LTM4609 Datasheet

Linear Technology/Analog Devices

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Datasheet

LTM4609
1
4609ff
For more information www.linear.com/LTM4609
Features
applications
Description
36VIN, 34VOUT High Efficiency
Buck-Boost DC/DC
µModule Regulator
The LT M
®
4609 is a high efficiency switching mode buck-
boost power supply. Included in the package are the
switching controller, power FETs and support components.
Operating over an input voltage range of 4.5V to 36V, the
LTM4609 supports an output voltage range of 0.8V to
34V, set by a resistor. This high efficiency design delivers
up to 4A continuous current in boost mode (10A in buck
mode). Only the inductor, sense resistor, bulk input and
output capacitors are needed to finish the design.
The low profile package enables utilization of unused space
on the bottom of PC boards for high density point of load
regulation. The high switching frequency and current
mode architecture enable a very fast transient response
to line and load changes without sacrificing stability. The
LTM4609 can be frequency synchronized with an external
clock to reduce undesirable frequency harmonics.
Fault protection features include overvoltage and foldback
current protection. The DC/DC µModule
®
regulator is of-
fered in small 15mm × 15mm × 2.82mm LGA and 15mm
× 15mm × 3.42mm BGA packages. The LTM4609 is avail-
able with SnPb (BGA) or RoHS compliant terminal finish.
L, LT, LTC, LTM, Linear Technology, the Linear logo, µModule, Burst Mode and PolyPhase are
registered trademarks and No RSENSE is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
30V/2A Buck-Boost DC/DC µModule Regulator with 6.5V to 36V Input
n Single Inductor Architecture Allows VIN Above,
Below or Equal to VOUT
n Wide VIN Range: 4.5V to 36V
n Wide VOUT Range: 0.8V to 34V
n IOUT: 4A DC (10A DC in Buck Mode)
n Up to 98% Efficiency
n Current Mode Control
n Power Good Output Signal
n Phase-Lockable Fixed Frequency: 200kHz to 400kHz
n Ultrafast Transient Response
n Current Foldback Protection
n Output Overvoltage Protection
n Small Surface Mount Footprint, Low Profile
(15mm × 15mm × 2.82mm) LGA and
(15mm × 15mm × 3.42mm) BGA Packages
n SnPb (BGA) or RoHS Compliant (LGA and BGA)
Finish
n Telecom, Servers and Networking Equipment
n Industrial and Automotive Equipment
n High Power Battery-Operated Devices
Efficiency and Power Loss
vs Input Voltage
typical application
VOUT
FCB
RUN
SW1
SW2
RSENSE
SENSE
SS
VFB
SGND
PLLIN
LTM4609 5.6µH
2.74k
10µF
50V
330µF
50V
4609 TA01a
VOUT
30V
2A
CLOCK SYNC
VIN
PGND
VIN
6.5V TO 36V
0.1µF
10µF
50V +
ON/OFF
SENSE+
R2
15mΩ
×2
8
99
98
97
96
95
94
93
91
92
6
5
4
3
2
1
0
20 32
4609 TA01b
12 16 24 28 36
VIN (V)
EFFICIENCY (%)
POWER LOSS (W)
EFFICIENCY
POWER LOSS
LTM4609
2
4609ff
For more information www.linear.com/LTM4609
pin conFiguration
absolute MaxiMuM ratings
VIN ............................................................. 0.3V to 36V
VOUT ............................................................. 0.8V to 36V
INTVCC, EXTVCC, RUN, SS, PGOOD .............. 0.3V to 7V
SW1, SW2 (Note 7) ...................................... 5V to 36V
VFB ............................................................ 0.3V to 2.4V
COMP........................................................... 0.3V to 2V
FCB, STBYMD ....................................... 0.3V to INTVCC
PLLIN ........................................................ 0.3V to 5.5V
(Note 1)
LGA PACKAGE
141-LEAD (15mm × 15mm × 2.82mm)
SW2
(BANK 2)
VIN
(BANK 1)
RSENSE
(BANK 3)
COMP
PLLFLTR
PLLIN
SW1
(BANK 4)
VOUT
(BANK 5)
INTVCC
EXTVCC
PGOOD
VFB
PGND
(BANK 6)
SENSE+STBYMD
TOP VIEW
1 2 3 4 5 6 7 8 109 11 12
L
K
J
H
G
F
E
D
C
B
M
A
SSSENSESGND RUN FCB
TJMAX = 125°C, θJA = 11.4°C/W, θJCtop = 15°C/W, θJCbottom = 4°C/W, WEIGHT = 1.5g
BGA PACKAGE
141-LEAD (15mm × 15mm × 3.42mm)
SW2
(BANK 2)
VIN
(BANK 1)
RSENSE
(BANK 3)
COMP
PLLFLTR
PLLIN
SW1
(BANK 4)
VOUT
(BANK 5)
INTVCC
EXTVCC
PGOOD
VFB
PGND
(BANK 6)
SENSE+STBYMD
TOP VIEW
1 2 3 4 5 6 7 8 109 11 12
L
K
J
H
G
F
E
D
C
B
M
A
SSSENSESGND RUN FCB
TJMAX = 125°C, θJA = 11.4°C/W, θJCtop = 15°C/W, θJCbottom = 4°C/W, WEIGHT = 1.7g
(See Table 6 Pin Assignment)
orDer inForMation
PLLFLTR .................................................... 0.3V to 2.7V
INTVCC ................................................................ 40mA
Operating Temperature Range (Note 2)
E- and I-grades ....................................40°C to 85°C
MP-grade ........................................... –55°C to 125°C
Junction Temperature ........................................... 125°C
Storage Temperature Range ...................55°C to 125°C
Solder Temperature (Note 3) ................................. 245°C
PART NUMBER PAD OR BALL FINISH PART MARKING* PACKAGE
TYPE
MSL
RATING
TEMPERATURE RANGE
(Note 2)
DEVICE FINISH CODE
LTM4609EV#PBF Au (RoHS) LTM4609V e4 LGA 3 –40°C to 85°C
LTM4609IV#PBF Au (RoHS) LTM4609V e4 LGA 3 –40°C to 85°C
LTM4609MPV#PBF Au (RoHS) LTM4609V e4 LGA 3 –55°C to 125°C
LTM4609EY#PBF SAC305 (RoHS) LTM4609Y e1 BGA 3 –40°C to 85°C
LTM4609IY#PBF SAC305 (RoHS) LTM4609Y e1 BGA 3 –40°C to 85°C
LTM4609IY SnPb (63/37) LTM4609Y e0 BGA 3 –40°C to 85°C
LTM4609MPY #PBF SAC305 (RoHS) LTM4609Y e1 BGA 3 –55°C to 125°C
LTM4609MPY SnPb (63/37) LTM4609Y e0 BGA 3 –55°C to 125°C
Consult Marketing for parts specified with wider operating temperature
ranges. *Device temperature grade is indicated by a label on the shipping
container. Pad or ball finish code is per IPC/JEDEC J-STD-609.
