LINER LTM8020 Complete switch mode power supply Datasheet

LTM8027
60V, 4A DC/DC
µModule Regulator
Features
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Description
Complete Switch Mode Power Supply
Wide Input Voltage Range: 4.5V to 60V
(7.5V Minimum Voltage to Start)
Wide Output Voltage Range: 2.5V to 24V
(See Table 2)
4A Output Current
Programmable Soft-Start
9µA Shutdown Supply Current
Selectable Switching Frequency Current Mode
Control
Up to 95% Efficiency
Pb-Free (e4) RoHS Compliant Package with
Gold Pad Finish
Tiny, Low Profile (15mm × 15mm × 4.32mm)
Surface Mount LGA Package
The LTM®8027 is a complete 4A, DC/DC step-down power
supply. Included in the package are the switching controller, power switches, inductor and all support components.
Operating over an input voltage range of 4.5V to 60V (7.5V
minimum voltage to start), the LTM8027 supports output
voltages up to 24V, and a switching frequency range of
100kHz to 500kHz, each set by a single resistor. Only the
bulk input and output filter capacitors are needed to finish
the design.
The low profile package (4.32mm) enables utilization of
unused space on the bottom of PC boards for high density point of load regulation. A built-in soft-start timer is
adjustable with a small capacitor.
The LTM8027 is packaged in a thermally enhanced, compact
(15mm × 15mm) and low profile (4.32mm) over-molded
land grid array (LGA) package suitable for automated
assembly by standard surface mount equipment. The
LTM8027 is Pb-free and RoHS compliant.
Applications
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12V and 42V Automotive and Heavy Equipment
48V Telecom Power Supplies
Avionics and Industrial Control Systems
Distributed Power Converters
L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical Application
48W, 16VIN to 60VIN DC/DC µModule® Regulator
4.7µF
×2
VIN
1M
48.7k
LTM8027
RUN
BIAS1
SS
BIAS2
SYNC
AUX
RT
ADJ
GND
100
VOUT
12V
4A
VOUT
24VIN
90
80
22µF
×4
56.2k
3845 TA01a
EFFICIENCY (%)
VIN
16V TO 60V
Efficiency vs Load
70
60
50
40
30
20
10
0
0
1
2
LOAD (A)
3
4
8027 TA01b
8027fb
1
LTM8027
Absolute Maximum Ratings
Pin Configuration
(Note 1)
VIN Voltage.................................................................65V
BIAS1.........................................................................15V
BIAS2.........................................................................24V
SYNC, ADJ, RT, RUN, SS Voltages...............................5V
Current into RUN Pin (Note 2)...................................1mA
VOUT, AUX..................................................................25V
Current Out of AUX.............................................. 200mA
Internal Operating Temperature (Note 3)
E-, I-Grade.......................................... –40°C to 125°C
MP-Grade........................................... –55°C to 125°C
Maximum Soldering Temperature.......................... 245°C
Storage Temperature Range................... –55°C to 125°C
TOP VIEW
11
10
9
8
AUX 7
BIAS1 6
SS 5
RUN 4
BIAS2 3
ADJ 2
1
VOUT
BANK 1
GND
BANK 2
VIN
BANK 3
A B C D E F G H J K L
SYNC
RT
LGA PACKAGE
113-LEAD (15mm × 15mm × 4.32mm)
TJMAX = 125°C, θJA = 12.2°C/W, θJC(TOP) = 9.3°C/W,
θJC(BOTTOM) = 3.6°C/W, θJBOARD = 7.54°C/W
θ VALUES DETERMINED PER JESD 51-9
WEIGHT = 2.6 GRAMS
Order Information
LEAD FREE FINISH
TRAY
PART MARKING
PACKAGE DESCRIPTION
LTM8027EV#PBF
LTM8027EV#PBF
LTM8027V
113-Lead (15mm × 15mm × 4.32mm) LGA –40°C to 125°C
TEMPERATURE RANGE (Note 3)
LTM8027IV#PBF
LTM8027IV#PBF
LTM8027V
113-Lead (15mm × 15mm × 4.32mm) LGA –40°C to 125°C
LTM8027MPV#PBF
LTM8027MPV#PBF
LTM8027V
113-Lead (15mm × 15mm × 4.32mm) LGA –55°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
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 = 20V, BIAS1 = BIAS2 = 10V, RUN = 2V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
VIN
Input DC Voltage
(Note 5)
VOUT
Maximum Output DC Voltage
0A < IOUT ≤ 4A, VIN = 48V
IOUT
Output DC Current
VIN ≤ 60V, VOUT = 12V, (Note 4)
VIN(START)
Minimum Start Voltage
∆VOUT/∆VIN
Line Regulation
VOUT = 12V, 15V< VIN < 60V, ILOAD = 4A
∆VOUT/∆ILOAD
Load Regulation
VUVLO(RISING)
Input Undervoltage Lockout Threshold
(Rising)
VUVLO(FALLING)
Input Undervoltage Lockout Threshold
(Falling)
MIN
l
TYP
4.5
MAX
60
24
0
UNITS
V
V
4
A
7.5
V
0.2
%
VOUT = 12V, VIN = 24V, 0A < ILOAD ≤ 4A
0.2
%
(Note 5)
4.6
V
(Note 5)
3.7
V
8027fb
2
LTM8027
Electrical Characteristics
The l denotes the specifications which apply over the full internal operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 20V, BIAS1 = BIAS2 = 10V, RUN = 2V, unless otherwise noted.
SYMBOL
PARAMETER
VADJ
ADJ Voltage
CONDITIONS
MIN
l
IQ(VIN)
Quiescent Current into IN
VBIAS1
BIAS1 Undervoltage Lockout (Rising)
BIAS1 Undervoltage Lockout (Falling)
IBIAS1
Current into BIAS1
VBIAS2
TYP
1.224
1.215
VBIAS = VAUX, VOUT = 12VDC, No Load
VRUN = 0V
MAX
UNITS
1.238
1.245
V
V
39
9
mA
µA
6.5
6
V
V
25
25
mA
µA
Minimum BIAS2 Voltage
3
V
IBIAS2
Current Into BIAS2
1
µA
VBIAS1(MINOV)
Minimum Voltage to Overdrive Internal
Regulator (INTVCC)
8.5
V
No Load
RUN = 0V
RFB
Internal Feedback Resistor
499
kΩ
VRUN(RISING)
RUN Enable Voltage (Rising)
1.4
V
VRUN(FALLING)
RUN Enable Voltage (Falling)
1.2
V
fSW
Switching Frequency
100
500
kHz
kHz
RSYNC
SYNC Input Resistance
40
kΩ
VSYNC(TH)
SYNC Voltage Threshold
ISS
Soft-Start Charging Current
RT = 187kΩ
RT = 23.7kΩ
fSYNC = 350kHz
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 RUN pin is internally clamped to 5V.
