LTM4600HVMPV-PBF [Linear]
10A, 28VIN High Effi ciency DC/DC μModule; 10A , 28VIN高艾菲效率DC / DC微型模块型号: | LTM4600HVMPV-PBF |
厂家: | Linear |
描述: | 10A, 28VIN High Effi ciency DC/DC μModule |
文件: | 总24页 (文件大小:356K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
LTM4600HV
10A, 28V High Efficiency
IN
DC/DC µModule
U
DESCRIPTIO
FEATURES
The LTM®4600HV is a complete 10A, DC/DC step down
power supply with up to 28V input operation. Included
in the package are the switching controller, power FETs,
inductor, and all support components. Operating over
an input voltage range of 4.5V to 28V, the LTM4600HV
supports an output voltage range of 0.6V to 5V, set by a
single resistor. This high efficiency design delivers 10A
continuous current (12A peak), needing no heat sinks or
airflow to meet power specifications. Only bulk input and
output capacitors are needed to finish the design.
■
Complete Switch Mode Power Supply
■
Wide Input Voltage Range: 4.5V to 28V
■
10A DC, 12A Peak Output Current
Parallel Two μModule™ DC/DC Converters for 20A
■
Output Current
0.6V to 5V Output Voltage
■
■
1.5% Output Voltage Regulation
■
Ultrafast Transient Response
■
Current Mode Control
■
–55°C to 125°C Operating Temperature Range
(LTM4600HVMPV)
The low profile package (2.8mm) enables utilization of
unused space on the bottom of PC boards for high density
point of load regulation. High switching frequency and an
adaptiveon-timecurrentmodearchitectureenablesavery
fast transient response to line and load changes without
sacrificing stability. Fault protection features include
integrated overvoltage and short circuit protection with
a defeatable shutdown timer. A built-in soft-start timer is
adjustable with a small capacitor.
■
Pb-Free (e4) RoHS Compliant Package Gold-Pad
Finish
Up to 92% Efficiency
Programmable Soft-Start
Output Overvoltage Protection
■
■
■
■
Optional Short-Circuit Shutdown Timer
Small Footprint, Low Profile (15mm × 15mm ×
■
2.8mm) LGA Package
U
The LTM4600HV is packaged in a thermally enhanced,
compact (15mm × 15mm) and low profile (2.8mm) over-
molded Land Grid Array (LGA) package suitable for auto-
mated assembly by standard surface mount equipment.
The LTM4600HV is Pb-free and RoHS compliant.
APPLICATIO S
■
Telecom and Networking Equipment
■
Military and Avionics Systems
■
Industrial Equipment
■
Point of Load Regulation
, LTC, LT and LTM are registered trademarks of Linear Technology Corporation.
μModule is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
■
Servers
U
Efficiency vs Load Current with 24VIN (FCB = 0)
TYPICAL APPLICATIO
100
10A μModule Power Supply with 4.5V to 28V Input
90
V
OUT
80
70
60
50
V
IN
2.5V*
10A
V
V
OUT
IN
4.5V TO 28V
ABSMAX
C
C
OUT
IN
LTM4600HV
V
OSET
PGND SGND
31.6k
1.8V
2.5V
3.3V
OUT
OUT
OUT
4600hv TA01a
40
30
5V
OUT
*REVIEW DE-RATING CURVE AT
THE HIGHER INPUT VOLTAGE
2
4
8
0
10
6
LOAD CURRENT (A)
4600HV TA01b
4600hvfc
1
LTM4600HV
W W U W
ABSOLUTE AXI U RATI GS
PIN CONFIGURATION
(Note 1)
TOP VIEW
FCB, EXTV , PGOOD, RUN/SS, V .......... –0.3V to 6V
CC
OUT
V , SV , f ............................................ –0.3V to 28V
OSET
Operating Temperature Range (Note 2)
IN
V
IN ADJ
COMP
SGND
RUN/SS
FCB
V
IN
, COMP............................................. –0.3V to 2.7V
PGOOD
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
PGND
V
OUT
LGA PACKAGE
104-LEAD (15mm × 15mm × 2.8mm)
T
= 125°C, θ = 15°C/W, θ = 6°C/W,
JA JC
JMAX
θ
JA
DERIVED FROM 95mm × 76mm PCB WITH 4 LAYERS, WEIGHT = 1.7g
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTM4600HVEV#PBF
LTM4600HVIV#PBF
LTM4600HVMPV#PBF
LTM4600HVEV#TRPBF
LTM4600HVIV#TRPBF
LTM4600HVMPV#TRPBF LTM4600HVMPV
LTM4600HVEV
LTM4600HVIV
104-Lead (15mm × 15mm × 2.8mm)
104-Lead (15mm × 15mm × 2.8mm)
104-Lead (15mm × 15mm × 2.8mm)
–40°C to 85°C
–40°C to 85°C
–55°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, VIN = 12V. External CIN = 120μF, COUT = 200μF/Ceramic per typical
application (front page) configuration.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
●
●
V
Input DC Voltage
AbsMax 28V for Tolerance on 24V Inputs
4.5
28
V
IN(DC)
V
Output Voltage
FCB = 0V
V
OUT(DC)
V
IN
= 5V or 12V, V
= 1.5V, I = 0A
OUT
1.478
1.470
1.50
1.50
1.522
1.530
OUT
Input Specifications
V
Under Voltage Lockout Threshold
Input Inrush Current at Startup
I
I
= 0A
3.4
4
V
IN(UVLO)
OUT
I
= 0A, V
= 1.5V, FCB = 0
INRUSH(VIN)
OUT
OUT
V
= 5V
= 12V
= 24V
0.6
0.7
0.8
A
A
A
IN
IN
IN
V
V
I
Input Supply Bias Current
I
= 0A, EXTV Open
Q(VIN)
OUT CC
V
= 12V, V
= 12V, V
= 24V, V
= 24V, V
= 1.5V, FCB = 5V
1.2
42
mA
mA
mA
mA
μA
IN
IN
IN
IN
OUT
OUT
OUT
OUT
V
V
V
= 1.5V, FCB = 0V
= 2.5V, FCB = 5V
= 2.5V, FCB = 0V
1.8
36
Shutdown, RUN = 0.8V, V = 12V
35
75
IN
Min On Time
Min Off Time
100
400
ns
ns
I
Input Supply Current
V
IN
V
IN
V
IN
V
IN
= 12V, V
= 12V, V
= 1.5V, I
= 3.3V, I
= 10A
= 10A
1.52
3.13
3.64
1.6
A
A
A
S(VIN)
OUT
OUT
OUT
OUT
= 5V, V
= 1.5V, I
= 10A
OUT
OUT
= 24V to 3.3V at 10A, EXTV = 5V
A
CC
4600hvfc
2
LTM4600HV
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, VIN = 12V. External CIN = 120μF, COUT = 200μF/Ceramic per typical
application (front page) configuration.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Output Specifications
I
Output Continuous Current Range
V
V
= 12V, V
= 24V, V
= 1.5V
= 2.5V (Note 3)
0
0
10
10
A
A
OUTDC
IN
IN
OUT
OUT