• Pb-free and Non-Pb-free Part Markings:
www.linear.com/leadfree
• Recommended LGA and BGA PCB Assembly and Manufacturing
Procedures:
www.linear.com/umodule/pcbassembly
• LGA and BGA Package and Tray Drawings:
www.linear.com/packaging
LTM4609
3
4609ff
For more information www.linear.com/LTM4609
The l denotes the specifications which apply over the specified operating
temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Specifications
VIN(DC) Input DC Voltage l4.5 36 V
VIN(UVLO) Undervoltage Lockout Threshold VIN Falling (–40°C to 85°C)
VIN Falling (–55°C to 125°C)
l
l
3.4
3.4
4
4.5
V
V
IQ(VIN) Input Supply Bias Current
Normal
Standby
Shutdown Supply Current
VRUN = 0V, VSTBYMD > 2V
VRUN = 0V, VSTBYMD = Open
2.8
1.6
35
60
mA
mA
µA
Output Specifications
IOUTDC Output Continuous Current Range
(Note 3)
VIN = 32V, VOUT = 12V
VIN = 6V, VOUT = 12V
10
4
A
A
ΔVFB/VFB(NOM) Line Regulation Accuracy VIN = 4.5V to 36V, VCOMP = 1.2V (Note 4) 0.002 0.02 %/V
ΔVFB/VFB(LOAD) Load Regulation Accuracy VCOMP = 1.2V to 0.7V
VCOMP = 1.2V to 1.8V (Note 4)
l
l
0.15
0.15
0.5
0.5
%
%
Switch Section (Note 5)
M1 trTurn-On Time Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
50 ns
M1 tfTurn-Off Time Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
40 ns
M3 trTurn-On Time Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
25 ns
M3 tfTurn-Off Time Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
20 ns
M2, M4 trTurn-On Time Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
20 ns
M2, M4 tfTurn-Off Time Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
20 ns
t1d M1 Off to M2 On Delay Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
50 ns
t2d M2 Off to M1 On Delay Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
50 ns
t3d M3 Off to M4 On Delay Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
50 ns
t4d M4 Off to M3 On Delay Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
50 ns
Mode Transition 1 M2 Off to M4 On Delay Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
220 ns
Mode Transition 2 M4 Off to M2 On Delay Drain to Source Voltage VDS = 12V,
Bias Current ISW = 10mA
220 ns
M1 RDS(ON) Static Drain-to-Source
On-Resistance
Bias Current ISW = 3A 10
M2 RDS(ON) Static Drain-to-Source
On-Resistance
Bias Current ISW = 3A 14 20
M3 RDS(ON) Static Drain-to-Source
On-Resistance
Bias Current ISW = 3A 14 20
M4 RDS(ON) Static Drain-to-Source
On-Resistance
Bias Current ISW = 3A 14 20
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLFLTR = 1.2V 260 300 330 kHz
fLOW Lowest Frequency VPLLFLTR = 0V 170 200 220 kHz
electrical characteristics
LTM4609
4
4609ff
For more information www.linear.com/LTM4609
electrical characteristics
The l denotes the specifications which apply over the specified operating
temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
fHIGH Highest Frequency VPLLFLTR = 2.4V 340 400 440 kHz
RPLLIN PLLIN Input Resistance 50
IPLLFLTR Phase Detector Output Current fPLLIN < fOSC
fPLLIN > fOSC
–15
15
µA
µA
Control Section
VFB Feedback Reference Voltage VCOMP = 1.2V(–40°C to 85°C)
VCOMP = 1.2V (–55°C to 125°C)
l
l
0.792
0.785
0.8
0.8
0.808
0.815
V
V
VRUN RUN Pin ON/OFF Threshold 1 1.6 2.2 V
ISS Soft-Start Charging Current VRUN = 2.2V –1.7 –1 µA
VSTBYMD(START) Start-Up Threshold VSTBYMD Rising 0.4 0.7 V
VSTBYMD(KA) Keep-Active Power On Threshold VSTBYMD Rising, VRUN = 0V 1.25 V
VFCB Forced Continuous Threshold 0.76 0.8 0.84 V
IFCB Forced Continuous Pin Current VFCB = 0.85V –0.3 –0.2 –0.1 µA
VBURST Burst Inhibit (Constant Frequency)
Threshold
Measured at FCB Pin 5.3 5.5 V
DF(BOOST, MAX) Maximum Duty Factor % Switch M4 On 99 %
DF(BUCK, MAX) Maximum Duty Factor % Switch M1 On 99 %
tON(MIN, BUCK) Minimum On-Time for Synchronous
Switch in Buck Operation
Switch M1 (Note 6) 200 250 ns
RFBHI Resistor Between VOUT and VFB Pins 99.5 100 100.5
Internal VCC Regulator
INTVCC Internal VCC Voltage VIN = 12V, VEXTVCC = 5V
VIN = 7V, VEXTVCC = 5V
l
l
5.7
5.56
6
6
6.3
6.35
V
V
ΔVLDO/VLDO Internal VCC Load Regulation ICC = 0mA to 20mA, VEXTVCC = 5V 0.3 2 %
VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, VEXTVCC Rising l5.4 5.6 V
ΔVEXTVCC(HYS) EXTVCC Switchover Hysteresis 300 mV
ΔVEXTVCC EXTVCC Switch Drop Voltage ICC = 20mA, VEXTVCC = 6V 60 150 mV
Current Sensing Section
VSENSE(MAX) Maximum Current Sense Threshold Boost Mode
Buck Mode
l
l
–95
160
–130
190
–150
mV
mV
VSENSE(MIN, BUCK) Minimum Current Sense Threshold Discontinuous Mode –6 mV
ISENSE Sense Pins Total Source Current VSENSE = VSENSE+ = 0V –380 µA
PGOOD
ΔVFBH PGOOD Upper Threshold VFB Rising 5.5 7.5 10 %
ΔVFBL PGOOD Lower Threshold VFB Falling 5.5 –7.5 –10 %
ΔVFB(HYS) PGOOD Hysteresis VFB Returning 2.5 %
VPGL PGOOD Low Voltage IPGOOD = 2mA 0.2 0.3 V
IPGOOD PGOOD Leakage Current VPGOOD = 5V 1 µA
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 2: The LTM4609 is tested under pulsed load conditions such that
TJ ≈ TA. The LTM4609E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTM4609I is guaranteed over
the –40°C to 85°C operating temperature range. The LTM4609MP is
guaranteed and tested over the –55°C to 125°C operating temperature
range. For output current derating at high temperature, please refer to
Thermal Considerations and Output Current Derating discussion.
Note 3: See output current derating curves for different VIN, VOUT, and TA.
Note 4: The LTM4609 is tested in a feedback loop that servos VCOMP to a
specified voltage and measures the resultant VFB.
Note 5: Turn-on and turn-off time are measured using 10% and 90%
levels. Transition delay time is measured using 50% levels.
Note 6: 100% test at wafer level only.
Note 7: Absolute Maximum Rating of –5V on SW1 and SW2 is under
transient condition only.
LTM4609
5
4609ff
For more information www.linear.com/LTM4609
typical perForMance characteristics
Efficiency vs Load Current
6VIN to 12VOUT
Efficiency vs Load Current
12VIN to 12VOUT
Efficiency vs Load Current
32VIN to 12VOUT
Efficiency vs Load Current
3.3µH Inductor
Transient Response from
6VIN to 12VOUT
Transient Response from
12VIN to 12VOUT
(Refer to Figure 18)
Efficiency vs Load Current
5.6µH Inductor
Efficiency vs Load Current
8µH Inductor
Efficiency vs Load Current
3.3µH Inductor
LOAD CURRENT (A)
0.01
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
10
0
0.1 1 10
4609 G01
BURST
DCM
CCM
LOAD CURRENT (A)
0.01
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
10
0
0.1 1 10
4609 G02
BURST
DCM
CCM
LOAD CURRENT (A)
0.01
EFFICIENCY (%)
0.1 1 10010
4609 G03
0
20
30
40
50
60
70
80
90
100
10
SKIP CYCLE
DCM
CCM
0
85
321 45678
4609 G04
9 10
EFFICIENCY (%)
LOAD CURRENT (A)
70
75
80
90
100
95
12VIN TO 5VOUT
24VIN TO 5VOUT
32VIN TO 5VOUT
LOAD CURRENT (A)
0
90
EFFICIENCY (%)
91
93
94
95
100
97
21 3 4 5
4609 G05
92
98
99
96
678
28VIN to 20VOUT
32VIN to 20VOUT
36VIN to 20VOUT
LOAD CURRENT (A)
0
93
EFFICIENCY (%)
94
95
100
97
123
4609 G06
98
99
96
54 6
30VIN to 30VOUT
32VIN to 30VOUT
36VIN to 30VOUT
LOAD CURRENT (A)
0
70
EFFICIENCY (%)
75
85
90
95
100
0.5 1 1.5
4609 G07
80
2.52 3
5VIN to 16VOUT
5VIN to 24VOUT
5VIN to 30VOUT
LOAD STEP: 0A TO 3A AT CCM
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 15mΩ SENSING RESISTORS
200µs/DIV 4609 G08
IOUT
2A/DIV
VOUT
200mV/DIV
LOAD STEP: 0A TO 3A AT CCM
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 15mΩ SENSING RESISTORS
200µs/DIV 4609 G09
IOUT
2A/DIV
VOUT
200mV/DIV
LTM4609
6
4609ff
For more information www.linear.com/LTM4609
typical perForMance characteristics
Start-Up with 6VIN to 12VOUT at
IOUT = 4A
Start-Up with 32VIN to 12VOUT at
IOUT = 5A
Short Circuit with 6VIN to 12VOUT
at IOUT = 4A
Short Circuit with 32VIN to 12VOUT
at IOUT = 5A
Transient Response from
32VIN to 12VOUT
Short Circuit with 12VIN to 34VOUT
at IOUT = 2A
LOAD STEP: 0A TO 5A AT CCM
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 12mΩ SENSING RESISTORS
200µs/DIV
VOUT
100mV/DIV
IOUT
2A/DIV
4609 G10
0.1µF SOFT-START CAP
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 12mΩ SENSING RESISTORS
50ms/DIV
VOUT
10V/DIV
IIN
5A/DIV
IL
5A/DIV
4609 G11
0.1µF SOFT-START CAP
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 12mΩ SENSING RESISTORS
10ms/DIV
VOUT
10V/DIV
IIN
2A/DIV
IL
5A/DIV
4609 G12
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 12mΩ SENSING RESISTORS
50µs/DIV 4609 G13
IIN
5A/DIV
VOUT
5V/DIV
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 12mΩ SENSING RESISTORS
50µs/DIV 4609 G14
VOUT
5V/DIV
IIN
2A/DIV
OUTPUT CAPS: 2x 10µF 50V CERAMIC CAPS AND
2x 47µF 50V ELECTROLYTIC CAPS
2x 15mΩ SENSING RESISTORS
20µs/DIV 4607 G15
IIN
5A/DIV
VOUT
10V/DIV
LTM4609
7
4609ff
For more information www.linear.com/LTM4609
pin Functions
VIN (Bank 1): Power Input Pins. Apply input voltage be-
tween these pins and PGND pins. Recommend placing
input decoupling capacitance directly between VIN pins
and PGND pins.