Note 3: The LTM8027E is guaranteed to meet performance specifications
from 0°C to 125°C internal operating temperature. 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 LTM8027I is guaranteed to meet specifications over the full
l
2.3
V
2
µA
–40°C to 125°C internal operating temperature range. The LTM8027MP
is guaranteed to meet specifications over the full –55°C to 125°C
internal operating range. Note that the maximum internal temperature is
determined by specific operating conditions in conjunction with board
layout, the rated package thermal resistance and other environmental
factors.
Note 4: The maximum continuous output current may be derated by the
LTM8027 junction temperature.
Note 5: VIN voltages below the start-up threshold (7.5V) are only
supported when BIAS1 is externally driven above 6.5V.
8027fb
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LTM8027
Typical Performance Characteristics (TA = 25°C unless otherwise noted)
100
Efficiency vs Load, VOUT = 2.5V
100
80
80
70
70
40
30
5VIN
12VIN
24VIN
36VIN
20
10
0
0
1
2
LOAD (A)
60
50
40
5VIN
12VIN
24VIN
36VIN
48VIN
60VIN
30
20
10
0
4
3
0
1
2
LOAD (A)
50
40
Efficiency vs Load, VOUT = 8V
100
10
0
Efficiency vs Load, VOUT = 12V
100
80
80
70
70
70
40
30
12VIN
24VIN
36VIN
48VIN
60VIN
20
10
0
0
1
2
LOAD (A)
60
50
40
30
24VIN
36VIN
48VIN
60VIN
20
10
0
4
3
0
1
2
LOAD (A)
90
80
80
70
70
EFFICIENCY (%)
90
40
30
24VIN
36VIN
48VIN
60VIN
20
10
0
0
1
2
LOAD (A)
3
40
30
24VIN
36VIN
48VIN
60VIN
1
0
2
LOAD (A)
8027 G06
1.2
60
50
40
30
0
4
3
Input Current
vs VIN Output Shorted
1.0
36VIN
48VIN
60VIN
10
8027 G07
50
0
Efficiency vs Load, VOUT = 24V
20
4
60
10
INPUT CURRENT (A)
100
50
Efficiency vs Load, VOUT = 15V
8027 G05
Efficiency vs Load, VOUT = 18V
60
4
3
20
4
3
8027 G04
100
2
LOAD (A)
90
EFFICIENCY (%)
90
80
50
1
0
8027 G03
90
60
12VIN
24VIN
36VIN
48VIN
60VIN
30
8027 G02
EFFICIENCY (%)
EFFICIENCY (%)
60
20
4
3
8027 G01
100
EFFICIENCY (%)
80
50
Efficiency vs Load, VOUT = 5V
90
70
60
EFFICIENCY (%)
100
90
EFFICIENCY (%)
EFFICIENCY (%)
90
Efficiency vs Load, VOUT = 3.3V
0
1
2
LOAD (A)
3
0.8
0.6
0.4
0.2
4
8027 G08
0
0
10
40
30
50
20
INPUT VOLTAGE (V)
60
70
8027 G09
8027fb
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LTM8027
Typical Performance Characteristics (TA = 25°C unless otherwise noted)
3000
3500
5VIN
12VIN
24VIN
36VIN
2000
1500
1000
2500
2000
0
3
4
1600
1400
1200
1000
0
2
LOAD (A)
200
0
1
2
3
1500
1000
500
500
2
3
0
4
0
1
2
3
8027 G13
1500
1000
500
1
2
LOAD (A)
0
1
3
4
8027 G16
2
LOAD (A)
3
8027 G15
15.50
36VIN
48VIN
60VIN
15.00
2500
2000
1500
1000
0
14.50
14.00
13.50
13.00
36VIN
24VIN
12VIN
12.50
0
1
4
Bias Current vs Load,
VOUT = 2.5V
500
0
1000
0
4
BIAS CURRENT (mA)
2000
0
1500
Input Current vs Load,
VOUT = 24V
3000
INPUT CURRENT (mA)
INPUT CURRENT (mA)
2500
2000
8027 G14
3500
24VIN
36VIN
48VIN
60VIN
3000
24VIN
36VIN
48VIN
60VIN
LOAD (A)
Input Current vs Load,
VOUT = 18V
4
3
500
LOAD (A)
3500
2
LOAD (A)
Input Current vs Load,
VOUT = 15V
2500
INPUT CURRENT (mA)
INPUT CURRENT (mA)
INPUT CURRENT (mA)
1000
1
1
8027 G12
3000
24VIN
36VIN
48VIN
60VIN
2000
1500
0
0
8027 G11
2500
2000
0
0
4
Input Current vs Load,
VOUT = 12V
12VIN
24VIN
36VIN
48VIN
60VIN
2500
600
LOAD (A)
Input Current vs Load,
VOUT = 8V
3000
800
400
8027 G10
3500
12VIN
24VIN
36VIN
48VIN
60VIN
1800
1000
500
1
2000
1500
500
0
Input Current vs Load,
VOUT = 5V
5VIN
12VIN
24VIN
36VIN
48VIN
60VIN
3000
INPUT CURRENT (mA)
2500
INPUT CURRENT (mA)
Input Current vs Load,
VOUT = 3.3V
INPUT CURRENT (mA)
Input Current vs Load,
VOUT = 2.5V
2
LOAD (A)
3
4
12.00
0
1
2
3
4
LOAD (A)
8027 G17
8027 G18
8027fb
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LTM8027
Typical Performance Characteristics (TA = 25°C unless otherwise noted)