(See Output Current Derating Curves for
Different V , V
and T )
A
IN OUT
●
●
ΔV
ΔV
Line Regulation Accuracy
V
V
= 1.5V. FCB = 0V, I
= 0A,
0.15
0.3
%
OUT(LINE)
OUT
IN
OUT
= 4.5V to 28V
V
OUT
Load Regulation Accuracy
V
OUT
= 1.5V. FCB = 0V, I
= 0A to 10A
OUT(LOAD)
OUT
V
V
= 5V
1
1.5
%
%
IN
IN
V
OUT
= 12V (Note 4)
V
Output Ripple Voltage
Output Ripple Voltage Frequency
Turn-On Time
V
= 12V, V
= 1.5V, FCB = 0V, I
= 0A
10
15
mV
P-P
OUT(AC)
IN
OUT
OUT
fs
FCB = 0V, I
= 5A, V = 12V, V = 1.5V
OUT
850
kHz
OUT
IN
t
V
= 1.5V, I
IN
IN
= 1A
START
OUT
OUT
V
= 12V
= 5V
0.5
0.7
ms
ms
V
ΔV
OUTLS
Voltage Drop for Dynamic Load Step
V
C
= 1.5V, Load Step: 0A/μs to 5A/μs
= 3 • 22μF 6.3V, 470μF 4V POSCAP,
36
mV
OUT
OUT
See Table 2
t
I
Settling Time for Dynamic Load Step V = 12V Load: 10% to 90% to 10% of Full Load
IN
25
μs
SETTLE
OUTPK
Output Current Limit
Output Voltage in Foldback
V
V
V
= 24V, V
= 12V, V
= 2.5V
= 1.5V
17
17
17
A
A
A
IN
IN
IN
OUT
OUT
OUT
= 5V, V
= 1.5V
Control Stage
●
V
OSET
Voltage at V
Pin
I
= 0A, V = 1.5V
OUT
0.591
0.594
0.6
0.6
0.609
0.606
V
V
OSET
OUT
V
RUN ON/OFF Threshold
0.8
–0.5
0.8
1.5
–1.2
1.8
100
16
2
–3
3
V
μA
μA
mV
mA
kΩ
V
RUN/SS
I
I
Soft-Start Charging Current
Soft-Start Discharging Current
V
V
= 0V
= 4V
RUN(C)/SS
RUN(D)/SS
RUN/SS
RUN/SS
V
– SV
EXTV = 0V, FCB = 0V
CC
IN
IN
I
Current into EXTV Pin
EXTV = 5V, FCB = 0V, V = 1.5V, I = 0A
EXTVCC
CC
CC
OUT
OUT
R
Resistor Between V
and V Pins
OSET
100
0.6
–1
FBHI
OUT
V
Forced Continuous Threshold
0.57
0.63
–2
FCB
I
Forced Continuous Pin Current
V
= 0.6V
μA
FCB
FCB
PGOOD Output
ΔV
ΔV
ΔV
PGOOD Upper Threshold
PGOOD Lower Threshold
PGOOD Hysteresis
V
V
V
Rising
7.5
10
–10
2
12.5
%
%
%
V
OSETH
OSET
OSET
Falling
–7.5
–12.5
OSETL
Returning
OSET(HYS)
OSET
V
PGL
PGOOD Low Voltage
I
= 5mA
0.15
0.4
PGOOD
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTM4600HVE 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 LTM46000HVMP
is guaranteed and tested over the –55°C to 125°C temperature range.
For output current derating at high temperature, please refer to Thermal
Considerations and Output Current Derating discussion.
Note 3: Refer to current de-rating curves and thermal application note.
Note 4: Test assumes current derating versus temperature.
4600hvfc
3
LTM4600HV
U W
TYPICAL PERFOR A CE CHARACTERISTICS (See Figure 21 for all curves)
Efficiency vs Load Current
with 24VIN (FCB = 0)
Efficiency vs Load Current
with 5VIN (FCB = 0)
Efficiency vs Load Current
with 12V(FCB = 0)
100
90
100
90
80
70
60
50
40
30
100
90
80
70
60
50
40
30
80
70
60
50
40
30
0.6V
1.2V
1.5V
2.5V
3.3V
OUT
OUT
OUT
OUT
OUT
1.8V
2.5V
3.3V
5V
0.6V
1.2V
1.5V
2.5V
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
2
4
8
0
10
8
10
2
4
8
6
0
2
4
6
0
10
6
LOAD CURRENT (A)
LOAD CURRENT (A)
LOAD CURRENT (A)
4600hv G03
4600hv G01
4600hv G02
Efficiency vs Load Current
with Different FCB Settings
1.2V Transient Response
1.5V Transient Response
90
80
70
60
50
40
30
20
FCB > 0.7V
V
= 50mV/DIV
OUT
FCB = GND
I
= 5A/DIV
OUT
4600hv G05
4600hv G06
25μs/DIV
1.2V AT 5A/μs LOAD STEP
C = 3 • 22μF 6.3V CERAMICS
OUT
470μF 4V SANYO POSCAP
C3 = 100pF
25μs/DIV
V
V
= 12V
OUT
IN
1.5V AT 5A/μs LOAD STEP
OUT
= 1.5V
C
= 3 • 22μF 6.3V CERAMICS
470μF 4V SANYO POSCAP
C3 = 100pF
0.1
10
1
LOAD CURRENT (A)
4600hv G04
1.8V Transient Response
2.5V Transient Response
3.3V Transient Response
4600hv G07
4600hv G08
4600hv G09
25μs/DIV
25μs/DIV
25μs/DIV
1.8V AT 5A/μs LOAD STEP
OUT
2.5V AT 5A/μs LOAD STEP
OUT
3.3V AT 5A/μs LOAD STEP
OUT
C
= 3 • 22μF 6.3V CERAMICS
470μF 4V SANYO POSCAP
C3 = 100pF
C
= 3 • 22μF 6.3V CERAMICS
470μF 4V SANYO POSCAP
C3 = 100pF
C
= 3 • 22μF 6.3V CERAMICS
470μF 4V SANYO POSCAP
C3 = 100pF
4600hvfc
4
LTM4600HV
U W
TYPICAL PERFOR A CE CHARACTERISTICS (See Figure 21 for all curves)
Start-Up, IOUT = 10A
(Resistive Load)
Start-Up, IOUT = 0A
V
V
OUT
(0.5V/DIV)
OUT
(0.5V/DIV)
I
I
IN
IN
(0.5A/DIV)
(0.5A/DIV)
4600hv G11
4600hv G10
200μs/DIV
200μs/DIV
V
V
C
= 12V
V
V
C
= 12V
IN
IN
= 1.5V
= 1.5V
OUT
OUT
= 200μF
= 200μF
OUT
OUT
NO EXTERNAL SOFT-START CAPACITOR
NO EXTERNAL SOFT-START CAPACITOR
Short-Circuit Protection,
I= 0A
Short-Circuit Protection,
I= 10A
VIN to VOUT Stepdown Ratio
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
f
= OPEN
5V
ADJ
V
V
OUT
(0.5V/DIV)
OUT
(0.5V/DIV)
I
I
IN
3.3V
IN
(0.2A/DIV)
(0.5A/DIV)
2.5V
1.8V
4600hv G12
4600hv G13
20μs/DIV
20μs/DIV
1.5V
1.2V
V
V
C
= 12V
OUT
OUT
V
V
C
= 12V
OUT
OUT
IN
IN
= 1.5V
= 1.5V
= 2× 200μF/X5R
= 2× 200μF/X5R
NO EXTERNAL SOFT-START CAPACITOR
NO EXTERNAL SOFT-START CAPACITOR
0.6V
10
20
24
0
5
15
(V)
V
IN
SEE FREQUENCY ADJUSTMENT DISCUSSION
FOR 12V TO 5V
AND 5V TO 3.3V
IN
OUT
IN OUT
CONVERSION
4600HV G14
Vvs Temperature
Start-Up Waveform, T= –55°C
0.610
0.605
0.600
0.595
4600HV G16
V
V
= 12V
400μs/DIV
IN
= 1.5V
OUT
= 10A
OUT
I
0.590
–55 –25
5
35
65
95
125
TEMPERATURE (°C)
4600HV G15
4600hvfc
5
LTM4600HV
U
U
U
PI FU CTIO S
(See Package Description for Pin Assignment)
V
(Bank 1): Power Input Pins. Apply input voltage
SGND (Pin D23): Signal Ground Pin. All small-signal
components should connect to this ground, which in turn
connects to PGND at one point.
IN
between these pins and GND pins. Recommend placing
input decoupling capacitance directly between V pins
and GND pins.
IN
RUN/SS (Pin F23): Run and Soft-Start Control. Forcing
this pin below 0.8V will shut down the power supply.