VOUT (Bank 5): Power Output Pins. Apply output load
between these pins and PGND pins. Recommend placing
output decoupling capacitance directly between these pins
and PGND pins.
PGND (Bank 6): Power Ground Pins for Both Input and
Output Returns.
SW1, SW2 (Bank 4, Bank 2): Switch Nodes. The power
inductor is connected between SW1 and SW2.
RSENSE (Bank 3): Sensing Resistor Pin. The sensing resis-
tor is connected from this pin to PGND.
SENSE+ (Pin A4): Positive Input to the Current Sense and
Reverse Current Detect Comparators.
SENSE (Pin A5): Negative Input to the Current Sense and
Reverse Current Detect Comparators.
EXTVCC (Pin F6): External VCC Input. When EXTVCC exceeds
5.7V, an internal switch connects this pin to INTVCC and
shuts down the internal regulator so that the controller and
gate drive power is drawn from EXTVCC. Do not exceed
7V at this pin and ensure that EXTVCC < VIN
INTVCC (Pin F5): Internal 6V Regulator Output. This pin
is for additional decoupling of the 6V internal regulator.
Do not source more than 40mA from INTVCC.
PLLIN (Pin B9): External Clock Synchronization Input
to the Phase Detector. This pin is internally terminated
to SGND with a 50k resistor. The phase-locked loop will
force the rising bottom gate signal of the controller to be
synchronized with the rising edge of PLLIN signal.
PLLFLTR (Pin B8): The lowpass filter of the phase-locked
loop is tied to this pin. This pin can also be used to set the
frequency of the internal oscillator with an AC or DC volt-
age. See the Applications Information section for details.
SS (Pin A6): Soft-Start Pin. Soft-start reduces the input
surge current from the power source by gradually increas-
ing the controllers current limit.
STBYMD (Pin A10): LDO Control Pin. Determines whether
the internal LDO remains active when the controller is shut
down. See Operations section for details. If the STBYMD
pin is pulled to ground, the SS pin is internally pulled to
ground to disable start-up and thereby providing a single
control pin for turning off the controller. An internal de-
coupling capacitor is tied to this pin.
VFB (Pin B6): The Negative Input of the Error Amplifier.
Internally, this pin is connected to VOUT with a 100k preci-
sion resistor. Different output voltages can be programmed
with an additional resistor between VFB and SGND pins.
See the Applications Information section.
FCB (Pin A9): Forced Continuous Control Input. The voltage
applied to this pin sets the operating mode of the module.
When the applied voltage is less than 0.8V, the forced
continuous current mode is active in boost operation and
the skip cycle mode is active in buck operation. When the
pin is tied to INTVCC, the constant frequency discontinuous
current mode is active in buck or boost operation. See the
Applications Information section.
SGND (Pin A7): Signal Ground Pin. This pin connects to
PGND at output capacitor point.
COMP (Pin B7): Current Control Threshold and Error
Amplifier Compensation Point. The current comparator
threshold increases with this control voltage. The voltage
ranges from 0V to 2.4V.
PGOOD (Pin B5): 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.
RUN (Pin A8): Run Control Pin. A voltage below 1.6V will
turn off the module. There is a 100k resistor between the
RUN pin and SGND in the module. Do not apply more than
6V to this pin. See the Applications Information section.
LTM4609
8
4609ff
For more information www.linear.com/LTM4609
Decoupling requireMents
siMpliFieD block DiagraM
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
CIN External Input Capacitor Requirement
(VIN = 4.5V to 36V, VOUT = 12V)
IOUT = 4A 10 µF
COUT External Output Capacitor Requirement
(VIN = 4.5V to 36V, VOUT = 12V)
IOUT = 4A 200 300 µF
TA = 25°C. Use Figure 1 configuration.
EXTVCC
INTVCC
PGOOD
PLLIN
RUN
ON/OFF
STBYMD
M1
4609 BD
SW2
4.5V TO 36V
SW1
L
VIN
CIN
CONTROLLER
C1
100k
0.1µF
FCB
SGND
TO PGND PLANE AS
SHOWN IN FIGURE 15
1000pF
SS
SS
0.1µF
M2
COMP
M3
12V
4A
VFB
RSENSE
VOUT
COUT
CO1
M4
100k RFB
7.15k
RSENSE
INT
COMP
PLLFLTR
INT
FILTER
INT
FILTER
PGND
SENSE
SENSE+
Figure 1. Simplified LTM4609 Block Diagram
LTM4609
9
4609ff
For more information www.linear.com/LTM4609
operation
Power Module Description
The LTM4609 is a non-isolated buck-boost DC/DC power
supply. It can deliver a wide range output voltage from 0.8V
to 34V over a wide input range from 4.5V to 36V, by only
adding the sensing resistor, inductor and some external
input and output capacitors. It provides precisely regulated
output voltage programmable via one external resistor.
The typical application schematic is shown in Figure 18.
The LTM4609 has an integrated current mode buck-boost
controller, ultralow RDS(ON) FETs with fast switching speed
and integrated Schottky diodes. With current mode control
and internal feedback loop compensation, the LTM4609
module has sufficient stability margins and good transient
performance under a wide range of operating conditions
and with a wide range of output capacitors. The operating
frequency of the LTM4609 can be adjusted from 200kHz
to 400kHz by setting the voltage on the PLLFLTR pin.
Alternatively, its frequency can be synchronized by the
input clock signal from the PLLIN pin. The typical switch-
ing frequency is 400kHz.
The Burst Mode
®
and skip-cycle mode operations can be
enabled at light loads to improve efficiency, while the forced
continuous mode and discontinuous mode operations are
used for constant frequency applications. Foldback current
limiting is activated in an overcurrent condition as VFB
drops. Internal overvoltage and undervoltage compara-
tors pull the open-drain PGOOD output low if the output
feedback voltage exits the ±7.5% window around the
regulation point. Pulling the RUN pin below 1.6V forces
the controller into its shutdown state.
If an external bias supply is applied on the EXTVCC pin, then
an efficiency improvement will occur due to the reduced
power loss in the internal linear regulator. This is especially
true at the higher end of the input voltage range.
applications inForMation
The typical LTM4609 application circuit is shown in Fig-
ure 18. External component selection is primarily deter-
mined by the maximum load current and output voltage.
Refer to Table 3 for specific external capacitor requirements
for a particular application.
Output Voltage Programming
The PWM controller has an internal 0.8V reference voltage.
As shown in the Block Diagram, a 100k internal feedback
resistor connects VOUT and VFB pins together. Adding a
resistor RFB from the VFB pin to the SGND pin programs
the output voltage:
VOUT = 0.8V
FB
R
Table 1. RFB Resistor (0.5%) vs Output Voltage
VOUT 0.8V 1.5V 2.5V 3.3V 5V 6V 8V 9V
RFB Open 115k 47.5k 32.4k 19.1k 15.4k 11k 9.76k
VOUT 10V 12V 15V 16V 20V 24V 30V 34V
RFB 8.66k 7.15k 5.62k 5.23k 4.12k 3.4k 2.74k 2.37k
Operation Frequency Selection
The LTM4609 uses current mode control architecture at
constant switching frequency, which is determined by the
internal oscillators capacitor. This internal capacitor is
charged by a fixed current plus an additional current that
is proportional to the voltage applied to the PLLFLTR pin.
The PLLFLTR pin can be grounded to lower the frequency
to 200kHz or tied to 2.4V to yield approximately 400kHz.
When PLLFLTR is left open, the PLLFLTR pin goes low,
forcing the oscillator to its minimum frequency.
A graph for the voltage applied to the PLLFLTR pin vs
frequency is given in Figure 2. As the operating frequency
increases, the gate charge losses will be higher, thus the
efficiency is lower. The maximum switching frequency is
approximately 400kHz.
FREQUENCY SYNCHRONIZATION
The LTM4609 can also be synchronized to an external
source via the PLLIN pin instead of adjusting the voltage
on the PLLFLTR pin directly. The power module has a
LTM4609
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phase-locked loop comprised of an internal voltage con-
trolled oscillator and a phase detector. This allows turning
on the internal top MOSFET for locking to the rising edge of
the external clock. A pulse detection circuit is used to detect
a clock on the PLLIN pin to turn on the phase-locked loop.
The input pulse width of the clock has to be at least 400ns,
and 2V in amplitude. The synchronized frequency ranges
from 200kHz to 400kHz, corresponding to a DC voltage
input from 0V to 2.4V at PLLFLTR. During the start-up of
the regulator, the phase-locked loop function is disabled.
applications inForMation
Figure 2. Frequency vs PLLFLTR Pin Voltage
Low Current Operation
To improve efficiency at low output current operation,
LTM4609 provides three modes for both buck and boost
operations by accepting a logic input on the FCB pin. Table
2 shows the different operation modes.