Bias Current vs Load,
VOUT = 3.3V
Bias Current vs Load,
VOUT = 5V
18.0
25.5
16.5
16.0
15.5
15.0
48VIN
36VIN
24VIN
12VIN
14.5
0
1
2
LOAD (A)
15.0
14.5
14.0
48VIN
36VIN
24VIN
12VIN
13.5
13.0
4
3
0
1
2
29.0
37
28.0
27.5
27.0
26.5
26.0
48VIN
36VIN
24VIN
25.5
1
42
34
33
32
41
40
39
38
37
48VIN
36VIN
24VIN
0
1
2
3
48VIN
36VIN
36
35
4
0
1
VIN (V)
34
48VIN
36VIN
3
4
LOAD (A)
8027 G25
6.0
10.0
5.9
9.8
5.8
9.6
5.7
9.4
5.6
9.2
5.5
5.4
9.0
8.8
5.3
8.6
5.2
8.4
5.1
8.2
5.0
0
1
2
LOAD (A)
4
Minimum VIN vs Load,
VOUT = 8V
VIN (V)
42
36
3
8027 G24
Minimum VIN vs Load,
VOUT = 5V
38
2
LOAD (A)
8027 G23
44
4
8027 G21
LOAD (A)
40
3
43
35
30
4
3
2
44
31
46
BIAS CURRENT (mA)
0
Bias Current vs Load,
VOUT = 18V
36
Bias Current vs Load,
VOUT = 24V
2
22.0
4
LOAD (A)
8027 G22
1
48VIN
36VIN
24VIN
45
LOAD (A)
0
23.0
BIAS CURRENT (mA)
BIAS CURRENT (mA)
BIAS CURRENT (mA)
28.5
32
23.5
Bias Current vs Load,
VOUT = 15V
38
2
24.0
8027 G20
29.5
1
24.5
LOAD (A)
Bias Current vs Load,
VOUT = 12V
0
25.0
22.5
3
8027 G19
25.0
BIAS CURRENT (mA)
15.5
17.0
BIAS CURRENT (mA)
BIAS CURRENT (mA)
26.0
16.0
17.5
14.0
Bias Current vs Load,
VOUT = 8V
3
4
8027 G26
8.0
0
1
2
LOAD (A)
3
4
8027 G27
8027fb
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LTM8027
Typical Performance Characteristics (TA = 25°C unless otherwise noted)
Minimum VIN vs Load,
VOUT = 15V
19.0
15.5
18.5
15.0
18.0
14.5
17.5
14.0
16.5
13.0
16.0
12.5
15.5
0
1
2
3
15.0
4
24
23
22
17.0
13.5
12.0
Minimum VIN vs Load,
VOUT = 18V
VIN (V)
16.0
VIN (V)
VIN (V)
Minimum VIN vs Load,
VOUT = 12V
20
19
0
2
1
3
0
1
3
35
30
28
25
26
20
VIN (V)
30
Minimum VIN vs VOUT,
IOUT = 4A
Minimum VIN vs Load,
VOUT = –3.3V
9
8
7
6
15
22
10
20
5
18
0
4
8027 G30
VIN (V)
Minimum VIN vs Load,
VOUT = 24V
24
2
LOAD (A)
8027 G29
8027 G28
VIN (V)
18
4
LOAD (A)
LOAD (A)
32
21
5
4
3
2
0
1
2
3
4
1
0
5
10
LOAD (A)
15
20
1
3
30
10
25
8
20
Minimum VIN vs Load,
VOUT = –8V
Minimum VIN vs Load,
VOUT = –12V
50
45
40
35
15
4
10
2
5
0
0
4
8027 G33
VIN (V)
Minimum VIN vs Load,
VOUT = –5V
6
2
LOAD (A)
8027 G32
VIN (V)
VIN (V)
0
VOUT (V)
8027 G31
12
0
25
30
25
20
15
10
5
0
1
2
LOAD (A)
3
4
8027 G34
0
1
2
LOAD (A)
3
4
8027 G35
0
0
1
2
LOAD (A)
3
4
8027 G36
8027fb
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LTM8027
Typical Performance Characteristics (TA = 25°C unless otherwise noted)
42
45
36VIN
24VIN
12VIN
5VIN
32
27
22
17
12
50
60VIN
48VIN
36VIN
24VIN
12VIN
5VIN
40
TEMPERATURE RISE (°C)
37
TEMPERATURE RISE (°C)
Temperature Rise vs Load,
VOUT = 3.3V
35
30
25
20
15
10
30
25
20
15
10
5
2
0
0
2
3
4
0
1
LOAD (A)
2
4
3
80
50
40
30
20
10
0
90
60VIN
48VIN
36VIN
24VIN
16VIN
70
60
40
30
20
10
0
1
2
3
4
0
1
2
0
2
1
50
40
30
20
10
3
4
8027 G42
Temperature Rise vs Load,
VOUT = 24V
60VIN
48VIN
36VIN
90
TEMPERATURE RISE (°C)
TEMPERATURE RISE (°C)
20
LOAD (A)
100
60
0
30
8027 G41
60VIN
48VIN
36VIN
26VIN
80
40
LOAD (A)
Temperature Rise vs Load,
VOUT = 18V
70
50
0
4
3
8027 G40
90
70
60
10
LOAD (A)
100
60VIN
48VIN
36VIN
24VIN
20.5VIN
80
50
0
4
Temperature Rise vs Load,
VOUT = 15V
TEMPERATURE RISE (°C)
60
3
8027 G39
Temperature Rise vs Load,
VOUT = 12V
Temperature Rise vs Load,
VOUT = 8V
60VIN
48VIN
36VIN
24VIN
12VIN
2
LOAD (A)
8027 G38
TEMPERATURE RISE (°C)
70
1
0
LOAD (A)
8027 G37
TEMPERATURE RISE (°C)
40
5
1
60VIN
48VIN
36VIN
24VIN
12VIN
35
7
0
Temperature Rise vs Load,
VOUT = 5V
45
TEMPERATURE RISE (°C)
Temperature Rise vs Load,
VOUT = 2.5V
80
70
60
50
40
30
20
10
0
1
2
LOAD (A)
3
4
8027 G43
0
0
1
2
LOAD (A)
3
4
8027 G44
8027fb
8
LTM8027
Pin Functions
VIN (Bank 3): The VIN pins supply current to the LTM8027’s
internal regulator and to the internal power switch. These
pins must be locally bypassed with an external, low ESR
capacitor (see Table 2).
