
2
1
0
6V TO 1.5V
0LFM
200LFM
400LFM
6V TO 1.5V
0LFM
200LFM
400LFM
IN
OUT
OUT
OUT
IN
OUT
OUT
OUT
1
0
6V TO 1.5V
6V TO 1.5V
IN
IN
6V TO 1.5V
6V TO 1.5V
IN
IN
70 75 80 85 90 95 100 105 110 115
70 75 80 85 90 95 100 105 110 115
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4619 F09
4619 F10
Figure 10. 6VIN to 1.5VOUT
with Heat Sink
Figure 9. 6VIN to 1.5VOUT
without Heat Sink
8
7
6
5
4
3
2
1
0
8
7
6
5
4
3
2
8
7
6
5
4
3
2
12V TO 1.5V
0LFM
200LFM
400LFM
12V TO 1.5V
0LFM
200LFM
400LFM
12V TO 3.3V
0LFM
200LFM
400LFM
IN
OUT
OUT
OUT
IN
OUT
OUT
OUT
IN
OUT
OUT
OUT
1
0
1
0
12V TO 1.5V
12V TO 1.5V
12V TO 3.3V
IN
IN
IN
12V TO 1.5V
12V TO 1.5V
12V TO 3.3V
IN
IN
IN
70 75 80 85 90 95 100 105 110 115
70 75 80 85 90 95 100 105 110 115
60 65 70 75 80 85 90 95 100 105 110
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4619 F11
4619 F12
4619 F13
Figure 13. 12VIN to 3.3VOUT
without Heat Sink
Figure 12. 12VIN to 1.5VOUT
with Heat Sink
Figure 11. 12VIN to 1.5VOUT
without Heat Sink
8
7
6
5
4
3
2
1
0
8
7
6
5
4
3
2
1
0
8
7
6
5
4
3
2
1
0
12V TO 3.3V
0LFM
200LFM
400LFM
24V TO 3.3V
0LFM
200LFM
400LFM
24V TO 3.3V
0LFM
200LFM
400LFM
IN
OUT
OUT
OUT
IN
OUT
OUT
OUT
IN
OUT
OUT
OUT
12V TO 3.3V
24V TO 3.3V
24V TO 3.3V
IN
IN
IN
12V TO 3.3V
24V TO 3.3V
24V TO 3.3V
IN
IN
IN
60 65 70 75 80 85 90 95 100 105 110
40
50
60
70
80
90
100
40
50
60
70
80
90
100
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4619 F14
4619 F15
4619 F16
Figure 14. 12VIN to 3.3VOUT
with Heat Sink
Figure 15. 24VIN to 3.3VOUT
without Heat Sink
Figure 16. 24VIN to 3.3VOUT
with Heat Sink
4619f
16
LTM4619
APPLICATIONS INFORMATION
Layout Checklist/Example
• Tominimizetheviaconductionlossandreducemodule
thermal stress, use multiple vias for interconnections
between top layer and other power layers.
The high integration of LTM4619 makes the PCB board
layoutverysimpleandeasy.However,tooptimizeitselectri-
cal and thermal performance, some layout considerations
are still necessary.
• Do not put vias directly on the pad.
• Use a separated SGND ground copper area for com-
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit.
• UselargePCBcopperareasforhighcurrentpath,includ-
ing V , PGND, V
and V
. It helps to minimize
IN
OUT1
OUT2
the PCB conduction loss and thermal stress.
• Decouple the input and output grounds to lower the
output ripple noise. Refer to Figure 17.
• Place high frequency ceramic input and output capaci-
tors next to the V , PGND and V
pins to minimize
IN
OUT
Figure 17 gives a good example of the recommended
layout.
high frequency noise.
• Place a dedicated power ground layer underneath the
unit.