Inside the power module, there is a 1000pF capacitor
which provides approximately 0.7ms soft-start time with
200μF output capacitance. Additional soft-start time can
be achieved by adding additional capacitance between
the RUN/SS and SGND pins. The internal short-circuit
latchoff can be disabled by adding a resistor between this
f
(Pin A15): A 110k resistor from V to this pin sets
IN
ADJ
the one-shot timer current, thereby setting the switching
frequency.TheLTM4600HVswitchingfrequencyistypically
850kHz. An external resistor to ground can be selected to
reducetheone-shottimercurrent,thuslowertheswitching
frequency to accommodate a higher duty cycle step down
requirement. See the applications section.
pin and the V pin. This resistor must supply a minimum
IN
SV (PinA17):SupplyPinforInternalPWMController.Leave
this pin open or add additional decoupling capacitance.
IN
5μA pull up current.
FCB (Pin G23): Forced Continuous Input. Grounding this
pin enables forced continuous mode operation regardless
of load conditions. Tying this pin above 0.63V enables
discontinuousconductionmodetoachievehighefficiency
operation at light loads. There is an internal 4.75K resistor
between the FCB and SGND pins.
EXTV (Pin A19): External 5V supply pin for controller. If
CC
left open or grounded, the internal 5V linear regulator will
power the controller and MOSFET drivers. For high input
voltage applications, connecting this pin to an external
5V will reduce the power loss in the power module. The
EXTV voltage should never be higher than V .
CC
IN
PGOOD (Pin J23): Output Voltage Power Good Indicator.
When the output voltage is within 10% of the nominal
voltage, the PGOOD is open drain output. Otherwise, this
pin is pulled to ground.
V
(Pin A21): The Negative Input of The Error Amplifier.
OSET
Internally,thispinisconnectedtoV witha100kprecision
OUT
resistor.Differentoutputvoltagescanbeprogrammedwith
additional resistors between the V
and SGND pins.
OSET
PGND (Bank 2): Power ground pins for both input and
output returns.
COMP (Pin B23): 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 with 0.8V corresponding to zero
sense voltage (zero current).
V
OUT
(Bank 3): Power Output Pins. Apply output load
between these pins and GND pins. Recommend placing
High Frequency output decoupling capacitance directly
between these pins and GND pins.
TOP VIEW
2
3
4
5
6
7
16
17
18
19
A
C
E
1
20
21
22
23
24
B
D
F
COMP
SGND
RUN/SS
FCB
9
10
14
11
15
V
IN
8
BANK 1
13
12
25
32
G
J
26
33
27
34
28
35
29
36
30
37
31
38
H
K
PGOOD
48
59
39
50
61
40
51
62
41
52
63
42
53
64
43
54
65
44
55
66
45
56
67
46
57
68
47
58
69
49
60
71
PGND
BANK 2
L
M
N
70
73
84
95
74
85
96
75
86
97
76
87
98
77
88
99
78
89
79
90
80
91
81
92
72
83
94
82
93
P
R
T
V
OUT
BANK 3
100
101
102
103
104
1
3
5
7
9
11
13
15
17
19
21
23
2
4
6
8
10
12
14
16
18
20
22
4600hv PN01
4600hvfc
6
LTM4600HV
W
W
SI PLIFIED BLOCK DIAGRA
SV
IN
RUN/SS
LTM4600HV
V
V
, 4.5V TO 28V ABS MAX
IN
1000pF
C
1.5μF
IN
PGOOD
Q1
COMP
FCB
INT
COMP
, 2.5V/10A MAX
OUT
C
OUT
4.75k
15μF
6.3V
CONTROLLER
f
ADJ
PGND
Q2
10Ω
SGND
EXTV
CC
100k
0.5%
V
OSET
R6
31.6k
4600hv F01
Figure 1. Simplified LTM4600HV Block Diagram
U
W U
DECOUPLI G REQUIRE E TS
TA = 25°C, VIN = 12V. Use Figure 1 configuration.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
C
External Input Capacitor Requirement
I
= 10A, 2x 10μF 35V Ceramic
20
μF
IN
OUT
(V = 4.5V to 28V, V
= 2.5V)
Taiyo Yuden GDK316BJ106ML
IN
OUT
C
External Output Capacitor Requirement
(V = 4.5V to 28V, V = 2.5V)
I
= 10A, Refer to Table 2 in the
100
200
μF
OUT
OUT
Applications Information Section
IN
OUT
4600hvfc
7
LTM4600HV
U
OPERATIO
μModule Description
Q1 is turned off and bottom FET Q2 is turned on and held
on until the overvoltage condition clears.
TheLTM4600HVisastandalonenon-isolatedsynchronous
switching DC/DC power supply. It can deliver up to 10A of
DC output current with only bulk external input and output
capacitors. This module provides a precisely regulated
outputvoltageprogrammableviaoneexternalresistorfrom
Pulling the RUN/SS pin low forces the controller into its
shutdown state, turning off both Q1 and Q2. Releasing the
pin allows an internal 1.2μA current source to charge up
the softstart capacitor. When this voltage reaches 1.5V,
the controller turns on and begins switching.
0.6V to 5.0V . The input voltage range is 4.5V to 28V.
DC
DC
A simplified block diagram is shown in Figure 1 and the
At low load current the module works in continuous cur-
rent mode by default to achieve minimum output voltage
ripple. It can be programmed to operate in discontinuous
current mode for improved light load efficiency when the
FCB pin is pulled up above 0.8V and no higher than 6V.
The FCB pin has a 4.75k resistor to ground, so a resistor
typical application schematic is shown in Figure 21.
The LTM4600HV contains an integrated LTC constant
on-time current-mode regulator, ultra-low R
FETs
DS(ON)
with fast switching speed and integrated Schottky diode.
The typical switching frequency is 850kHz at full load.
With current mode control and internal feedback loop
compensation, the LTM4600HV module has sufficient
stability margins and good transient performance under a
wide range of operating conditions and with a wide range
of output capacitors, even all ceramic output capacitors
(X5R or X7R for extended temperature range).
to V can set the voltage on the FCB pin.
IN
When EXTV pin is grounded or open, an integrated 5V
CC
linear regulator powers the controller and MOSFET gate
drivers. If a minimum 4.7V external bias supply is ap-
plied on the EXTV pin, the internal regulator is turned
CC
off, and an internal switch connects EXTV to the gate
CC
Current mode control provides cycle-by-cycle fast current
limit. In addition, foldback current limiting is provided
in an over-current condition while V
the LTM4600HV has defeatable short circuit latch off.
Internal overvoltage and undervoltage comparators pull
the open-drain PGOOD output low if the output feedback
voltage exits a 10% window around the regulation point.
Furthermore, in an overvoltage condition, internal top FET
driver voltage. This eliminates the linear regulator power
loss with high input voltage, reducing the thermal stress
drops. Also,
on the controller. The maximum voltage on EXTV pin is
CC
OSET
6V. The EXTV voltage should never be higher than the
CC
V
IN
voltage. Also EXTV must be sequenced after V .
CC IN
Recommended for 24V operation to lower temperature
in the μModule.
4600hvfc
8
LTM4600HV
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The typical LTM4600HV application circuit is shown in
Figure 21. External component selection is primarily
determined by the maximum load current and output
voltage.
voltage is margined up. The output voltage is margined
down when Q
is on and Q is off. If the output
DOWN
UP
voltage V needs to be margined up/down by M%, the
O
resistor values of R and R
the following equations:
can be calculated from
UP
DOWN
Output Voltage Programming and Margining
(RSET RUP)•VO •(1+ M%)
(RSET RUP)+100kΩ
The PWM controller of the LTM4600HV has an internal
0.6V 1%referencevoltage.Asshownintheblockdiagram,
= 0.6V
a 100k/0.5% internal feedback resistor connects V
OUT
pin to
RSET •VO •(1– M%)
RSET + (100kΩ RDOWN
and V
pins. Adding a resistor R from V
OSET
SET
OSET
= 0.6V
)
SGND pin programs the output voltage:
100k +RSET
VO = 0.6V •
Input Capacitors
RSET
The LTM4600HV μModule should be connected to a low
ac-impedance DC source. High frequency, low ESR input
capacitors are required to be placed adjacent to the mod-
Table 1 shows the standard values of 1% R
for typical output voltages:
Table 1.
resistor
SET
ule. In Figure 21, the bulk input capacitor C is selected
IN
for its ability to handle the large RMS current into the
converter. For a buck converter, the switching duty-cycle
can be estimated as:
R
SET
Open 100
0.6 1.2
66.5
1.5
49.9
1.8
43.2
2
31.6
2.5
22.1
3.3
13.7
5
(kΩ)
V
(V)
O
VO
V
IN
Voltagemarginingisthedynamicadjustmentoftheoutput
voltage to its worst case operating range in production
testing to stress the load circuitry, verify control/protec-
tion functionality of the board and improve the system
reliability. Figure 2 shows how to implement margining
function with the LTM4600HV. In addition to the feedback
D =
Without considering the inductor current ripple, the RMS
current of the input capacitor can be estimated as:
IO(MAX)
η%
ICIN(RMS)
=
• D•(1−D)
resistor R , several external components are added.