Table 2. Different Operating Modes (VINTVCC = 6V)
FCB PIN BUCK BOOST
0V to 0.75V Force Continuous Mode Force Continuous Mode
0.85V to
VINTVCC – 1V
Skip-Cycle Mode Burst Mode Operation
>5.3V DCM with Constant Freq DCM with Constant Freq
When the FCB pin voltage is lower than 0.8V, the controller
behaves as a continuous, PWM current mode synchronous
switching regulator. When the FCB pin voltage is below
VINTVCC – 1V, but greater than 0.85V, where VINTVCC is 6V,
the controller enters Burst Mode operation in boost opera-
tion or enters skip-cycle mode in buck operation. During
boost operation, Burst Mode operation is activated if the
load current is lower than the preset minimum output
current level. The MOSFETs will turn on for several cycles,
followed by a variable “sleep” interval depending upon the
load current. During buck operation, skip-cycle mode sets
a minimum positive inductor current level. In this mode,
some cycles will be skipped when the output load current
drops below 1% of the maximum designed load in order
to maintain the output voltage.
When the FCB pin voltage is tied to the INTVCC pin, the
controller enters constant frequency discontinuous current
mode (DCM). For boost operation, if the output voltage is
high enough, the controller can enter the continuous current
buck mode for one cycle to discharge inductor current.
In the following cycle, the controller will resume DCM
boost operation. For buck operation, constant frequency
discontinuous current mode is turned on if the preset
minimum negative inductor current level is reached. At
very light loads, this constant frequency operation is not
as efficient as Burst Mode operation or skip-cycle, but
does provide low noise, constant frequency operation.
Input Capacitors
In boost mode, since the input current is continuous, only
minimum input capacitors are required. However, the input
current is discontinuous in buck mode. So the selection
of input capacitor CIN is driven by the need of filtering the
input square wave current.
For a buck converter, the switching duty-cycle can be
estimated as:
D=
V
OUT
V
IN
Without considering the inductor current ripple, the RMS
current of the input capacitor can be estimated as:
ICIN(RMS) =
I
OUT(MAX)
ηD(1-D)
In the above equation, η is the estimated efficiency of the
power module. CIN can be a switcher-rated electrolytic
aluminum capacitor, OS-CON capacitor or high volume
ceramic capacitors. Note the capacitor ripple current
ratings are often based on temperature and hours of life.
PLLFLTR PIN VOLTAGE (V)
0 0.5
OPERATING FREQUENCY (kHz)
2.0
450
400
350
300
250
200
150
100
50
0
4609 F02
1.0 1.5 2.5
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applications inForMation
This makes it advisable to properly derate the input capaci-
tor, or choose a capacitor rated at a higher temperature
than required. Always contact the capacitor manufacturer
for derating requirements.
Output Capacitors
In boost mode, the discontinuous current shifts from the
input to the output, so the output capacitor COUT must be
capable of reducing the output voltage ripple.
For boost and buck modes, the steady ripple due to charg-
ing and discharging the bulk capacitance is given by:
VRIPPLE,BOOST =IOUT(MAX) VOUT – VIN(MIN)
(
)
COUT VOUT ƒ
VRIPPLE,BUCK =VOUT VIN(MAX) – VOUT
( )
8LCOUT VIN(MAX) ƒ2
The steady ripple due to the voltage drop across the ESR
(effective series resistance) is given by:
V
ESR,BUCK
= ∆I
L(MAX)
ESR
V
ESR,BOOST
=I
L(MAX)
ESR
The LTM4609 is designed for low output voltage ripple.
The bulk output capacitors defined as COUT are chosen
with low enough ESR to meet the output voltage ripple and
transient requirements. COUT can be the low ESR tantalum
capacitor, the low ESR polymer capacitor or the ceramic
capacitor. Multiple capacitors can be placed in parallel to
meet the ESR and RMS current handling requirements. The
typical capacitance is 300µF. Additional output filtering may
be required by the system designer, if further reduction of
output ripple or dynamic transient spike is required. Table 3
shows a matrix of different output voltages and output
capacitors to minimize the voltage droop and overshoot
at a current transient.
Inductor Selection
The inductor is chiefly decided by the required ripple cur-
rent and the operating frequency. The inductor current
ripple ΔIL is typically set to 20% to 40% of the maximum
inductor current. In the inductor design, the worst cases
in continuous mode are considered as follows:
LBOOST V2IN VOUT(MAX) – VIN
(
)
V2OUT(MAX) ƒIOUT(MAX) Ripple%
LBUCK VOUT VIN(MAX) – VOUT
(
)
VIN(MAX) ƒIOUT(MAX) Ripple%
where:
ƒ is operating frequency, Hz
Ripple% is allowable inductor current ripple, %
VOUT(MAX) is maximum output voltage, V
VIN(MAX) is maximum input voltage, V
VOUT is output voltage, V
IOUT(MAX) is maximum output load current, A
The inductor should have low DC resistance to reduce the
I2R losses, and must be able to handle the peak inductor
current without saturation. To minimize radiated noise,
use a toroid, pot core or shielded bobbin inductor. Please
refer to Table 3 for the recommended inductors for dif-
ferent cases.
RSENSE Selection and Maximum Output Current
RSENSE is chosen based on the required inductor current.
Since the maximum inductor valley current at buck mode
is much lower than the inductor peak current at boost
mode, different sensing resistors are suggested to use
in buck and boost modes.
The current comparator threshold sets the peak of the
inductor current in boost mode and the maximum inductor
valley current in buck mode. In boost mode, the allowed
maximum average load current is:
IOUT(MAX,BOOST) =160mV
RSENSE
IL
2
V
IN
VOUT
where ΔIL is peak-to-peak inductor ripple current.
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applications inForMation
In buck mode, the allowed maximum average load cur-
rent is:
IOUT(MAX,BUCK) =
130mV
RSENSE
+
I
L
2
The maximum current sensing RSENSE value for the boost
mode is:
R
SENSE(MAX,BOOST)
=
2160mV VIN
2IOUT(MAX,BOOST) VOUT +∆ILVIN
The maximum current sensing RSENSE value for the buck
mode is:
RSENSE(MAX,BUCK) =
2130mV
2IOUT(MAX,BUCK) – ∆IL
A 20% to 30% margin on the calculated sensing resistor
is usually recommended. Please refer to Table 3 for the
recommended sensing resistors for different applications.
Soft-Start
The SS pin provides a means to soft-start the regulator.
A capacitor on this pin will program the ramp rate of the
output voltage. A 1.7µA current source will charge up the
external soft-start capacitor. This will control the ramp of
the internal reference and the output voltage. The total
soft-start time can be calculated as:
tSOFTSTART =
2.4V C
SS
1.7µA
When the RUN pin falls below 1.6V, then the soft-start
pin is reset to allow for proper soft-start control when
the regulator is enabled again. Current foldback and force
continuous mode are disabled during the soft-start process.
Do not apply more than 6V to the SS pin.
Run Enable
The RUN pin is used to enable the power module. The pin
can be driven with a logic input, not to exceed 6V.
The RUN pin can also be used as an undervoltage lockout
(UVLO) function by connecting a resistor from the input
supply to the RUN pin. The equation:
V_UVLO=
R1+R2
R2
1.6V
Power Good
The PGOOD pin is an open drain pin that can be used to
monitor valid output voltage regulation. This pin monitors
a ±7.5% window around the regulation point.
COMP Pin
This pin is the external compensation pin. The module
has already been internally compensated for most output
voltages. A spice model is available for other control loop
optimization.
Fault Conditions: Current Limit and Overcurrent
Foldback
LTM4609 has a current mode controller, which inherently
limits the cycle-by-cycle inductor current not only in steady
state operation, but also in transient. Refer to Table 3.
To further limit current in the event of an overload condi-
tion, the LTM4609 provides foldback current limiting. If the
output voltage falls by more than 70%, then the maximum
output current is progressively lowered to about 30% of
its full current limit value for boost mode and about 40%
for buck mode.
Standby Mode (STBYMD)
The standby mode (STBYMD) pin provides several choices
for start-up and standby operational modes. If the pin is
pulled to ground, the SS pin is internally pulled to ground,
preventing start-up and thereby providing a single control
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pin for turning off the controller. If the pin is left open or
decoupled with a capacitor to ground, the SS pin is internally
provided with a starting current, permitting external control
for turning on the controller. If the pin is connected to a
voltage greater than 1.25V, the internal regulator (INTVCC)
will be on even when the controller is shut down (RUN
pin voltage <1.6V). In this mode, the onboard 6V output
linear regulator can provide power to keep-alive functions
such as a keyboard controller.
INTVCC and EXTVCC
An internal P-channel low dropout regulator produces 6V
at the INTVCC pin from the VIN supply pin. INTVCC powers
the control chip and internal circuitry within the module.