TOP VIEW
PGND
V
IN
PGND
M
L
C
IN2
C
IN1
K
J
H
G
F
E
D
C
B
A
1
2
3
4
5
6
7
8
9
10
11
12
C
OUT2
C
OUT1
V
OUT2
PGND
V
OUT1
Figure 17. Recommended PCB Layout
4619f
17
LTM4619
TYPICAL APPLICATIONS
MODE/PLLIN INTV
CC
V
IN
V
V
FREQ/PLLFLTR
4.5V TO 26.5V
IN
C
11.5k
19.1k
IN
10μF
V
FB1
FB2
s2
C1
C2
COMP1
COMP2
22pF
22pF
V
V
OUT2
OUT1
5V/4A
V
V
OUT2
OUT1
3.3V/4A
LTM4619
C
C
OUT2
100μF
OUT1
TK/SS1
RUN1
TK/SS2
RUN2
100μF
0.1μF
0.1μF
100k
R1 (OPT*)
INTV
PGOOD
EXTV
V
IN
CC
CC
SGND
PGND
4619 F18
PGOOD
*R1 IS NEEDED FOR 4.5V < V < 5.5V
IN
Figure 18. Typical 4.5V to 26.5V Input, 5V and 3.3V Outputs at 4A Design
4619f
18
LTM4619
TYPICAL APPLICATIONS
EXTERNAL 5V SUPPLY FOR
INPUT VOLTAGE BELOW 5.5V
R1
3.83k
R2
1.21k
MODE/PLLIN INTV EXTV
CC
CC
V
IN
V
V
FREQ/PLLFLTR
IN
4.5V TO
26.5V
C
IN
121k
68.1k
10μF
V
FB2
FB1
s2
C1
C2
COMP1
COMP2
22pF
22pF
V
V
OUT2
OUT1
1.2V/4A
V
V
OUT2
OUT1
1.5V/4A
LTM4619
C
C
OUT2
OUT1
TK/SS1
RUN1
TK/SS2
RUN2
100μF
100μF
s2
s2
0.1μF
0.1μF
100k
INTV
PGOOD
CC
SGND
PGND
4619 F19
PGOOD
Figure 19. Typical 4.5V to 26.5V Input, 1.2V and 1.5V
Outputs at 4A Design with Adjusted Frequency at 500kHz
4619f
19
LTM4619
TYPICAL APPLICATIONS
MODE/PLLIN EXTV
INTV
CC
CC
V
IN
V
FREQ/PLLFLTR
IN
6V TO
26.5V
C
IN
COMP1
COMP2
TK/SS1
TK/SS2
PGOOD
V
V
10μF
FB1
FB2
C1
51pF
R1
5.76k
V
V
LTM4619
OUT1
OUT2
V
OUT2
5V/8A
+
C4
100μF
C5
C3
0.1μF
RUN2
RUN1
330μF
SGND
PGND
4619 F20
Figure 20. Output Paralleled LTM4619 Module for 5V Output at 8A Design
4619f
20
LTM4619
TYPICAL APPLICATIONS
CLOCK SYNC, 0° PHASE
MODE/PLLIN INTV
CC
V
IN
V
IN
FREQ/PLLFLTR
6V TO 26.5V
+
C
10μF
2x
C
IN2
IN1
V
FB1
V
FB2
330μF
R3
11.5k
R4
19.1k
C10
C11
22pF
COMP1
COMP2
22pF
V
OUT2
V
OUT1
LTM4619
V
OUT1
V
OUT2
3.3V/4A
5V/4A
+
+
V
C3
22μF
C4
22μF
OUT1
C2
220μF
C5
220μF
TK/SS1
RUN1
TK/SS2
RUN2
C1
R1
60.4k
0.1μF
PGOOD
EXTV
CC
R2
19.1k
2 PHASE OSCILLATOR
+
SGND
PGND
V
OUT1
OUT2
MOD
ON/OFF
C3
0.1μF
GND
SET
LTC6908-2
R9
143k
CLOCK SYNC, 90° PHASE
MODE/PLLIN INTV
CC
V
IN
FREQ/PLLFLTR
V
V
FB1
FB2
R7
28k
R8
48.7k
C12
22pF
C13
22pF
COMP1
COMP2
V
OUT4
V
OUT3
LTM4619
V
V
1.8V/4A
OUT1
OUT2
2.5V/4A
+
+
V
V
OUT1
C8
22μF
C6
22μF
OUT1
C9
220μF
C7
220μF
TK/SS1
RUN1
TK/SS2
RUN2
R10
60.4k
R5
60.4k
PGOOD
EXTV
CC
R11
28k
R6
48.7k
SGND
PGND
4619 F21
Figure 21. 4-Phase, Four Outputs (5V, 3.3V, 2.5V and 1.8V) with Tracking