SET
Turn off both transistor Q and Q
margining. When Q is on and Q
to disable the
UP
DOWN
In the above equation, η% is the estimated efficiency of
the power module. C1 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 only 2000 hours of life. This
makes it advisable to properly derate the input capacitor,
or choose a capacitor rated at a higher temperature than
required. Always contact the capacitor manufacturer for
derating requirements over temperature.
is off, the output
UP
DOWN
V
OUT
LTM4600HV
R
R
DOWN
Q
100k
DOWN
2N7002
V
OSET
PGND
SGND
R
SET
UP
In Figure 21, the input capacitors are used as high fre-
quency input decoupling capacitors. In a typical 10A
output application, 1-2 pieces of very low ESR X5R or
X7R (for extended temperature range), 10μF ceramic
capacitors are recommended. This decoupling capacitor
Q
UP
2N7002
4600hv F02
Figure 2. LTM4600HV Margining Implementation
4600hvfc
9
LTM4600HV
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should be placed directly adjacent the module input pins
in the PCB layout to minimize the trace inductance and
high frequency AC noise.
Soft-Start and Latchoff with the RUN/SS pin
The RUN/SS pin provides a means to shut down the
LTM4600HV as well as a timer for soft-start and over-
current latchoff. Pulling the RUN/SS pin below 0.8V puts
the LTM4600HV into a low quiescent current shutdown
Output Capacitors
The LTM4600HV is designed for low output voltage ripple.
(I ≤ 75μA). Releasing the pin allows an internal 1.2μA
Q
ThebulkoutputcapacitorsC ischosenwithlowenough
current source to charge up the timing capacitor C .
OUT
SS
effectiveseriesresistance(ESR)tomeettheoutputvoltage
Inside LTM4600HV, there is an internal 1000pF capaci-
ripple and transient requirements. C
can be low ESR
tor from RUN/SS pin to ground. If RUN/SS pin has an
OUT
tantalumcapacitor, lowESRpolymercapacitororceramic
capacitor (X5R or X7R). The typical capacitance is 200μF
if all ceramic output capacitors are used. The internally
optimized loop compensation provides sufficient stability
margin for all ceramic capacitors applications. Additional
output filtering may be required by the system designer,
if further reduction of output ripple or dynamic transient
spike is required. Refer to Table 2 for an output capaci-
tance matrix for each output voltage Droop, peak to peak
deviation and recovery time during a 5A/μs transient with
a specific output capacitance.
external capacitor C
starting is about:
to ground, the delay before
SS_EXT
1.5V
1.2μA
tDELAY
=
•(CSS_EXT +1000pF)
When the voltage on RUN/SS pin reaches 1.5V, the
LTM4600HV internal switches are operating with a clamp-
ing of the maximum output inductor current limited by the
RUN/SSpintotalsoft-startcapacitance.AstheRUN/SSpin
voltage rises to 3V, the soft-start clamping of the inductor
current is released.
Fault Conditions: Current Limit and Over current
Foldback
V to V
Stepdown Ratios
IN
OUT
There are restrictions in the maximum V to V
step
IN
OUT
The LTM4600HV has a current mode controller, which
inherently limits the cycle-by-cycle inductor current not
only in steady state operation, but also in transient.
down ratio that can be achieved for a given input voltage.
These contraints are shown in the Typical Performance
Characteristics curves labeled “V to V
Stepdown
IN
OUT
To further limit current in the event of an over load condi-
tion, the LTM4600HV provides foldback current limiting.
If the output voltage falls by more than 50%, then the
maximumoutputcurrentisprogressivelyloweredtoabout
one sixth of its full current limit value.
Ratio”. Note that additional thermal de-rating may apply.
See the Thermal Considerations and Output Current De-
Rating sections of this data sheet.
4600hvfc
10
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Table 2. Output Voltage Response Versus Component Matrix *(Refer to Figure 21)
TYPICAL MEASURED VALUES
C
OUT1
VENDORS
PART NUMBER
C
OUT2
VENDORS
PART NUMBER
TDK
C4532X5R0J107MZ (100μF,6.3V)
JMK432BJ107MU-T ( 100μF, 6.3V)
JMK316BJ226ML-T501 ( 22μF, 6.3V)
JMK316BJ226ML-T501 ( 22μF, 6.3V)
SANYO POSCAP
SANYO POSCAP
SANYO POSCAP
SANYO POSCAP
6TPE330MIL (330μF, 6.3V)
2R5TPE470M9 (470μF, 2.5V)
4TPE470MCL (470μF, 4V)
6TPD470M (470μF, 6.3V)
TAIYO YUDEN
TAIYO YUDEN
TAIYO YUDEN
V
C
C
C
C
C
C3
V
IN
(V)
5
5
5
5
12
12
12
12
5
5
5
5
12
12
12
12
5
5
5
5
12
12
12
12
5
5
5
5
12
12
12
12
24
24
7
7
7
7
12
12
12
12
24
15
20
DROOP
(mV)
PEAK TO PEAK
RECOVERY TIME
(μs)
LOAD STEP
(A/μs)
OUT
IN
IN
OUT1
OUT2
COMP
(V)
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.8
1.8
1.8
1.8
1.8
1.8
1.8
1.8
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.8
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
5
(CERAMIC)
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
2 × 10μF 35V
(BULK)
(CERAMIC)
(BULK)
470μF 4V
470μF 2.5V
330μF 6.3V
NONE
470μF 4V
470μF 2.5V
330μF 6.3V
NONE
470μF 4V
470μF 2.5V
330μF 6.3V
NONE
470μF 4V
470μF 2.5V
330μF 6.3V
NONE
470μF 4V
470μF 2.5V
330μF 6.3V
NONE
470μF 4V
470μF 2.5V
330μF 6.3V
NONE
470μF 4V
330μF 6.3V
470μF 4V
NONE
470μF 4V
470μF 4V
330μF 6.3V
NONE
(mV)
68
70
80
98
68
70
80
98
75
79
84
118
75
79
89
108
81
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
150μF 35V
3 × 22μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
1 × 100μF 6.3V
2 × 100μF 6.3V
3 × 22μF 6.3V
4 × 100μF 6.3V
1 × 100μF 6.3V
3 × 22μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
3 × 22μF 6.3V
2 × 100μF 6.3V
1 × 100μF 6.3V
3 × 22μF 6.3V
4 × 100μF 6.3V
1 × 100μF 6.3V
3 × 22μF 6.3V
2 × 100μF 6.3V
4 × 100μF 6.3V
3 × 22μF 6.3V
4 × 100μF 6.3V
4 × 100μF 6.3V
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
NONE 100pF
35
35
40
49
35
35
40
49
36
37
44
61
36
37
44
54
40
44
46
62
40
44
44
62
48
56
57
60
48
51
56
70
56
50
64
66
82
100
52
64
64
76
74
188
159
25
20
20
20
25
20
20
20
25
20
20
20
25
20
20
20
30
20
20
20
30
20
20
20
30
30
30
25
30
30
30
25
30
30
30
30
35
25
30
35
30
25
30
25
25
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
88
91
128
81
85
91
125
103
113
116
115
103
102
113
159
112
100
126
132
166
200
106
129
126
144
149
375
320
470μF 6.3V
470μF 6.3V
330μF 6.3V
470μF 4V
470μF 4V
NONE
470μF 4V
470μF 4V
330μF 6.3V
NONE
470μF 6.3V
NONE
NONE
5
*X7R is recommended for extended temperature range.