VOUT (Bank 1): Power Output Pins. Apply the output filter
capacitor and the output load between these and the GND
pins.
AUX (Pin A7): Low Current Voltage Source for BIAS1
and BIAS2. In many designs, the BIAS pin is connected
to VOUT by way of the AUX pin. The AUX pin is internally
connected to VOUT and is placed near the BIAS pins to ease
printed circuit board routing. Although this pin is internally
connected to VOUT, do NOT connect this pin to the load. If
this pin is not tied to BIAS1 and BIAS2, leave it floating.
BIAS1 (Pin A6): The BIAS1 pin connects to the internal
power bus. Connect to a power source greater than 8.5V.
If the output is greater than 8.5V, connect it to this pin. If
the output voltage is less, connect this to a voltage source
between 8.5V and 15V.
BIAS2 (Pin A3): Internal Biasing Power. Connect to AUX
(if 24V or less) or a voltage source above 3V. Do not leave
BIAS2 floating.
RUN (Pin A4): Tie the RUN pin to ground to shut down the
LTM8027. Tie to 1.4V or more for normal operation. The
RUN pin is internally clamped to 5V, so when it is pulled
up, be sure to use a pull-up resistor that limits the current in to the RUN pin to less than 1mA. If the shutdown
feature is not used, tie this pin to the VIN pin through a
pull-up resistor.
GND (Bank 2): Tie these GND pins to a local ground plane
below the LTM8027 and the circuit components.
RT (Pin B1): The RT pin is used to program the switching
frequency of the LTM8027 by connecting a resistor from
this pin to ground. The Applications Information section of
the data sheet includes a table to determine the resistance
value based on the desired switching frequency. Minimize
capacitance at this pin.
SYNC (Pin C1): The SYNC pin provides an external clock
input for synchronization of the internal oscillator. The RT
resistor should be set such that the internal oscillator frequency is 10% to 25% below the external clock frequency.
This external clock frequency must be between 100kHz and
500kHz. If unused, the SYNC pin is connected to GND. For
more information see Oscillator Sync in the Application
Information section of this data sheet.
ADJ (Pin A2): The LTM8027 regulates its ADJ pin to 1.23V.
Connect the adjust resistor from this pin to ground. The
value of RADJ is given by the equation:
RADJ = 613.77/(VOUT – 1.23)
where RADJ is in kΩ.
SS (Pin A5): The soft-start pin is used to program the
supply soft-start function. Use the following formula to
calculate CSS for a given output voltage slew rate:
CSS = 2µA(tSS/1.231V)
The pin should be left unconnected when not using the
soft-start function.
8027fb
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LTM8027
Block Diagram
VIN
VOUT
6.8µH
499k
4.7pF
2.2µF
RUN
SS
INTERNAL
CONNECTION
TO VOUT
CURRENT
MODE
CONTROLLER
SYNC
VIN
GND
INTERNAL
LINEAR
REGULATOR
RT
AUX
BIAS1
INTVCC
BIAS2
ADJ
8027 BD
Operation
The LTM8027 is a standalone nonisolated step-down
switching DC/DC power supply with an input voltage
range of 4.5V to 60V that can deliver up to 4A of output
current. This module provides a precisely regulated output
voltage up to 24V, programmable via one external resistor.
Given that the LTM8027 is a step-down converter, make
sure that the input voltage is high enough to support the
desired output voltage and load current. A simplified block
diagram is given above. The LTM8027 contains a current
mode controller, power switching element, power inductor, power MOSFETs and a modest amount of input and
output capacitance.
The LTM8027 is a fixed frequency PWM regulator. The
switching frequency is set by simply connecting the appropriate resistor from the RT pin to GND.
A linear regulator provides internal power (shown as
INTVCC on the Block Diagram) to the control circuitry.
The bias regulator normally draws power from the VIN
pin, but if the BIAS1 pin is connected to an external voltage higher than 8.5V, bias power will be drawn from the
external source (typically the regulated output voltage).
This improves efficiency. The RUN pin is used to enable
or place the LTM8027 in shutdown, disconnecting the
output and reducing the input current to less than 9µA.
8027fb
10
LTM8027
Applications Information
For most applications, the design process is straight
forward, summarized as follows:
1. Look at Table 2 and find the row that has the desired
input range and output voltage.
2. Apply the recommended CIN, COUT, RADJ and RT values.
3. Connect the BIAS pins as indicated.
While these component and connection combinations have
been tested for proper operation, it is incumbent upon the
user to verify proper operation over the intended system’s
line, load and environmental conditions.
Capacitor Selection Considerations
The CIN and COUT capacitor values in Table 2 are the
minimum recommended values for the associated operating conditions. Applying capacitor values below those
indicated in Table 2 is not recommended, and may result
in undesirable operation. Using larger values is generally
acceptable, and can yield improved dynamic response, if
it is necessary. Again, it is incumbent upon the user to
verify proper operation over the intended system’s line,
load and environmental conditions.
Ceramic capacitors are small, robust and have very low
ESR. However, not all ceramic capacitors are suitable.
X5R and X7R types are stable over temperature and applied voltage and give dependable service. Other types,
including Y5V and Z5U have very large temperature and
voltage coefficients of capacitance. In an application circuit they may have only a small fraction of their nominal
capacitance resulting in much higher output voltage ripple
than expected.
A final precaution regarding ceramic capacitors concerns
the maximum input voltage rating of the LTM8027. A
ceramic input capacitor combined with trace or cable
inductance forms a high Q (under damped) tank circuit.
If the LTM8027 circuit is plugged into a live supply, the
input voltage can ring to twice its nominal value, possibly exceeding the device’s rating. This situation is easily
avoided; see the Hot-Plugging Safely section.
Input Power Requirements
The LTM8027 is biased using an internal linear regulator
to generate operational voltages from the VIN pin. Virtually
all of the circuitry in the LTM8027 is biased via this internal
linear regulator output (INTVCC on the Block Diagram).