The LTM4609 also provides the external supply voltage pin
EXTVCC. When the voltage applied to EXTVCC rises above
5.7V, the internal regulator is turned off and an internal
switch connects the EXTVCC pin to the INTVCC pin thereby
supplying internal power. The switch remains closed as long
as the voltage applied to EXTVCC remains above 5.4V. This
allows the MOSFET driver and control power to be derived
from the output when (5.7V < VOUT < 7V) and from the
internal regulator when the output is out of regulation (start-
up, short-circuit). If more current is required through the
EXTVCC switch than is specified, an external Schottky diode
can be interposed between the EXTVCC and INTVCC pins.
Ensure that EXTVCC ≤ VIN.
The following list summarizes the three possible connec-
tions for EXTVCC:
1. EXTVCC left open (or grounded). This will cause INTVCC
to be powered from the internal 6V regulator at the cost
of a small efficiency penalty.
2. EXTVCC connected directly to VOUT (5.7V < VOUT < 7V).
This is the normal connection for a 6V regulator and
provides the highest efficiency.
3. EXTVCC connected to an external supply. If an external
supply is available in the 5.5V to 7V range, it may be
used to power EXTVCC provided it is compatible with
the MOSFET gate drive requirements.
Thermal Considerations and Output Current Derating
In different applications, LTM4609 operates in a variety
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 de-
rating is necessary, considering ambient temperature,
airflow, input/output condition, and the need for increased
reliability.
The power loss curves in Figures 5 and 6 can be used
in coordination with the load current derating curves in
Figures 7 to 14 for calculating an approximate θJA for
the module. Column designation delineates between no
heat sink, and a BGA heat sink. Each of the load current
derating curves will lower the maximum load current as
a function of the increased ambient temperature to keep
the maximum junction temperature of the power module
at 115°C allowing a safe margin for the maximum operat-
ing temperature below 125°C. Each of the derating curves
and the power loss curve that corresponds to the correct
output voltage can be used to solve for the approximate
θJA of the condition.
DESIGN EXAMPLES
Buck Mode Operation
As a design example, use input voltage VIN = 12V to 36V,
VOUT = 12V and ƒ = 400kHz.
Set the PLLFLTR pin at 2.4V or more for 400kHz frequency
and connect FCB to ground for continuous current mode
operation. If a divider is used to set the frequency as shown
in Figure 16, the bottom resistor R3 is recommended not
to exceed 1kΩ.
To set the output voltage at 12V, the resistor RFB from VFB
pin to ground should be chosen as:
RFB =
0.8V 100k
VOUT – 0.8V ≈ 7.15k
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applications inForMation
To choose a proper inductor, we need to know the current
ripple at different input voltages. The inductor should
be chosen by considering the worst case in the practi-
cal operating region. If the maximum output power P is
120W at buck mode, we can get the current ripple ratio
of the current ripple ΔIL to the maximum inductor current
IL as follows:
IL
I
L
=(VIN VOUT )VOUT
2
V
IN
LƒP
Figure 3 shows the current ripple ratio at different input
voltages based on the inductor values: 2.5µH, 3.3µH, 4.7µH
and 6µH. If we need about 40% ripple current ratio at all
inputs, the 4.7µH inductor can be selected.
At buck mode, sensing resistor selection is based on
the maximum output current and the allowed maximum
sensing threshold 130mV.
RSENSE =
2130mV
2(P / VOUT )– ∆IL
Consider the safety margin about 30%, we can choose
the sensing resistor as 9mΩ.
For the input capacitor, use a low ESR sized capacitor to
handle the maximum RMS current. Input capacitors are
required to be placed adjacent to the module. In Figure 16,
the 10µF ceramic input capacitors are selected for their
ability to handle the large RMS current into the converter.
The 100µF bulk capacitor is only needed if the input source
impedance is compromised by long inductive leads or
traces.
For the output capacitor, the output voltage ripple and
transient requirements require low ESR capacitors. If
assuming that the ESR dominates the output ripple, the
output ripple is as follows:
∆V
OUT(P-P)
=ESR∆I
L
If a total low ESR of about 5mΩ is chosen for output
capacitors, the maximum output ripple of 21.5mV occurs
at the input voltage of 36V with the current ripple at 4.3A.
Boost Mode Operation
For boost mode operation, use input voltage VIN = 5V to
12V, VOUT = 12V and ƒ = 400kHz.
Set the PLLFLTR pin and RFB as in buck mode.
If the maximum output power P is 50W at boost mode
and the module efficiency η is about 90%, we can get
the current ripple ratio of the current ripple ΔIL to the
maximum inductor current IL as follows:
IL
IL
=(VOUT VIN )VIN2η
VOUT LƒP
Figure 3. Current Ripple Ratio at Different Inputs for Buck Mode
INPUT VOLTAGE VIN (V)
12 18
CURRENT RIPPLE RATIO
0.8
0.6
2.5µH
3.3µH
6µH
0.4
0.2
0
4609 F03
24 30 36
4.7µH
VOUT = 12V
ƒ = 400kHz
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Figure 4 shows the current ripple ratio at different input
voltages based on the inductor values: 1.5µH, 2.5µH,
3.3µH and 4.7µH. If we need 30% ripple current ratio at
all inputs, the 3.3µH inductor can be selected.
At boost mode, sensing resistor selection is based on
the maximum input current and the allowed maximum
sensing threshold 160mV.
RSENSE =
2160mV
2P
ηVIN(MIN)
+∆IL
Consider the safety margin about 30%, we can choose
the sensing resistor as 8mΩ.
For the input capacitor, only minimum capacitors are
needed to handle the maximum RMS current, since it
is a continuous input current at boost mode. A 100µF
capacitor is only needed if the input source impedance is
compromised by long inductive leads or traces.
Since the output capacitors at boost mode need to filter
the square wave current, more capacitors are expected
to achieve the same output ripples as the buck mode.
If assuming that the ESR dominates the output ripple,
the output ripple is as follows:
∆V
OUT(P-P)
=ESRI
L(MAX)
If a total low ESR about 5mΩ is chosen for output capaci-
tors, the maximum output ripple of 70mV occurs at the
input voltage of 5V with the peak inductor current at 14A.
An RC snubber is recommended on SW1 to obtain low
switching noise, as shown in Figure 17.
Wide Input Mode Operation
If a wide input range is required from 5V to 36V, the module
will work in different operation modes. If input voltage
VIN = 5V to 36V, VOUT = 12V and ƒ = 400kHz, the design
needs to consider the worst case in buck or boost mode
design. Therefore, the maximum output power is limited
to 60W. The sensing resistor is chosen at 8mΩ, the input
capacitor is the same as the buck mode design and the
output capacitor uses the boost mode design. Since the
maximum output ripple normally occurs at boost mode
in the wide input mode design, more inductor ripple cur-
rent, up to 150% of the inductor current, is allowed at
buck mode to meet the ripple design requirement. Thus,
a 3.3µH inductor is chosen at the wide input mode. The
maximum output ripple voltage is still 70mV if the total
ESR is about 5mΩ.
Additionally, the current limit may become very high when
the module runs at buck mode due to the low sensing
resistor used in the wide input mode operation.
Safety Considerations
The LTM4609 modules do not provide isolation from VIN
to VOUT. There is no internal fuse. If required, a slow blow
fuse with a rating twice the maximum input current needs
to be provided to protect each unit from catastrophic failure.