4619f
21
LTM4619
PACKAGE DESCRIPTION
Pin Assignment Table 4
(Arranged by Pin Function)
PIN NAME
PIN NAME
PIN NAME
PIN NAME
A1
V
V
V
GND
GND
GND
GND
GND
GND
D1
V
OUT2
OUT2
GND
GND
GND
GND
GND
GND
G1
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
K1
V
V
V
V
OUT2
OUT2
OUT2
OUT2
IN
IN
IN
IN
A2
D2
V
V
G2
K2
A3
D3
G3
K3
A4
D4
G4
K4
A5
D5
G5
K5
TK2
A6
D6
G6
K6
V
V
FB2
FB1
A7
D7
G7
K7
A8
D8
G8
K8
TK1
A9
D9
G9
K9
V
IN
V
IN
V
IN
V
IN
A10
A11
A12
V
V
V
D10
D11
D12
V
V
V
G10
G11
G12
K10
K11
K12
OUT1
OUT1
OUT1
OUT1
OUT1
OUT1
B1
V
V
V
GND
GND
GND
GND
GND
GND
E1
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
H1
GND
L1
V
V
V
V
V
OUT2
OUT2
OUT2
IN
IN
IN
IN
IN
B2
E2
H2
GND
L2
B3
E3
H3
SW2
GND
L3
B4
E4
H4
L4
B5
E5
H5
PGOOD
SGND
SGND
MODE/PLLIN
GND
L5
B6
E6
H6
L6
COMP2
COMP1
B7
E7
H7
L7
B8
E8
H8
L8
V
V
V
V
V
IN
IN
IN
IN
IN
B9
E9
H9
L9
B10
B11
B12
V
V
V
E10
E11
E12
H10
H11
H12
SW1
L10
L11
L12
OUT1
OUT1
OUT1
GND
GND
C1
V
V
V
GND
GND
GND
GND
GND
GND
F1
GND
GND
GND
GND
GND
INTV
GND
GND
GND
GND
GND
GND
J1
V
V
V
M1
M2
M3
M4
M5
M6
M7
M8
M9
M10
M11
M12
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
V
IN
OUT2
OUT2
OUT2
IN
IN
IN
C2
F2
J2
C3
F3
J3
C4
F4
J4
EXTV
CC
C5
F5
J5
RUN2
C6
F6
J6
SGND
CC
C7
F7
J7
SGND
C8
F8
J8
FREQ/PLLFLTR
RUN1
C9
F9
J9
C10
C11
C12
V
V
V
F10
F11
F12
J10
J11
J12
V
V
V
OUT1
OUT1
OUT1
IN
IN
IN
4619f
22
LTM4619
PACKAGE DESCRIPTION
LGA Package
144-Lead (15mm × 15mm × 2.82mm)
(Reference LTC DWG # 05-08-1816)
Z
b b b
Z
6 . 9 8 5 0
5 . 7 1 5 0
4 . 4 4 5 0
3 . 1 7 5 0
1 . 9 0 5 0
0 . 6 3 5 0
0 . 0 0 0 0
0 . 6 3 5 0
1 . 9 0 5 0
3 . 1 7 5 0
4 . 4 4 5 0
5 . 7 1 5 0
6 . 9 8 5 0
4619f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
23
LTM4619
PACKAGE PHOTOGRAPH
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTM4614
Dual 4A Low V DC/DC μModule
2.375V ≤ V ≤ 5.5V; 0.8V ≤ V
≤ 5V; 15mm × 15mm × 2.8mm LGA
OUT
IN
IN
LTM4615
Triple Low V DC/DC μModule
Two 4A Outputs and One 1.5A; 15mm × 15mm × 2.8mm LGA
2.7V ≤ V ≤ 5.5V; 0.6V ≤ V ≤ 5V; 15mm × 15mm × 2.8mm LGA
IN
LTM4616
Dual 8A Low V DC/DC μModule
IN
IN
OUT
4619f
LT 0709 • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
24
●
●
© LINEAR TECHNOLOGY CORPORATION 2009
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
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