This pin is internally decoupled with a low ESR capacitor
to GND. The INTVCC regulator generates an 8V output
provided there is ample voltage on the VIN pin. The INTVCC
regulator has approximately 1V of dropout, and will follow
the VIN pin with voltages below the dropout threshold.
The LTM8027 has a typical start-up requirement of VIN >
7.5V. This assures that the onboard regulator has ample
headroom to bring the internal regulator (INTVCC) above
its UVLO threshold. The INTVCC regulator can only source
current, so forcing the BIAS1 pin above 8.5V allows use
of externally derived power for the IC. This effectively
shuts down the internal linear regulator and reduces
power dissipation within the LTM8027. Using the onboard
regulator for start-up, then applying power to BIAS1 from
the converter output or external supply maximizes conversion efficiencies and is a common practice. If IBIAS1
is maintained above 6.5V using an external source, the
LTM8027 can continue to operate with VIN as low as 4.5V.
BIAS Power
The internal circuitry of the LTM8027 is powered by the
INTVCC bus, which is derived either from the afore mentioned internal linear regulator or the BIAS1 pin, if it is
greater than 8.5V. Since the internal linear regulator is by
nature dissipative, deriving INTVCC from an external source
through the BIAS pins reduces the power lost within the
LTM8027 and can increase overall system efficiency.
8027fb
11
LTM8027
Applications Information
PINTVCC = (VIN – 8) • IINTVCC
or only 60mW. This has a small but probably acceptable
effect on the operating temperature of the LTM8027.
If the input rises to 60V, however, the power dissipation is
a lot higher, over 780mW. This can cause unnecessarily
high junction temperatures if the INTVCC regulator must
dissipate this amount of power for very long.
Connect BIAS2 to AUX (if 24V or less) or a voltage source
above 3V.
Soft-Start
The soft-start function controls the slew rate of the power
supply output voltage during start-up. A controlled output
voltage ramp minimizes output voltage overshoot, reduces
inrush current from the VIN supply, and facilitates supply
sequencing. A capacitor connected from the SS pin to GND
programs the slew rate. The capacitor is charged from an
internal 2µA current source producing a ramped voltage
that overrides the command reference to the controller,
resulting in a smooth output voltage ramp. The soft-start
circuit is disabled once the SS pin voltage has been charged
to 200mV above the internal reference of 1.231V.
During a VIN UVLO, RUN event, or undervoltage on internal
bias, the SS pin voltage is discharged with a 50µA current.
Therefore, the value of the SS capacitor determines how
long one of these events must be in order to completely
discharge the soft-start capacitor. In the case of an output
overload or short circuit, the SS pin voltage is clamped to
a diode drop above the ADJ pin. Once the short has been
removed the VADJ pin voltage starts to recover. The softstart circuit takes control of the output voltage slew rate
once the VADJ pin voltage has exceeded the slowly ramp-
ing SS pin voltage, reducing the output voltage overshoot
during a short-circuit recovery.
The desired soft-start time (tSS) is programmed via the
CSS capacitor as follows:
CSS =
2µA • tSS
1.231V
The amount of time in which the power supply must be
under a VIN, internal regulator (INTVCC) or VSHDN UVLO
fault condition (tFAULT) before the SS pin voltage enters
its active region is approximated by the following formula:
CSS • 0.65V
50µA
tFAULT =
Operating Frequency Trade-offs
The LTM8027 uses a constant frequency architecture that
can be programmed over a 100kHz to 500kHz range with
a single resistor from the RT pin to ground. The nominal
voltage on the RT pin is 1V and the current that flows from
this pin is used to charge an internal oscillator capacitor.
The value of RT for a given operating frequency can be
chosen from Figure 1 or Table 1.
600
500
FREQUENCY (kHz)
For example, suppose the LTM8027 needs to provide 5V
from an input voltage source that is nominally 12V. From
Table 2, the recommended RT value is 162k, which corresponds to an operating frequency of 210kHz. From the
graphs in the Typical Performance Characteristics, the
typical internal regulator (INTVCC) current at 12VIN and
210kHz is 15mA. The power dissipated by the internal
linear regulator at 12VIN is given by the equation:
400
300
200
100
0
0
50
100
RT (kΩ)
150
200
8027 F01
Figure 1. Timing Resistor (RT) Value
8027fb
12
LTM8027
Applications Information
Table 1 lists typical resistor values for common operating
frequencies.
Table 1. RT Resistor Values vs Frequency
RT (kΩ)
fSW (kHz)
187
100
118
150
82.5
200
63.4k
250
48.7k
300
40.2k
350
31.6k
400
27.4k
450
23.7k
500
It is recommended that the user apply the RT value given
in Table 2 for the input and output operating condition.
System level or other considerations, however, may necessitate another operating frequency. While the LTM8027 is
flexible enough to accommodate a wide range of operating frequencies, a haphazardly chosen one may result
in undesirable operation under certain operating or fault
conditions. A frequency that is too high can damage the
LTM8027 if the output is overloaded or short-circuited. A
frequency that is too low can result in a final design that has
too much output ripple or too large of an output capacitor.
The maximum frequency (fMAX) at which the LTM8027
should be allowed to switch and the minimum frequency
set resistor value that should be used for a given set of
input and output operating condition is given in Table 2
as RT(MIN). There are additional conditions that must be
satisfied if the synchronization function is used. Please
refer to the Synchronization section for details.
Output Voltage Programming
The LTM8027 regulates its ADJ pin to 1.23V. Connect the
adjust resistor from this pin to ground. The value of RADJ
is given by the equation RADJ = 613.77/(VOUT – 1.23),
where RADJ is in kΩ.
RUN Control
The LTM8027 RUN pin uses a reference threshold of 1.4V.
This precision threshold allows use of the RUN pin for both
logic-level controlled applications and analog monitoring applications such as power supply sequencing. The
LTM8027 operational status is primarily controlled by a
UVLO circuit on internal power source. When the LTM8027
is enabled via the RUN pin, only the internal regulator
(INTVCC) is enabled. Switching remains disabled until
the UVLO threshold is achieved at the BIAS1 pin, when
the remainder of the LTM8027 is enabled and switching
commences.
Because the LTM8027 high power converter is a power
transfer device, a voltage that is lower than expected on
the input supply could require currents that exceed the
sourcing capabilities of that supply, causing the system
to lock up in an undervoltage state. Input supply startup protection can be achieved by enabling the RUN pin
using a resistive divider from the VIN supply to ground.