Figure 4. Current Ripple Ratio at Different Inputs for Boost Mode
INPUT VOLTAGE VIN (V)
5 7
CURRENT RIPPLE RATIO
0.8
0.6
0.4
0.2
0
4609 F04
9 11 126 8 10
1.5µH
2.5µH
3.3µH
4.7µH
VOUT = 12V
ƒ = 400kHz
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Table 3. Typical Components (ƒ = 400kHz)
COUT1 VENDORS PART NUMBER COUT2 VENDORS PART NUMBER
TDK C4532X7R1E226M (22µF, 25V) Sanyo 16SVP180MX (180µF, 16V), 20SVP150MX (150µF, 20V)
INDUCTOR VENDORS PART NUMBER RSENSE VENDORS PART NUMBER
Toko FDA1254 Vishay Power Metal Strip Resistors WSL1206-18
Sumida CDEP134, CDEP145, CDEP147 Panasonic Thick Film Chip Resistors ERJ12
VIN
(V)
VOUT
(V)
RSENSE
(0.5W RATING)
Inductor
(µH)
CIN
(CERAMIC)
CIN
(BULK)
COUT1
(CERAMIC)
COUT2
(BULK)
IOUT(MAX)*
(A)
5 10 2 × 16mW 0.5W 2.2 None 150µF 35V 4 × 22µF 25V 2 × 180µF 16V 4
15 10 2 × 18mW 0.5W 2.2 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 11
20 10 2 × 20mW 0.5W 3.3 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 10
24 10 2 × 18mΩ 0.5W 3.3 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 10
32 10 2 × 22mΩ 0.5W 4.7 2 × 10µF 50V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 9
36 10 2 × 22mΩ 0.5W 4.7 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 180µF 16V 9
6 12 2 × 14mΩ 0.5W 2.2 None 150µF 35V 4 × 22µF 25V 2 × 180µF 16V 4
16 12 2 × 16mW 0.5W 2.2 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 11
20 12 2 × 18mW 0.5W 3.3 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 10
24 12 2 × 18mΩ 0.5W 3.3 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 9
32 12 2 × 22mΩ 0.5W 4.7 2 × 10µF 50V 150µF 35V 2 × 22µF 25V 2 × 180µF 16V 9
36 12 2 × 22mΩ 0.5W 4.7 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 180µF 16V 9
5 16 2 × 18mW 0.5W 3.3 None 150µF 35V 4 × 22µF 25V 2 × 150µF 20V 2.5
8 16 2 × 16mW 0.5W 3.3 None 150µF 35V 4 × 22µF 25V 2 × 150µF 20V 4
12 16 2 × 14mW 0.5W 2.2 None 150µF 35V 4 × 22µF 25V 2 × 150µF 20V 8
20 16 2 × 20mW 0.5W 2.2 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 150µF 20V 10
24 16 2 × 20mΩ 0.5W 3.3 2 × 10µF 25V 150µF 35V 2 × 22µF 25V 2 × 150µF 20V 10
32 16 2 × 22mΩ 0.5W 4.7 2 × 10µF 50V 150µF 35V 2 × 22µF 25V 2 × 150µF 20V 9
36 16 2 × 22mΩ 0.5W 6 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 150µF 20V 9
5 20 2 × 18mΩ 0.5W 3.3 NONE 150µF 50V 4 × 22µF 25V 2 × 150µF 50V 2
10 20 2 × 18mΩ 0.5W 3.3 NONE 150µF 50V 4 × 22µF 25V 2 × 150µF 50V 5
32 20 1 × 12mΩ 0.5W 6 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 150µF 50V 9
36 20 1 × 13mΩ 0.5W 8 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 150µF 50V 8
5 24 2 × 16mΩ 0.5W 3.3 NONE 150µF 50V 4 × 22µF 25V 2 × 150µF 50V 1.5
12 24 2 × 18mΩ 0.5W 4.7 NONE 150µF 50V 4 × 22µF 25V 2 × 150µF 50V 5
32 24 1 × 14mΩ 0.5W 4.7 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 150µF 50V 8
36 24 1 × 13mΩ 0.5W 7 2 × 10µF 50V 150µF 50V 2 × 22µF 25V 2 × 150µF 50V 8
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Figure 5. Boost Mode Operation Figure 6. Buck Mode Operation
applications inForMation
VIN
(V)
VOUT
(V)
RSENSE
(0.5W RATING)
Inductor
(µH)
CIN
(CERAMIC)
CIN
(BULK)
COUT1
(CERAMIC)
COUT2
(BULK)
IOUT(MAX)*
(A)
5 30 2 × 16mΩ 0.5W 3.3 NONE 150µF 50V 4 × 22µF 50V 2 × 150µF 50V 1.3
12 30 2 × 14mΩ 0.5W 4.7 NONE 150µF 50V 4 × 22µF 50V 2 × 150µF 50V 3
32 30 1 × 12mΩ 0.5W 2.5 2 × 10µF 50V 150µF 50V 2 × 22µF 50V 2 × 150µF 50V 8
36 30 1 × 13mΩ 0.5W 4.7 2 × 10µF 50V 150µF 50V 2 × 22µF 50V 2 × 150µF 50V 8
5 34 2 × 18mΩ 0.5W 3.3 NONE 150µF 50V 4 × 22µF 50V 2 × 150µF 50V 1
12 34 2 × 16mΩ 0.5W 4.7 NONE 150µF 50V 4 × 22µF 50V 2 × 150µF 50V 3
24 34 1 × 12mΩ 0.5W 5.6 NONE 150µF 50V 4 × 22µF 50V 2 × 150µF 50V 5
36 34 1 × 12mΩ 0.5W 2.5 2 × 10µF 50V 150µF 50V 2 × 22µF 50V 2 × 150µF 50V 8
INDUCTOR MANUFACTURER WEBSITE PHONE NUMBER
Sumida www.sumida.com 408-321-9660
Toko www.toko.com 847-297-0070
SENSING RESISTOR MANUFACTURER WEBSITE PHONE NUMBER
Panasonic www.panasonic.com/industrial/components 949-462-1816
KOA www.koaspeer.com 814-362-5536
Vishay www.vishay.com 800-433-5700
*Maximum load current is based on the Linear Technology DC1198A at room temperature with natural convection. Poor board layout design may
decrease the maximum load current.
LOAD CURRENT (A)
0
0
POWER LOSS (W)
1
3
4
5
7
6
1
4609 F05
2
23
5VIN TO 16VOUT
5VIN TO 30VOUT
LOAD CURRENT (A)
0
0
POWER LOSS (W)
1
3
4
5
7
6
123456
4609 F06
2
789
32VIN TO 12VOUT
36VIN TO 20VOUT
Table 3. Typical Components (ƒ = 400kHz) Continued
(Power Loss includes all external components)
typical applications
LTM4609
18
4609ff
For more information www.linear.com/LTM4609
typical applications
Figure 9. 5VIN to 30VOUT without Heat Sink Figure 10. 5VIN to 30VOUT with Heat Sink
Figure 11. 32VIN to 12VOUT without Heat Sink Figure 12. 32VIN to 12VOUT with Heat Sink
Figure 7. 5VIN to 16VOUT without Heat Sink Figure 8. 5VIN to 16VOUT with Heat Sink
AMBIENT TEMPERATURE (°C)
25
0
MAXIMUM LOAD CURRENT (A)
0.5
1.5
2.0
2.5
3.0
35 45 55 65 75 85
4609 F07
1.0
95 105 115
5VIN TO 16VOUT WITH 0LFM
5VIN TO 16VOUT WITH 200LFM
5VIN TO 16VOUT WITH 400LFM
AMBIENT TEMPERATURE (°C)
25
0
MAXIMUM LOAD CURRENT (A)
0.5
1.5
2.0
2.5
3.0
45 65 85
4609 F08
1.0
105 125
5VIN TO 16VOUT WITH 0LFM
5VIN TO 16VOUT WITH 200LFM
5VIN TO 16VOUT WITH 400LFM
AMBIENT TEMPERATURE (°C)
0
MAXIMUM LOAD CURRENT (A)
0.25
0.75
1.00
1.25
1.50
25 4535 55 7565
4609 F09
0.50
85 95 105
5VIN TO 30VOUT WITH 0LFM
5VIN TO 30VOUT WITH 200LFM
5VIN TO 30VOUT WITH 400LFM
AMBIENT TEMPERATURE (°C)
0
MAXIMUM LOAD CURRENT (A)
0.25
0.75
1.00
1.25
1.50
25 4535 55 7565
4609 F10
0.50
85 95 105
5VIN TO 30VOUT WITH 0LFM
5VIN TO 30VOUT WITH 200LFM
5VIN TO 30VOUT WITH 400LFM
AMBIENT TEMPERATURE (°C)
25 35 45 55 65 75 85
MAXIMUM LOAD CURRENT (A)
95
4609 F12
32VIN TO 12VOUT WITH 0LFM
32VIN TO 12VOUT WITH 200LFM
32VIN TO 12VOUT WITH 400LFM
10
8
9
4
2
1
3
5
7
6
0
AMBIENT TEMPERATURE (°C)
25 35 45 55 65 75 85
MAXIMUM LOAD CURRENT (A)
95
4609 F11
32VIN TO 12VOUT WITH 0LFM
32VIN TO 12VOUT WITH 200LFM
32VIN TO 12VOUT WITH 400LFM
10
8
7
9
4
3
2
1
6
5
0
LTM4609
19
4609ff
For more information www.linear.com/LTM4609
Table 4. Boost Mode
DERATING CURVE VOUT (V) POWER LOSS CURVE AIR FLOW (LFM) HEAT SINK θJA (°C/W)*
Figure 7, 9 16, 30 Figure 5 0 None 11.4
Figure 7, 9 16, 30 Figure 5 200 None 8.5
Figure 7, 9 16, 30 Figure 5 400 None 7.5
Figure 8, 10 16, 30 Figure 5 0 BGA Heat Sink 11.0
Figure 8, 10 16, 30 Figure 5 200 BGA Heat Sink 7.9
Figure 8, 10 16, 30 Figure 5 400 BGA Heat Sink 7.1
Table 5. Buck Mode
DERATING CURVE VOUT (V) POWER LOSS CURVE AIR FLOW (LFM) HEAT SINK θJA (°C/W)*
Figure 11, 13 12, 20 Figure 6 0 None 8.2
Figure 11, 13 12, 20 Figure 6 200 None 5.9
Figure 11, 13 12, 20 Figure 6 400 None 5.4
Figure 12, 14 12, 20 Figure 6 0 BGA Heat Sink 7.5
Figure 12, 14 12, 20 Figure 6 200 BGA Heat Sink 5.3
Figure 12, 14 12, 20 Figure 6 400 BGA Heat Sink 4.8
HEAT SINK MANUFACTURER PART NUMBER WEBSITE
Aavid Thermalloy 375424B00034G www.aavidthermalloy.com
Cool Innovations 4-050503P to 4-050508P www.coolinnovations.com
*The results of thermal resistance from junction to ambient θJA are based on the demo board DC 1198A. Thus, the maximum temperature on board is treated
as the junction temperature (which is in the µModule regulator for most cases) and the power losses from all components are counted for calculations. It
has to be mentioned that poor board design may increase the θJA.