4600hvfc
11
LTM4600HV
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After the controller has been started and given adequate
to defeat latchoff. Any pull-up network must be able to
maintain RUN/SS above 4V maximum latchoff threshold
andovercomethe4μAmaximumdischargecurrent.Figure
time to charge up the output capacitor, C is used as a
SS
short-circuittimer.AftertheRUN/SSpinchargesabove4V,
if the output voltage falls below 75% of its regulated value,
then a short-circuit fault is assumed. A 1.8μA current then
3 shows a conceptual drawing of V
short circuit.
during startup and
RUN
beginsdischargingC . Ifthefaultconditionpersistsuntil
SS
V
the RUN/SS pin drops to 3.5V, then the controller turns
off both power MOSFETs, shuting down the converter
permanently. The RUN/SS pin must be actively pulled
down to ground in order to restart operation.
RUN/SS
4V
3.5V
3V
1.5V
The over-current protection timer requires the soft-start
SHORT-CIRCUIT
LATCH ARMED
timing capacitor C be made large enough to guarantee
SS
t
SHORT-CIRCUIT
LATCHOFF
that the output is in regulation by the time C has reached
SS
SOFT-START
OUTPUT
OVERLOAD
HAPPENS
CLAMPING
OF I RELEASED
the 4V threshold. In general, this will depend upon the size
of the output capacitance, output voltage and load current
characteristic. A minimum external soft-start capacitor
can be estimated from:
L
V
O
75%V
O
CSS_EXT +1000pF > COUT •VOUT (10–3[F /VS])
t
SWITCHING
STARTS
4600hv F03
Generally 0.1μF is more than sufficient.
Figure 3. RUN/SS Pin Voltage During Startup and
Short-Circuit Protection
Since the load current is already limited by the current
mode control and current foldback circuitry during a
shortcircuit,over-currentlatchoffoperationisNOTalways
needed or desired, especially the output has large amount
of capacitance or the load draw huge current during start
up. The latchoff feature can be overridden by a pull-up
currentgreaterthan5μAbutlessthan80μAtotheRUN/SS
V
V
RECOMMENDED VALUES FOR RUN/SS
IN
IN
V
R
RUN/SS
R
LTM4600HV
IN
RUN/SS
4.5V TO 5.5V
10.8V TO 13.8V
24V TO 28V
50k
150k
500k
RUN/SS
PGND SGND
4600hv F04
pin. The additional current prevents the discharge of C
SS
during a fault and also shortens the soft-start period. Us-
Figure 4. Defeat Short-Circuit Latchoff with a Pull-Up
Resistor to VIN
ing a resistor from RUN/SS pin to V is a simple solution
IN
4600hvfc
12
LTM4600HV
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Enable
EXTV Connection
CC
TheRUN/SSpincanbedrivenfromlogicasshowninFigure
5. This function allows the LTM4600HV to be turned on or
off remotely. The ON signal can also control the sequence
of the output voltage.
An internal low dropout regulator produces an internal 5V
supply that powers the control circuitry and FET drivers.
Therefore, if the system does not have a 5V power rail,
the LTM4600HV can be directly powered by V . The gate
IN
driver current through LDO is about 18mA. The internal
LDO power dissipation can be calculated as:
RUN/SS
P
= 18mA • (V – 5V)
IN
LDO_LOSS
LTM4600HV
ON
The LTM4600HV also provides an external gate driver
voltage pin EXTV . If there is a 5V rail in the system, it
PGND SGND
CC
2N7002
is recommended to connect EXTV pin to the external
4600hv F05
CC
5V rail. Whenever the EXTV pin is above 4.7V, the in-
CC
Figure 5. Enable Circuit with External Logic
ternal 5V LDO is shut off and an internal 50mA P-channel
switch connects the EXTV to internal 5V. Internal 5V is
CC
Output Voltage Tracking
supplied from EXTV until this pin drops below 4.5V. Do
CC
For the applications that require output voltage tracking,
several LTM4600HV modules can be programmed by the
power supply tracking controller such as the LTC2923.
Figure 6 shows a typical schematic with LTC2923. Coin-
not apply more than 6V to the EXTV pin and ensure that
CC
EXTV < V . The following list summaries the possible
CC
IN
connections for EXTV :
CC
1. EXTV grounded. Internal 5V LDO is always powered
CC
cident, ratiometric and offset tracking for V rising and
O
from the internal 5V regulator.
falling can be implemented with different sets of resistor
values. See the LTC2923 data sheet for more details.
2. EXTV connected to an external supply. Internal LDO
CC
is shut off. A high efficiency supply compatible with the
MOSFET gate drive requirements (typically 5V) can im-
prove overall efficiency. With this connection, it is always
Q1
V
IN
DC/DC
3.3V
5V
V
V
IN
required that the EXTV voltage can not be higher than
CC
V pin voltage.
IN
IN
R
V
GATE
RAMP
FB1
ONB
CC
LTM4600HV
V
3. EXTV is recommended for V > 20V
V
CC
IN
1.8V
ON
OSET
OUT
R
ONA
49.9k
LTC2923
Discontinuous Operation and FCB Pin
STATUS
SDO
RAMPBUF
TRACK1
TRACK2
V
V
IN
The FCB pin determines whether the internal bottom
MOSFET remains on when the current reverses. There is
an internal 4.75k pull-down resistor connecting this pin
to ground. The default light load operation mode is forced
continuous (PWM) current mode. This mode provides
minimum output voltage ripple.
R
R
TB1
TA1
IN
R
TB2
LTM4600HV
V
V
FB2
1.5V
OSET
OUT
GND
R
66.5k
TA2
4600hv F06
Figure 6. Output Voltage Tracking with the LTC2923 Controller
4600hvfc
13
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In the application where the light load efficiency is im-
portant, tying the FCB pin above 0.6V threshold enables
discontinuous operation where the bottom MOSFET turns
offwheninductorcurrentreverses.Therefore,theconduc-
tionlossisminimizedandlightloadefficiencyisimproved.
The penalty is that the controller may skip cycle and the
output voltage ripple increases at light load.
explanationoftheanalysisforthethermalmodels, andthe
derating curves. Tables 3 and 4 provide a summary of the
equivalent θ for the noted conditions. These equivalent
JA
θ
JA
parameters are correlated to the measure values, and
improvedwithair-flow.Thecasetemperatureismaintained
at 100°C or below for the derating curves. This allows for
4W maximum power dissipation in the total module with
top and bottom heatsinking, and 2W power dissipation
Paralleling Operation with Load Sharing
through the top of the module with an approximate θ
JC
between 6°C/W to 9°C/W. This equates to a total of 124°C
Two or more LTM4600HV modules can be paralleled to
provide higher than 10A output current. Figure 7 shows
the necessary interconnection between two paralleled
modules. The OPTI-LOOP™ current mode control en-
sures good current sharing among modules to balance
the thermal stress. The new feedback equation for two or
more LTM4600HVs in parallel is:
at the junction of the device.
Safety Considerations
The LTM4600HV modules do not provide isolation from
V to V . There is no internal fuse. If required, a slow
IN
OUT
blow fuse with a rating twice the maximum input current
should be provided to protect each unit from catastrophic
failure.
100k
+RSET
N
VOUT = 0.6V •
RSET
Layout Checklist/Example
where N is the number of LTM4600HVs in parallel.
The high integration of the LTM4600HV makes the PCB
board layout very simple and easy. However, to optimize
its electrical and thermal performance, some layout con-
siderations are still necessary.