Setting the divider output to 1.4V when that supply is at
an adequate voltage prevents an LTM8027 converter from
drawing large currents until the input supply is able to
provide the required power. 200mV of input hysteresis on
the RUN pin allows for about 15% of input supply droop
before disabling the converter.
Input UVLO and RUN
The RUN pin has a precision voltage threshold with hysteresis which can be used as an undervoltage lockout
threshold (UVLO) for the power supply. Undervoltage
lockout keeps the LTM8027 in shutdown until the supply
input voltage is above a certain voltage programmed by
the user. The hysteresis voltage prevents noise from falsely
tripping UVLO. Resistors are chosen by first selecting RB
(refer to Figure 2). Then:
 VIN(ON) 
RA = RB • 
– 1
 1.4V

where VIN(ON) is the input voltage at which the undervoltage lockout is disabled and the supply turns on.
8027fb
13
LTM8027
Applications Information
VSUPPLY
RA
RUN PIN
RB
8027 F02
Figure 2. Undervoltage Lockout Resistive Divider
Example: Select RB = 49.9k, VIN(ON) = 14.5V (based upon
a 15V minimum input voltage)
 14.5V 
RA = 49.9k • 
– 1 = 464k
 1.4V

The VIN turn off voltage is 15% below turn on. In the
example the VIN(OFF) would be 12.3V. The shutdown function can be disabled by connecting the RUN pin to the VIN
pin through a large value pull-up resistor, (RPU). This pin
contains a low impedance clamp at 6V, so the RUN pin
will sink current from the RPU pull-up resistor:
V – 6V
IRUN = IN
RPU
Because this arrangement will clamp the RUN pin to 6V,
it will violate the 5V absolute maximum voltage rating of
the pin. This is permitted, however, as long as the absolute
maximum input current rating of 1mA is not exceeded.
Input RUN pin currents of <100µA are recommended: a
1M or greater pull-up resistor is typically used for this
configuration.
Hot-Plugging Safely
The small size, robustness and low impedance of ceramic
capacitors make them an attractive option for the input
bypass capacitor of LTM8027. However, these capacitors
can cause problems if the LTM8027 is plugged into a live
supply (see Linear Technology Application Note 88 for
a complete discussion). The low loss ceramic capacitor
combined with stray inductance in series with the power
source forms an under damped tank circuit, and the voltage at the VIN pin of the LTM8027 can ring to twice the
nominal input voltage, possibly exceeding the LTM8027’s
rating and damaging the part. If the input supply is poorly
controlled or the user will be plugging the LTM8027 into an
energized supply, the input network should be designed to
prevent this overshoot by introducing a damping element
into the path of current flow. This is often done by adding an inexpensive electrolytic bulk capacitor across the
input terminals of the LTM8027. The criteria for selecting
this capacitor is that the ESR is high enough to damp
the ringing, and the capacitance value is several times
larger than the LTM8027 ceramic input capacitor. The bulk
capacitor does not need to be located physically close to
the LTM8027; it should be located close to the application
board’s input connector, instead.
Synchronization
The oscillator can be synchronized to an external clock.
Choose the RT resistor such that the resultant frequency is
at least 10% below the desired synchronization frequency.
It is recommended that the SYNC pin be driven with a
square wave that has amplitude greater than 2.3V, pulse
width greater than 1µs and rise time less than 500ns. The
rising edge of the sync wave form triggers the discharge
of the internal oscillator capacitor.
PCB Layout
Most of the headaches associated with PCB layout have
been alleviated or even eliminated by the high level of
integration of the LTM8027. The LTM8027 is nevertheless a switching power supply, and care must be taken to
minimize EMI and ensure proper operation. Even with the
high level of integration, you may fail to achieve specified
operation with a haphazard or poor layout. See Figure 3
for a suggested layout.
8027fb
14
LTM8027
Applications Information
VOUT
COUT
COUT
GND
AUX
BIAS1
SS
RUN
CIN
BIAS2
VIN
RADJ
GND
RT
8027 F03
SYNC
Figure 3. Suggested Layout
Ensure that the grounding and heat sinking are acceptable.
A few rules to keep in mind are:
1. Place the RADJ and RT resistors as close as possible to
their respective pins.
2. Place the CIN capacitor as close as possible to the VIN
and GND connection of the LTM8027.
3. Place the COUT capacitor as close as possible to the
VOUT and GND connection of the LTM8027.
4. Place the CIN and COUT capacitors such that their
ground current flow directly adjacent to or underneath
the LTM8027.
5. Connect all of the GND connections to as large a copper
pour or plane area as possible on the top layer. Avoid
breaking the ground connection between the external
components and the LTM8027.
Use vias to connect the GND copper area to the board’s
internal ground planes. Liberally distribute these GND vias
to provide both a good ground connection and thermal
path to the internal planes of the printed circuit board. Pay
attention to the location and density of the thermal vias in
Figure 3. The LTM8027 can benefit from the heat sinking
afforded by vias that connect to internal GND planes at
these locations, due to their proximity to internal power
handling components. The optimum number of thermal
vias depends upon the printed circuit board design. For
example, a board might use very small via holes. It should
employ more thermal vias than a board that uses larger
holes.
Thermal Considerations
The LTM8027 output current may need to be derated if it
is required to operate in a high ambient temperature or
deliver a large amount of continuous power. The amount
of current derating is dependent upon the input voltage,
output power and ambient temperature. The temperature
rise curves given in the Typical Performance Characteristics section can be used as a guide. These curves were
generated by a LTM8027 mounted to a 58cm2 4-layer FR4
printed circuit board. Boards of other sizes and layer count
can exhibit different thermal behavior, so it is incumbent
upon the user to verify proper operation over the intended
system’s line, load and environmental operating conditions.
8027fb
15
LTM8027
Applications Information
The junction-to-air and junction-to-board thermal resistances given in the Pin Configuration diagram may also
be used to estimate the LTM8027 internal temperature.
These thermal coefficients are determined per JESD 51-9
(JEDEC standard, test boards for area array surface mount
package thermal measurements) through analysis and
physical correlation. Bear in mind that the actual thermal
resistance of the LTM8027 to the printed circuit board
depends upon the design of the circuit board.