Figure 13. 36VIN to 20VOUT without Heat Sink Figure 14. 36VIN to 20VOUT with Heat Sink
typical applications
AMBIENT TEMPERATURE (°C)
0
MAXIMUM LOAD CURRENT (A)
1
5
6
7
8
25 554535 65
4609 F13
2
4
3
8575 95 105
36VIN TO 20VOUT WITH 0LFM
36VIN TO 20VOUT WITH 200LFM
36VIN TO 20VOUT WITH 400LFM
AMBIENT TEMPERATURE (°C)
0
MAXIMUM LOAD CURRENT (A)
1
5
6
7
8
25 554535 65
4609 F14
2
4
3
8575 95 105
36VIN TO 20VOUT WITH 0LFM
36VIN TO 20VOUT WITH 200LFM
36VIN TO 20VOUT WITH 400LFM
applications inForMation
LTM4609
20
4609ff
For more information www.linear.com/LTM4609
VOUT
COUT
VIN
RSENSE
RSENSE
PGND
SW1
L1
SW2
PGND
SGND
CIN
4609 F15
KELVIN CONNECTIONS TO RSENSE
+ –
applications inForMation
Layout Checklist/Example
The high integration of LTM4609 makes the PCB board
layout very simple and easy. However, to optimize its electri-
cal and thermal performance, some layout considerations
are still necessary.
Use large PCB copper areas for high current path, includ-
ing VIN, RSENSE, SW1, SW2, PGND and VOUT. It helps to
minimize the PCB conduction loss and thermal stress.
Place high frequency input and output ceramic capaci-
tors next to the VIN, PGND and VOUT pins to minimize
high frequency noise
Route SENSE and SENSE+ leads together with minimum
PC trace spacing. Avoid sense lines passing through
noisy areas, such as switch nodes.
Place a dedicated power ground layer underneath the
unit.
To minimize the via conduction loss and reduce module
thermal stress, use multiple vias for interconnection
between the top layer and other power layers
Do not put vias directly on pads, unless the vias are
capped.
Use a separated SGND ground copper area for com-
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit.
Figure 15. gives a good example of the recommended
layout.
Figure 15. Recommended PCB Layout
(LGA Shown, for BGA Use Circle Pads)
LTM4609
21
4609ff
For more information www.linear.com/LTM4609
VOUT
PGOOD
FCBRUN
SW1
COMP
SW2
INTVCC
RSENSE
EXTVCC
SENSE
STBYMD
PLLFLTR
SS
VFB
SGND
PLLIN
LTM4609
R2
9mΩ
L1
4.7µH
RFB
7.15k
R1
1.5k
R3
1k
100µF
25V
4609 TA02
VOUT
12V
10A
VIN
PGND
VIN
12V TO 36V
C3
0.1µF
10µF
50V
×2 +
ON/OFF
SENSE+
Figure 16. Buck Mode Operation with 12V to 36V Input
typical applications
VOUT
PGOOD
FCBRUN
SW1
SW2
EXTVCC
STBYMD
SS
VFB
SGND
PLLIN
LTM4609
L1
3.3µH
RFB
7.15k
22µF
25V
×2
330µF
25V
4609 TA03
VOUT
12V
4A
VIN
PGND
VIN
5V TO 12V
C3
0.1µF
4.7µF
35V +
ON/OFF
COMP
INTVCC
RSENSE
SENSE
PLLFLTR
R2
8mΩ
SENSE+
2200pF
OPTIONAL
FOR LOW
SWITCHING NOISE
R1
1.5k
R3
1k
Figure 17. Boost Mode Operation with 5V to 12V Input with Low Switching Noise (Optional)
LTM4609
22
4609ff
For more information www.linear.com/LTM4609
typical applications
VOUT
PGOOD
FCBRUN
SW1
SW2
EXTVCC
STBYMD
SS
VFB
SGND
PLLIN
LTM4609
RFB
7.15k
22µF
25V
×4
330µF
25V
4609 TA04
VOUT
12V
4A
VIN
PGND
VIN
5V TO 36V
C3
0.1µF
10µF
50V
×2 +
ON/OFF
COMP
INTVCC
RSENSE
SENSE
PLLFLTR
R2
8mΩ
SENSE+
L1
3.3µH
2200pF
R1
1.5k
R3
1k
Figure 18. Wide Input Mode with 5V to 36V Input, 12V at 4A Output
VOUT
PGOOD
FCBRUN
SW1
SW2
EXTVCC
STBYMD
SS
VFB
SGND
PLLIN
LTM4609 L1
4.7µH
RFB
2.55k
220µF
50V
4609 TA05
VOUT
32V
2A
VIN
PGND
VIN
8V TO 36V
C3
0.1µF
10µF
50V
×2 +
ON/OFF
COMP
INTVCC
RSENSE
SENSE
PLLFLTR
R2
9mΩ
SENSE+
R1
1.5k
R3
1k
Figure 19. 32V at 2A Design
LTM4609
23
4609ff
For more information www.linear.com/LTM4609
typical applications
Figure 20. Two-Phase Parallel, 12V at 8A Design
VOUT
PGOOD
FCB
RUN
SW1COMP
SW2INTVCC
EXTVCC
STBYMD
SS
VFB
SGND
PLLIN
LTM4609 L2
3.3µH
C4
22µF
25V
×2
330µF
25V
4609 TA06
CLOCK SYNC 180° PHASE
CLOCK SYNC 0° PHASE
VIN
PGND
10µF
50V +
VOUT
PGOOD
FCBRUN
SW1COMP
SW2INTVCC
EXTVCC
PLLFLTR
PLLFLTR
OUT1V+
OUT2
MOD
GND
SET
LTC6908-1
STBYMD
SS
VFB
SGND
PLLIN
LTM4609 L1
3.3µH
RFB*
3.57k
R4
324k
C2
22µF
25V
×2
330µF
25V
VOUT
12V
8A
2-PHASE OSCILLATOR
VIN
PGND
VIN
5V TO 36V
C3
0.1µF
10µF
50V +
R5
100k
C1
0.1µF
5.1V
ZENER
RSENSE
SENSE
R3
8mΩ
SENSE+
RSENSE
SENSE
R2
8mΩ
SENSE+
5.1V
200Ω
*RFB IS SELECTED USING
WHERE N IS THE NUMBER
OF PARALLELED MODULES.
VOUT =0.8V
100k
N
+RFB
RFB
LTM4609
24
4609ff
For more information www.linear.com/LTM4609
package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
5. PRIMARY DATUM -Z- IS SEATING PLANE
6. THE TOTAL NUMBER OF PADS: 141
7 PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
LAYOUT CAREFULLY
!