V
V
V
V
OUT
IN
IN
OUT
(20A
)
MAX
LTM4600HV
PGND COMP
V
SGND
OSET
• Use large PCB copper areas for high current path, in-
R
SET
cluding V , PGND and V . It helps to minimize the
IN
OUT
PCB conduction loss and thermal stress
COMP
V
SGND
OSET
• Place high frequency ceramic input and output capaci-
V
LTM4600HV
V
OUT
IN
tors next to the V , PGND and V
pins to minimize
IN
OUT
PGND
high frequency noise
4600hv F07
• Place a dedicated power ground layer underneath
the unit
Figure 7. Parallel Two μModules with Load Sharing
• Tominimizetheviaconductionlossandreducemodule
thermal stress, use multiple vias for interconnection
between top layer and other power layers
Thermal Considerations and Output Current Derating
The power loss curves in Figures 8 and 15 can be used
in coordination with the load current derating curves in
Figures 9 to 14, and Figures 16 to 19 for calculating an
• Do not put vias directly on pad unless they are capped.
• Use a separated SGND ground copper area for com-
ponents connected to signal pins. Connect the SGND
to PGND underneath the unit
approximate θ for the module with various heatsink-
JA
ing methods. Thermal models are derived from several
temperature measurements at the bench, and thermal
modelinganalysis.ApplicationNote103providesadetailed
Figure 20 gives a good example of the recommended
OPTI-LOOP is a trademark of Linear Technology Corporation.
layout.
4600hvfc
14
LTM4600HV
U
W U U
APPLICATIO S I FOR ATIO
10
10
9
4.5
V
V
= 5V
V
V
= 5V
IN
OUT
V
= 1.5V
IN
OUT
OUT
= 1.5V
= 1.5V
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
9
8
7
6
5
4
18V LOSS
8
7
12V LOSS
6
5V LOSS
0 LFM
200 LFM
400 LFM
5
0 LFM
200 LFM
400 LFM
4
50
60
70
80
90
50
60
70
80
90
100
0
2
4
6
8
10
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
OUTPUT CURRENT (A)
4600hv F09
4600hv F10
4600hv F08
Figure 8. 1.5V Power Loss Curves
vs Load Current
Figure 9. No Heatsink
Figure 10. BGA Heatsink
10
9
8
7
6
5
4
3
2
1
0
10
9
10
9
V
V
= 18V
OUT
V
V
= 12V
V
= 12V
IN
IN
IN
OUT
= 1.5V
= 1.5V
V
= 1.5V
OUT
8
8
7
7
6
6
5
0 LFM
200 LFM
400 LFM
5
0 LFM
200 LFM
400 LFM
0 LFM
200 LFM
400 LFM
4
4
3
40
50
60
70
80
90
50 55 60 65 70 75 80 85 90
AMBIENT TEMPERATURE (°C)
4600hv F11
50
60
70
80
90
100
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4600hv F13
4600hv F12
Figure 13. No Heatsink
Figure 11. No Heatsink
Figure 12. BGA Heatsink
10
8
10
9
8
7
6
5
4
3
2
1
0
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
V
V
= 18V
V
V
= 12V
OUT
IN
OUT
IN
= 1.5V
= 3.3V
6
24V LOSS
4
12V LOSS
2
0 LFM
200 LFM
400 LFM
0 LFM
200 LFM
400 LFM
0
50
60
70
80
90
100
40
50
60
70
80
90
0
2
4
6
8
10
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
OUTPUT CURRENT (A)
4600hv F14
4600hv F16
4600hv F15
Figure 14. BGA Heatsink
Figure 16. No Heatsink
Figure 15. 3.3V Power Loss
Curves vs Load Current
4600hvfc
15
LTM4600HV
U
W U U
APPLICATIO S I FOR ATIO
10
9
10
8
10
9
0 LFM
200 LFM
400 LFM
V
V
= 12V
V
V
= 24V
IN
OUT
IN
OUT
= 3.3V
= 3.3V TEMPERATURE
DE-RATING
8
8
6
7
7
4
6
6
2
5
0 LFM
200 LFM
400 LFM
0 LFM
200 LFM
400 LFM
5
V
V
= 24V
OUT
DE-RATING
IN
= 3.3V TEMPERATURE
4
0
4
40
50
60
70
80
90
100
50
60
70
80
90
50
60
70
80
90
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
AMBIENT TEMPERATURE (°C)
4600hv F17
4600hv F18.eps
4600hv F19.eps
Figure 17. BGA Heatsink
Figure 18. No Heatsink
Figure 19. BGA Heatsink
Table 3. 1.5V Output
DERATING CURVE
Figures 9, 11, 13
Figures 9, 11, 13
Figures 9, 11, 13
Figures 10, 12, 14
Figures 10, 12, 14
Figures 10, 12, 14
V
(V)
POWER LOSS CURVE
Figure 8
AIR FLOW (LFM)
HEATSINK
None
θ
JA
(°C/W)
IN
5, 12, 18
5, 12, 18
5, 12, 18
5, 12, 18
5, 12, 18
5, 12, 18
0
15.2
14
Figure 8
200
400
0
None
Figure 8
None
12
Figure 8
BGA Heatsink
BGA Heatsink
BGA Heatsink
13.9
11.3
10.25
Figure 8
200
400
Figure 8
Table 4. 3.3V Output
DERATING CURVE
Figures 16, 18
V
(V)
POWER LOSS CURVE
Figure 15
AIR FLOW (LFM)
HEATSINK
None
θ
(°C/W)
JA
IN
12, 24
12, 24
12, 24
12, 24
12, 24
12, 24
0
15.2
14.6
13.4
13.9
11.1
10.5
Figures 16, 18
Figure 15
200
400
0
None
Figures 16, 18
Figure 15
None
Figures 17, 19
Figure 15
BGA Heatsink
BGA Heatsink
BGA Heatsink
Figures 17, 19
Figure 15
200
400
Figures 17, 19
Figure 15
4600hvfc
16
LTM4600HV
U
W U U
APPLICATIO S I FOR ATIO
V
t
IN
ON
(DC) DUTY CYCLE =
t
s
t
ON
V
OUT
DC =
=
t
V
s
IN
DC
FREQ =
t
ON
t
t
ON
C
OFF
IN
4602 F25
PERIOD t
s
The LTM4600HV has a minimum (t ) on time of 100
PGND
ON
nanoseconds and a minimum (t ) off time of 400
OFF
nanoseconds. The 2.4V clamp on the ramp threshold as
V
a function of V
will cause the switching frequency to
OUT
OUT
4600hv F20
increasebytheratioofV /2.4Vfor3.3Vand5Voutputs.
OUT
LOAD
This is due to the fact the on time will not increase as V
OUT
TOP LAYER
increases past 2.4V. Therefore, if the nominal switch-
ing frequency is 850kHz, then the switching frequency
will increase to ~1.2MHz for 3.3V, and ~1.7MHz for 5V
Figure 20. Recommended PCB Layout
LTM4600HV Frequency Adjustment
outputs due to Frequency = (DC/t ) When the switching
ON
frequency increases to 1.2MHz, then the time period t is
TheLTM4600HVisdesignedtotypicallyoperateat850kHz
across most input and output conditions. The control ar-
chitectureisconstantontimevalleymodecurrentcontrol.
S
reducedto~833nanosecondsandat1.7MHztheswitching
period reduces to ~588 nanoseconds. When higher duty
cycle conversions like 5V to 3.3V and 12V to 5V need to
be accommodated, then the switching frequency can be
lowered to alleviate the violation of the 400ns minimum
The f
pin is typically left open or decoupled with an
ADJ
optional 1000pF capacitor. The switching frequency has
beenoptimizedtomaintainconstantoutputrippleoverthe
operatingconditions.Theequationsforsettingtheoperat-
ing frequency are set around a programmable constant on
time.Thisontimeisdevelopedbyaprogrammablecurrent
into an on board 10pF capacitor that establishes a ramp
that is compared to a voltage threshold equal to the output
off time. Since the total switching period is t = t + t
,
S
ON OFF
t
will be below the 400ns minimum off time. A resistor
OFF
from the f
pin to ground can shunt current away from
ADJ
the on time generator, thus allowing for a longer on time
and a lower switching frequency. 12V to 5V and 5V to
3.3V derivations are explained in the data sheet to lower
switching frequency and accommodate these step-down
conversions.
voltage up to a 2.4V clamp. This I current is equal to:
ON
I
ON
= (V – 0.7V)/110k, with the 110k onboard resistor
IN
IN
from V to f . The on time is equal to t = (V /I )
ADJ
ON
OUT ON
• 10pF and t = t – t . The frequency is equal to: Freq.