The die temperature of the LTM8027 must be lower than
the maximum rating of 125°C, so care should be taken in
the layout of the circuit to ensure good heat sinking of the
LTM8027. The bulk of the heat flow out of the LTM8027
is through the bottom of the module and the LGA pads
into the printed circuit board. Consequently a poor printed
circuit board design can cause excessive heating, resulting in impaired performance or reliability. Please refer to
the PCB Layout section for printed circuit board design
suggestions.
Table 2. Recommended Component Values and Configuration
(TA = 25°C. See Typical Performance Characteristics for load Conditions)
VIN RANGE
(V)
VOUT
(V)
BIAS1
RADJ
(kΩ)
fOPTIMAL
(kHz)
4.5 to 60
3.3
7.5 to 60
5
2 × 4.7µF 2220 100V 5 × 100µF 1812 6.3V
8.5V to 15V
301
115
154
160
107
2 × 4.7µF 2220 100V 4 × 100µF 1210 6.3V
8.5V to 15V
162
210
75.0
230
68.2
10.5 to 60
8
2 × 4.7µF 2220 100V
4 × 47µF 1210 10V
8.5V to 15V
90.9
260
59.0
350
40.2
2 × 4.7µF 2220 100V
4 × 22µF 1210 16V
AUX
56.2
300
48.7
500
23.7
44.2
350
40.2
500
23.7
CIN
COUT
ROPTIMAL
(kΩ)
fMAX
(kHz)
RMAX
(kΩ)
16 to 60
12
20.5 to 60
15
2 × 4.7µF 2220 100V
4 × 22µF 1210 16V
AUX
26 to 60
18
2 × 4.7µF 2220 100V
4 × 10µF 1812 25V
8.5V to 15V
36.5
400
31.6
500
23.7
34 to 60
24
2 × 4.7µF 2220 100V
4 × 10µF 1812 25V
8.5V to 15V
26.7
430
28.7
500
23.7
4.5 to 40
2.5
2 × 10µF 2220 50V
5 × 100µF 1812 6.3V
8.5V to 15V
487
145
124
185
88.7
4.5 to 40
3.3
2 × 10µF 2220 50V
4 × 100µF 1812 6.3V
8.5V to 15V
301
165
102
240
64.9
7.5 to 40
5
2 × 10µF 2220 50V
4 × 100µF 1210 6.3V
8.5V to 15V
162
210
75.0
315
45.3
10.5 to 40
8
2 × 10µF 2220 50V
4 × 47µF 1210 10V
8.5V to 15V
90.9
260
59.0
500
23.7
16 to 40
12
2 × 10µF 2220 50V
4 × 22µF 1210 16V
AUX
56.2
300
48.7
500
23.7
20.5 to 40
15
1 × 10µF 2220 50V
4 × 22µF 1210 16V
AUX
44.2
350
40.2
500
23.7
26 to 40
18
1 × 10µF 2220 50V
4 × 10µF 1812 25V
8.5V to 15V
36.5
400
31.6
500
23.7
34 to 40
24
1 × 10µF 2220 50V
4 × 10µF 1812 25V
8.5V to 15V
26.7
430
28.7
500
23.7
4.5 to 56
–3.3
2 × 4.7µF 2220 100V 5 × 100µF 1812 6.3V 8.5V to 15V Above Output
301
115
154
155
115
4.5 to 55
–5
2 × 4.7µF 2220 100V 4 × 100µF 1210 6.3V 8.5V to 15V Above Output
162
190
90.9
230
68.2
10.5 to 52
–8
2 × 4.7µF 2220 100V
4 × 47µF 1210 10V
8.5V to 15V Above Output
90.9
260
59.0
350
40.2
16 to 48
–12
2 × 4.7µF 2220 100V
4 × 22µF 1210 16V
AUX
56.2
300
48.7
500
23.7
8027fb
16
LTM8027
Typical Applications
3.3V VOUT Step-Down Converter
VIN*
4.5V TO 40V
10µF
×2
VIN
1M
VOUT
3.3V
4A
VOUT
LTM8027
RUN
BIAS1
SS
BIAS2
100µF
×4
AUX
SYNC
RT
ADJ
GND
102k
9V
301k
*RUNNING VOLTAGE. SEE APPLICATIONS
INFORMATION FOR START-UP DETAILS
3845 TA02
5V VOUT Step-Down Converter
VIN
7.5V TO 60V
4.7µF
×2
VIN
1M
LTM8027
RUN
BIAS1
SS
BIAS2
9V
100µF
×4
AUX
SYNC
RT
75k
VOUT
5V
4A
VOUT
ADJ
GND
162k
3845 TA03
8027fb
17
LTM8027
TYPICAL Applications
18V VOUT Step-Down Converter
VIN
26V TO 60V
4.7µF
×2
VIN
1M
VOUT
18V
3A
4A SURGE
VOUT
LTM8027
RUN
BIAS1
SS
BIAS2
9V
10µF
×4
AUX
SYNC
RT
ADJ
GND
31.6k
36.5k
3845 TA05
–12V VOUT Positive-to-Negative Converter
VIN
20V TO 48V
4.7µF
×2
VIN
1M
VOUT
LTM8027
RUN
BIAS1
SS
BIAS2
RT
48.7k
22µF
×4
AUX
SYNC
ADJ
GND
56.2k
3845 TA07
SCHOTTKY
DIODE
OPTIONAL
VOUT
–12V
3A
Package Photograph
8027fb
18
4
2.540
SUGGESTED PCB LAYOUT
TOP VIEW
2.540
3.810
5.080
6.350
X
15
BSC
Y
DETAIL A
0.27 – 0.37
SUBSTRATE
eee S X Y
DETAIL B
0.635 ±0.025 SQ. 113x
aaa Z
3.95 – 4.05
MOLD
CAP
DETAIL B
4.22 – 4.42
6. THE TOTAL NUMBER OF PADS: 113
SYMBOL TOLERANCE
aaa
0.15
bbb
0.10
eee
0.05
5. PRIMARY DATUM -Z- IS SEATING PLANE
DETAILS OF PAD #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PAD #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
4
6.350
LAND DESIGNATION PER JESD MO-222, SPP-010
3
5.080
3.810
2.540
1.270
1.27
BSC
12.70
BSC
3
L
TRAY PIN 1
BEVEL
COMPONENT
PIN “A1”
PADS