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
2. ALL DIMENSIONS ARE IN MILLIMETERS
BALL DESIGNATION PER JESD MS-028 AND JEP95
4
3
DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
PACKAGE TOP VIEW
4
PIN “A1”
CORNER
X
Y
aaa Z
aaa Z
PACKAGE BOTTOM VIEW
3
SEE NOTES
SUGGESTED PCB LAYOUT
TOP VIEW
LGA 141 1212 REV B
LTMXXXXXX
µModule
TRAY PIN 1
BEVEL PACKAGE IN TRAY LOADING ORIENTATION
COMPONENT
PIN “A1
0.0000
0.0000
D
Eb
e
e
b
F
G
LGA Package
141-Lead (15mm × 15mm × 2.82mm)
(Reference LTC DWG # 05-08-1840 Rev B)
0.6350
0.6350
1.9050
1.9050
3.1750
3.1750
4.4450
4.4450
5.7150
5.7150
6.9850
6.9850
6.9850
5.7150
5.7150
4.4450
4.4450
3.1750
3.1750
1.9050
1.9050
0.6350
0.6350
6.9850
DETAIL B
PACKAGE SIDE VIEW
bbb Z
SYMBOL
A
b
D
E
e
F
G
H1
H2
aaa
bbb
eee
MIN
2.72
0.60
0.27
2.45
NOM
2.82
0.63
15.00
15.00
1.27
13.97
13.97
0.32
2.50
MAX
2.92
0.66
0.37
2.55
0.15
0.10
0.05
NOTES
DIMENSIONS
TOTAL NUMBER OF LGA PADS: 141
DETAIL B
SUBSTRATE
MOLD
CAP
Z
H2
H1
A
DETAIL A
0.630 ±0.025 SQ. 143x
SYXeee
DETAIL A
C(0.22 x 45°)
PAD 1
F
G
H
M
L
J
K
E
A
B
C
D
2 14 356712 891011
7
SEE NOTES
LTM4609
25
4609ff
For more information www.linear.com/LTM4609
package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
2. ALL DIMENSIONS ARE IN MILLIMETERS
BALL DESIGNATION PER JESD MS-028 AND JEP95
5. PRIMARY DATUM -Z- IS SEATING PLANE
6. SOLDER BALL COMPOSITION IS 96.5% Sn/3.0% Ag/0.5% Cu
4
3
DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
PACKAGE TOP VIEW
4
PIN “A1”
CORNER
X
Y
aaa Z
aaa Z
PACKAGE BOTTOM VIEW
PIN 1
3
SEE NOTES
SUGGESTED PCB LAYOUT
TOP VIEW
BGA 141 1112 REV B
LTMXXXXXX
µModule
TRAY PIN 1
BEVEL PACKAGE IN TRAY LOADING ORIENTATION
COMPONENT
PIN “A1
DETAIL A
0.0000
0.0000
DETAIL A
Øb (141 PLACES)
DETAIL B
SUBSTRATE
0.27 – 0.37
2.45 – 2.55
// bbb Z
D
A
A1
b1
ccc Z
DETAIL B
PACKAGE SIDE VIEW
MOLD
CAP
Z
MX YZddd
MZeee
0.630 ±0.025 Ø 141x
SYMBOL
A
A1
A2
b
b1
D
E
e
F
G
aaa
bbb
ccc
ddd
eee
MIN
3.22
0.50
2.72
0.60
0.60
NOM
3.42
0.60
2.82
0.75
0.63
15.0
15.0
1.27
13.97
13.97
MAX
3.62
0.70
2.92
0.90
0.66
0.15
0.10
0.20
0.30
0.15
NOTES
DIMENSIONS
TOTAL NUMBER OF BALLS: 141
Eb
e
e
b
A2
F
G
BGA Package
141-Lead (15mm × 15mm × 3.42mm)
(Reference LTC DWG # 05-08-1899 Rev B)
0.6350
0.6350
1.9050
1.9050
3.1750
3.1750
4.4450
4.4450
5.7150
5.7150
6.9850
6.9850
6.9850
5.7150
5.7150
4.4450
4.4450
3.1750
3.1750
1.9050
1.9050
0.6350
0.6350
6.9850
F
G
H
M
L
J
K
E
A
B
C
D
2 14 356712 891011
7 PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE
LAYOUT CAREFULLY
!
7
SEE NOTES
LTM4609
26
4609ff
For more information www.linear.com/LTM4609
package Description
Pin Assignment Table 6 (Arranged by Pin Number)
PIN NAME FUNCTION PIN NAME FUNCTION PIN NAME FUNCTION PIN NAME FUNCTION PIN NAME FUNCTION PIN NAME FUNCTION
A1 PGND C1 PGND E1 VOUT G1 VOUT J1 SW1 L1 SW1
A2 PGND C2 PGND E2 VOUT G2 VOUT J2 SW1 L2 SW1
A3 PGND C3 PGND E3 PGND G3 VOUT J3 SW1 L3 SW1
A4 SENSE+ C4 PGND E4 PGND G4 VOUT J4 SW1 L4 SW1
A5 SENSE C5 PGND E5 PGND G5 RSENSE J5 RSENSE L5 RSENSE
A6 SS C6 PGND E6 PGND G6 RSENSE J6 RSENSE L6 RSENSE
A7 SGND C7 PGND E7 PGND G7 RSENSE J7 RSENSE L7 SW2
A8 RUN C8 PGND E8 PGND G8 RSENSE J8 SW2 L8 SW2
A9 FCB C9 PGND E9 PGND G9 RSENSE J9 SW2 L9 SW2
A10 STBYMD C10 PGND E10 PGND G10 RSENSE J10 VIN L10 VIN
A11 PGND C11 PGND E11 PGND G11 RSENSE J11 VIN L11 VIN
A12 PGND C12 PGND E12 PGND G12 RSENSE J12 VIN L12 VIN
B1 PGND D1 PGND F1 VOUT H1 VOUT K1 SW1 M1 SW1
B2 PGND D2 PGND F2 VOUT H2 VOUT K2 SW1 M2 SW1
B3 PGND D3 PGND F3 VOUT H3 VOUT K3 SW1 M3 SW1
B4 PGND D4 PGND F4 VOUT H4 VOUT K4 SW1 M4 SW1
B5 PGOOD D5 PGND F5 INTVCC H5 RSENSE K5 RSENSE M5 RSENSE
B6 VFB D6 PGND F6 EXTVCC H6 RSENSE K6 RSENSE M6 RSENSE
B7 COMP D7 PGND F7 H7 RSENSE K7 SW2 M7 SW2
B8 PLLFLTR D8 PGND F8 H8 RSENSE K8 SW2 M8 SW2
B9 PLLIN D9 PGND F9 H9 RSENSE K9 SW2 M9 SW2
B10 PGND D10 PGND F10 RSENSE H10 RSENSE K10 VIN M10 VIN
B11 PGND D11 PGND F11 RSENSE H11 RSENSE K11 VIN M11 VIN
B12 PGND D12 PGND F12 RSENSE H12 RSENSE K12 VIN M12 VIN
LTM4609
27
4609ff
For more information www.linear.com/LTM4609
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.
revision history
REV DATE DESCRIPTION PAGE NUMBER
B 10/10 MP-grade part added. Reflected throughout the data sheet. 1-26
C 03/12 Added the BGA Package option and updated the Typical Application.
Updated the Pin Configuration and Order Information sections.
Updated Note 2.
Added INTVCC maximum load current.
Updated the recommended heat sinks table.
Added BGA Package drawing.
Updated the Related Parts table.
1
2
4
7
19
25
28
D 12/12 Add to Absolute Maximum Ratings and Thermal Resistance figures
Augment INTVCC limits
Update Note 2 and Note 3
Update Related Parts table
2
4
4
28
E 1/14 Added SnPb terminal finish product option 1, 2
F 4/14 Removed CLOCK SYNC, Figures 16, 17, 18, 19 21, 22
(Revision history begins at Rev B)
LTM4609
28
4609ff
For more information www.linear.com/LTM4609
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
LINEAR TECHNOLOGY CORPORATION 2009
LT 0414 REV F • PRINTED IN USA
(408) 432-1900 FAX: (408) 434-0507 www.linear.com/LTM4609
PART NUMBER DESCRIPTION COMMENTS
LTC3780 36V Buck-Boost Controller Synchronous Operation; Single Inductor, 4V ≤ VIN ≤ 36V, 0.8V ≤ VOUT ≤ 30V
LTC3785 10V Buck-Boost Controller Synchronous, No RSENSE™, 2.7V ≤ VIN ≤ 10V, 2.7V ≤ VOUT ≤ 10V
LTM4601/LTM4601A 12A DC/DC µModule Regulator with PLL, Output
Tracking/ Margining and Remote Sensing
Synchronizable, PolyPhase
®
Operation to 48A, LTM4601-1 Has No Remote
Sensing
LTM4603 6A DC/DC µModule with PLL and Output
Tracking/Margining and Remote Sensing
Synchronizable, PolyPhase Operation, LTM4603-1 Version Has No Remote
Sensing, Pin Compatible with the LTM4601
LTM4604A 4A, Low VIN, DC/DC µModule Regulator 2.375V ≤ VIN ≤ 5.5V, 0.8V ≤ VOUT ≤ 5V, 9mm × 15mm × 2.32mm
LTM4605/LTM4607 5A High Efficiency Buck-Boost DC/DC µModule
Regulators
Pin Compatible with LTM4609, Lower Voltage Versions of the LTM4609
LTM4606/LTM4612 Ultralow Noise DC/DC µModule Regulators Low EMI, LTM4606 Verified by Xilinx to Power Rocket IO™, CISPR22 Compliant
LTM4608A 8A, Low VIN, DC/DC µModule Regulator 2.7V ≤ VIN ≤ 5.5V, 0.6V ≤ VOUT ≤ 5V, 9mm × 15mm × 2.82mm
LTM4627 20V, 15A DC/DC Step-Down µModule Regulator 4.5V ≤ VIN ≤ 20V, 0.6V ≤ VOUT ≤ 5V, PLL Input, VOUT Tracking, Remote Sense
Amplifier, 15mm × 15mm × 4.32mm LGA or 15mm × 15mm × 4.92mm BGA
LTC2978 Octal Digital Power Supply Manager with EEPROM I2C/PMBus Interface, Configuration EEPROM, Fault Logging, 16-Bit ADC with
±0.25% TUE, 3.3V to 15V Operation
LTC2974 Quad Digital Power Supply Manager with EEPROM I2C/PMBus Interface, Configuration EEPROM, Fault Logging, Per Channel
Voltage, Current and Temperature Measurements
LTC3880 Dual Output PolyPhase Step-Down DC/DC
Controller with Digital Power System
Management
I2C/PMBus Interface, Configuration EEPROM, Fault Logging, ±0.5 Output
Voltage Accuracy, MOSFET Gate Drivers
package photos
relateD parts

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