OFF
s
ON
Equations for setting frequency for 12V to 5V:
= DC/t . The I current is proportional to V , and the
ON
ON
IN
I
= (V – 0.7V)/110k; I = 103μA
IN ON
ON
regulator duty cycle is inversely proportional to V , there-
IN
forethestep-downregulatorwillremainrelativelyconstant
frequency = (I /[2.4V • 10pF]) • DC = 1.79MHz;
ON
frequency as the duty cycle adjustment takes place with
DC = duty cycle, duty cycle is (V /V )
OUT IN
lowering V . The on time is proportional to V
up to a
IN
OUT
t = t + t , t = on-time, t = off-time of the
OFF
S
ON
OFF ON
2.4V clamp. This will hold frequency relatively constant
with different output voltages up to 2.4V. The regulator
switching period is comprised of the on time and off time
as depicted in the following waveform. The on time is
switching period; t = 1/frequency
S
t
must be greater than 400ns, or t – t > 400ns.
S ON
OFF
t
= DC • t
S
ON
equal to t = (V /I ) • 10pF and t = t – t . The
ON
OUT ON
OFF
s
ON
1MHz frequency or 1μs period is chosen for 12V to 5V.
frequency is equal to: Frequency = DC/t ).
ON
4600hvfc
17
LTM4600HV
U
W U U
APPLICATIO S I FOR ATIO
t
must be greater than 400ns, or t – t > 400ns.
S ON
t
= 0.41 • 1μs ≅ 410ns
OFF
ON
t
= DC • t
S
t
= 1μs – 410ns ≅ 590ns
ON
OFF
~450kHz frequency or 2.22μs period is chosen for 5V to
3.3V. Frequency range is about 450kHz to 650kHz from
4.5V to 7V input.
t
and t are above the minimums with adequate guard
OFF
ON
band.
Using the frequency = (I /[2.4V • 10pF]) • DC, solve for
ON
t
t
= 0.66 • 2.22μs ≅ 1.46μs
= 2.22μs – 1.46μs ≅ 760ns
I
ON
= (1MHz • 2.4V • 10pF) • (1/0.41) ≅ 58μA. I current
ON
ON
calculated from 12V input was 103μA, so a resistor from
OFF
f
to ground = (0.7V/15k) = 46μA. 103μA – 46μA =
ADJ
t
and t are above the minimums with adequate guard
OFF
ON
band.
57μA, sets the adequate I current for proper frequency
ON
range for the higher duty cycle conversion of 12V to
5V. Input voltage range is limited to 9V to 16V. Higher
Using the frequency = (I /[2.4V • 10pF]) • DC, solve for
ON
input voltages can be used without the 15k on f . The
ADJ
I
ON
= (450kHz • 2.4V • 10pF) • (1/0.66) ≅ 16μA. I current
ON
inductor ripple current gets too high above 16V, and the
calculated from5V input was39μA, so a resistorfrom f
ADJ
400ns minimum off-time is limited below 9V.
to ground = (0.7V/30.1k) = 23μA. 39μA – 23μA = 16μA,
sets the adequate I current for proper frequency range
ON
Equations for setting frequency for 5V to 3.3V:
for the higher duty cycle conversion of 5V to 3.3V. Input
I
= (V – 0.7V)/110k; I = 39μA
IN ON
ON
voltagerangeislimitedto4.5Vto7V.Higherinputvoltages
can be used without the 30.1k on f . The inductor ripple
frequency = (I /[2.4V • 10pF]) • DC = 1.07MHz;
ADJ
ON
current gets too high above 7V, and the 400ns minimum
DC = duty cycle, duty cycle is (V /V )
OUT IN
off-time is limited below 4.5V.
t = t + t , t = on-time, t = off-time of the
OFF
S
ON
OFF ON
switching period; t = 1/frequency
S
5V to 3.3V at 8A
R1
30.1k
4.5V TO 7V
C5
100pF
C3
10μF
25V
C1
10μF
25V
V
f
ADJ
IN
3.3V AT 8A EFFICIENCY = 94%
EXTV
FCB
V
CC
OUT
+
C2
22μF
C4
330μF
6.3V
V
OSET
R2
22.1k
1%
LTM4600HV
RUN/SOFT-START
RUN/SS
COMP
SV
IN
PGOOD
PGND
OPEN DRAIN
SGND
4600 F22
5V TO 3.3V AT 8A WITH f
LTM4600HV MINIMUM ON-TIME = 100ns
LTM4600HV MINIMUM OFF-TIME = 400ns
= 30.1k
C1, C3: TDK C3216X5R1E106MT
C2: TAIYO YUDEN, JMK316BJ226ML
C4: SANYO POSCAP, 6TPE330MIL
ADJ
4600hvfc
18
LTM4600HV
U
W U U
APPLICATIO S I FOR ATIO
12V to 5V at 8A
VIN to VOUT Stepdown Ratio for
12V to 5V and 5V to 3.3V
R1
15k
5.0
9V TO 16V
3.3V: f
= 30.1k
ADJ
= 15k
4.5 5V: f
ADJ
C5
100pF
C3
10μF
25V
C1
10μF
25V
4.0
V
f
ADJ
IN
5V AT 8A
EFFICIENCY = 94%
3.5
EXTV
FCB
V
CC
OUT
+
C2
22μF
C4
330μF
6.3V
3.0
V
OSET
R2
2.5
LTM4600HV
13.7k
1%
RUN/SOFT-START
RUN/SS
COMP
SV
IN
2.0
PGOOD
PGND
OPEN DRAIN
1.5
SGND
1.0
4600 F23
3.3V AT 8A
5V AT 8A
0.5
0
12V TO 5V AT 8A WITH f
= 15k
C1, C3: TDK C3216X5R1E106MT
C2: TAIYO YUDEN, JMK316BJ226ML
C4: SANYO POSCAP, 6TPE330MIL
ADJ
1
3
5
7
9
11 13 15 17
LTM4600HV MINIMUM ON-TIME = 100ns
LTM4600HV MINIMUM OFF-TIME = 400ns
V
(V)
IN
4600 F24
U
TYPICAL APPLICATIO
V
IN
+
C
(BULK)
C
(CER)
IN
IN
5V TO 24V
GND
150μF
10μF
V
IN
2x
(MULTIPLE PINS)
EXTV
V
V
OUT
CC
OUT
(MULTIPLE PINS)
C3
100pF
SV
IN
C
+
OUT1
C
OUT2
22μF
6.3V
×3
f
ADJ
470μF
V
REFER TO
TABLE 2
V
OSET
OUT
LTM4600HV
COMP
FCB
REFER TO
TABLE 2
RUN/SS
PGOOD
0.6V TO 5V
SGND
REFER TO STEP DOWN
RATIO GRAPH
PGND
(MULTIPLE PINS)
C4
OPT
R1
66.5k
REFER TO
TABLE 1
GND
4600HV F21
Figure 21. Typical Application, 5V to 24V Input, 0.6V to 5V Output, 10A Max
4600hvfc
19
LTM4600HV
U
TYPICAL APPLICATIO
Parallel Operation and Load Sharing
4.5V TO 24V
V