SEE NOTES
2. ALL DIMENSIONS ARE IN MILLIMETERS
3.810
0.000
5.080
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
6.350
(Reference LTC DWG # 05-08-1756 Rev Ø)
Z
1.270
2.540
3.810
5.080
6.350
PACKAGE TOP VIEW
1.270
PAD 1
CORNER
15
BSC
0.000
aaa Z
1.270
// bbb Z
LGA Package
113-Lead (15mm × 15mm × 4.32mm)
K
J
G
F
E
D
C
B
LGA 113 0807 REV Ø
A
DETAIL A
PACKAGE IN TRAY LOADING ORIENTATION
LTMXXXXXX
µModule
PACKAGE BOTTOM VIEW
H
12.70
BSC
1
2
3
4
5
6
7
8
9
C(0.30)
PAD 1
10
11
LTM8027
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
Package Description
8027fb
19
LTM8027
Package Description
Pin Assignment Table
(Arranged by Pin Number)
PIN NAME
PIN NAME
PIN NAME
A1
GND
D6
GND
H5
GND
A2
ADJ
D7
GND
H6
GND
A3
BIAS2
D8
GND
H7
GND
A4
RUN
D9
GND
H8
GND
A5
SS
D10
GND
H9
VOUT
A6
BIAS1
D11
GND
H10
VOUT
A7
AUX
E1
GND
H11
VOUT
A8
GND
E2
GND
J1
VIN
A9
GND
E3
GND
J2
VIN
A10
GND
E4
GND
J3
VIN
A11
GND
E5
GND
J5
GND
B1
RT
E6
GND
J6
GND
B2
GND
E7
GND
J7
GND
B3
GND
E8
GND
J8
GND
B4
GND
E9
VOUT
J9
VOUT
B5
GND
E10
VOUT
J10
VOUT
B6
GND
E11
VOUT
J11
VOUT
B7
GND
F1
GND
K1
VIN
B8
GND
F2
GND
K2
VIN
B9
GND
F3
GND
K3
VIN
B10
GND
F4
GND
K5
GND
B11
GND
F5
GND
K6
GND
C1
SYNC
F6
GND
K7
GND
C2
GND
F7
GND
K8
GND
C3
GND
F8
GND
K9
VOUT
C4
GND
F9
VOUT
K10
VOUT
C5
GND
F10
VOUT
K11
VOUT
C6
GND
F11
VOUT
L1
VIN
C7
GND
G5
GND
L2
VIN
C8
GND
G6
GND
L3
VIN
C9
GND
G7
GND
L5
GND
C10
GND
G8
GND
L6
GND
C11
GND
G9
VOUT
L7
GND
D1
GND
G10
VOUT
L8
GND
D2
GND
G11
VOUT
L9
VOUT
D3
GND
H1
VIN
L10
VOUT
D4
GND
H2
VIN
L11
VOUT
D5
GND
H3
VIN
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20
LTM8027
Revision History
REV
DATE
DESCRIPTION
PAGE NUMBER
A
1/11
Changed Shutdown Current Supply to 9µA in Features.
1
Updated Absolute Maximum Ratings section.
2
Updated VBIAS1(MINOV) and Note 3 in Electrical Characteristics section.
3
Replaced graph 9.
4
Updated Pin Functions section.
B
9/11
9
Text edits to Applications Information.
11-16
Updated Typical Applications.
17, 18
Updated Related Parts.
22
Added (Note 3) notation to the Order Information section.
2
Updated minimum spec for VBIAS2.
3
Updated descriptions for AUX and BIAS2 in the Pin Functions section.
9
Updated text in the Input Power Requirements section.
11
Added text to end of the BIAS Power section.
12
8027fb
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
21
LTM8027
Typical Application
15V VOUT Step-Down Converter
VIN
20.5V TO 60V
4.7µF
×2
VIN
VOUT
15V
3.5A
4A SURGE
VOUT
1M
LTM8027
RUN
BIAS1
SS
BIAS2
RT
40.2k
22µF
×4
AUX
SYNC
ADJ
GND
44.2k
3845 TA04
Related Parts
PART NUMBER
DESCRIPTION
COMMENTS
LTM4600
10A DC/DC µModule Regulator
10A DC/DC Step-Down µModule Regulator, 15mm × 15mm × 2.8mm LGA
LTM4600HVMPV
Military Plastic 10A DC/DC µModule Regulator
–55°C to 125°C Operation, 15mm × 15mm × 2.8mm LGA
LTM4601/
LTM4601A
12A DC/DC µModule Regulator with PLL, Output
Tracking/Margining and Remote Sensing
Synchronizable, PolyPhase Operation, LTM4601-1 Version has no Remote
Sensing
LTM4602
20V, 6A DC/DC µModule Regulator
Pin Compatible with the LTM4600
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 ≤ 5V, 0.8V ≤ VOUT ≤ 5V, 9mm × 15mm × 2.3mm LGA
LTM4608A
8A Low VIN DC/DC µModule Regulator
2.7V ≤ VIN ≤ 5V, 0.6V ≤ VOUT ≤ 5V, 9mm × 15mm × 2.8mm LGA
LTM8020
200mA, 36V DC/DC µModule Regulator
Fixed 450kHz Frequency, 1.25V ≤ VOUT ≤ 5V, 6.25mm × 6.25mm × 2.32mm LGA
LTM8022
1A, 36V DC/DC µModule Regulator
Adjustable Frequency, 0.8V ≤ VOUT ≤ 5V, 9mm × 11.25mm × 2.82mm LGA,
Pin Compatible to the LTM8023
LTM8023
2A, 36V DC/DC µModule Regulator
Adjustable Frequency, 0.8V ≤ VOUT ≤ 5V, 9mm × 11.25mm × 2.82mm LGA,
Pin Compatible to the LTM8022
LTM8025
3A, 36V DC/DC µModule Regulator
0.8V ≤ VOUT ≤ 24V, 9mm × 15mm × 4.32mm LGA
8027fb
22 Linear Technology Corporation
LT 0911 REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2009