= 0.6V • ([100k/N] + R )/R
SET SET
OUT
WHERE N = 2
C8
10μF
35V
C7
10μF
35V
V
f
ADJ
IN
EXTV
FCB
V
CC
OUT
+
C9
C10
470μF
4V
V
22μF
OSET
x3
LTM4600HV
R4
15.8k
1%
RUN
SV
IN
COMP
PGOOD
SGND
PGND
2.5V AT 20A
RUN/SOFT-START
C4
220pF
C3
10μF
35V
C1
10μF
V
f
ADJ
IN
35V
2.5V
EXTV
V
CC
OUT
+
C2
22μF
x3
C5
470μF
4V
FCB
V
OSET
LTM4600HV
R1
100k
RUN
SV
IN
COMP
PGOOD
PGND
SGND
C1, C3, C7, C8: TAIYO YUDEN, GDK316BJ106ML
C2, C9: TAIYO YUDEN, JMK316BJ226ML-T501
C5, C10: SANYO POSCAP, 4TPE470MCL
4600hv TA02
Current Sharing Between Two
LTM4600HV Modules
12
10
8
12V
IN
OUT
MAX
2.5V
20A
I
OUT2
I
OUT1
6
4
2
0
0
10
TOTAL LOAD
15
20
5
4600hv TA03
4600hvfc
20
LTM4600HV
U
PACKAGE DESCRIPTIO
Z
b b b
Z
6 . 9 8 6 5
5 . 7 1 4 2
6 . 3 5 0 0
3 . 8 1 0 0
1 . 2 7 0 0
5 . 0 8 0 0
4 . 4 4 4 2
3 . 1 7 4 2
1 . 9 0 4 2
2 . 5 4 0 0
0 . 0 0 0 0
0 . 6 3 4 2
0 . 0 0 0 0
0 . 3 1 7 5
0 . 3 1 7 5
0 . 6 3 5 8
1 . 2 7 0 0
3 . 8 1 0 0
6 . 3 5 0 0
1 . 9 0 5 8
3 . 1 7 5 8
2 . 5 4 0 0
5 . 0 8 0 0
4 . 4 4 5 8
5 . 7 1 5 8
6 . 9 4 2 1
4600hvfc
21
LTM4600HV
U
PACKAGE DESCRIPTIO
Pin Assignment Tables
(Arranged by Pin Number)
PIN NAME
PIN NAME
PIN NAME
PIN NAME
PIN NAME
E1
PIN NAME
PIN NAME
PIN NAME
A1
-
B1
V
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
C1
-
-
-
-
-
-
-
-
-
V
-
V
-
V
-
-
-
-
-
-
-
-
-
D1
V
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
V
-
V
-
V
-
-
-
-
-
-
-
-
-
F1
V
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
G1 PGND
H1
-
-
-
-
-
-
IN
IN
IN
A2
-
B2
C2
D2
E2
F2
G2
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
H2
H3
H4
H5
H6
A3
V
-
B3
C3
D3
E3
F3
G3
IN
A4
B4
C4
D4
E4
F4
G4
A5
V
-
B5
C5
D5
E5
F5
G5
IN
A6
B6
C6
D6
E6
F6
G6
A7
V
-
B7
C7
D7
E7
F7
G7
H7 PGND
H8
H9 PGND
H10
H11 PGND
H12
H13 PGND
H14
H15 PGND
H16
H17 PGND
IN
A8
B8
C8
D8
E8
F8
G8
-
A9
V
-
B9
C9
D9
E9
F9
G9
IN
A10
A11
A12
A13
A14
A15
A16
B10
B11
B12
B13
B14
B15
B16
B17
B18
B19
B20
B21
B22
C10
C11
C12
C13
C14
C15
C16
C17
C18
C19
C20
C21
C22
C23
D10
D11
D12
D13
D14
D15
D16
D17
D18
D19
D20
D21
D22
E10
E11
E12
E13
E14
E15
E16
E17
E18
E19
E20
E21
E22
E23
F10
F11
F12
F13
F14
F15
F16
F17
F18
F19
F20
F21
F22
G10
G11
G12
G13
G14
G15
G16
G17
G18
G19
G20
G21
G22
-
IN
IN
IN
IN
IN
IN
V
-
IN
-
V
-
IN
-
f
ADJ
-
-
A17 SV
IN
A18
-
H18
H19
H20
H21
H22
H23
-
-
-
-
-
-
A19 EXTV
CC
A20
A21
A22
A23
-
V
-
OSET
-
B23 COMP
D23 SGND
F23 RUN/SS G23 FCB
PIN NAME
PIN NAME
PIN NAME
PIN NAME
PIN NAME
PIN NAME PIN NAME
PIN NAME
J1 PGND
K1
K2
K3
K4
K5
K6
-
-
-
-
-
-
L1
-
M1
M2 PGND
M3
M4 PGND
M5
M6 PGND
M7
M8 PGND
M9
-
N1
-
P1
-
R1
-
T1
-
J2
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
L2 PGND
N2 PGND
P2
V
-
R2
V
-
T2
V
-
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
J3
L3
L4 PGND
L5
L6 PGND
L7
L8 PGND
L9
L10 PGND
L11
L12 PGND
L13
L14 PGND
L15
L16 PGND
L17
L18 PGND
L19
L20 PGND
L21
L22 PGND
L23
-
-
N3
N4 PGND
N5
N6 PGND
N7
N8 PGND
N9
N10 PGND
N11
N12 PGND
N13
N14 PGND
N15
N16 PGND
N17
N18 PGND
N19
N20 PGND
N21
N22 PGND
N23
-
P3
R3
T3
J4
P4
V
-
R4
V
-
T4
V
-
J5
-
-
-
P5
R5
T5
J6
P6
V
-
R6
V
-
T6
V
-
J7
K7 PGND
K8
-
-
-
P7
R7
T7
J8
P8
V
-
R8
V
-
T8
V
-
J9
K9 PGND
K10
-
-
-
P9
R9
T9
J10
J11
J12
J13
J14
J15
J16
J17
J18
J19
J20
J21
J22
M10 PGND
M11 -
P10
P11
P12
P13
P14
P15
P16
P17
P18
P19
P20
P21
P22
P23
V
-
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
V
-
T10
T11
T12
T13
T14
T15
T16
T17
T18
T19
T20
T21
T22
T23
V
-
K11 PGND
-
-
K12
K13 PGND
K14
K15 PGND
K16
K17 PGND
-
M12 PGND
M13 -
V
-
V
-
V
-
-
-
-
M14 PGND
M15 -
V
-
V
-
V
-
-
-
-
M16 PGND
M17 -
V
-
V
-
V
-
-
-
K18
K19
K20
K21
K22
-
-
-
-
-
-
M18 PGND
M19 -
V
-
V
-
V
-
-
-
M20 PGND
M21 -
V
-
V
-
V
-
-
-
M22 PGND
M23 -
V
-
V
-
V
-
J23 PGOOD K23
-
-
4600hvfc
22
LTM4600HV
U
PACKAGE DESCRIPTIO
Pin Assignment Tables
(Arranged by Pin Number)
PIN NAME
PIN NAME
PIN NAME
PIN NAME
G1
PGND
P2
V
A3
V
V
V
V
V
V
A15
A17
A19
A21
B23
D23
F23
G23
J23
f
ADJ
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
IN
IN
IN
IN
IN
IN
P4
V
V
V
V
V
V
V
V
V
V
A5
H7
H9
H11
H13
H15
H17
PGND
PGND
PGND
PGND
PGND
PGND
SV
IN
P6
P8
A7
A9
A11
A13
EXTV
V
CC
P10
P12
P14
P16
P18
P20
P22
OSET
COMP
B1
V
IN
SGND
RUN/SS
FCB
J1
PGND
C10
C12
C14
V
IN
V
IN
V
IN
K7
K9
K11
K13
K15
K17
PGND
PGND
PGND
PGND
PGND
PGND
D1
V
R2
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
IN
PGOOD
R4
E10
E12
E14
V
IN
V
IN
V
IN
R6
R8
R10
R12
R14
R16
R18
R20
R22
L2
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
F1
V
IN
L4
L6
L8
L10
L12
L14
L16
L18
L20
L22
T2
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
T4
T6
T8
T10
T12
T14
T16
T18
T20
T22
M2
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
M4
M6
M8
M10
M12
M14
M16
M18
M20
M22
N2
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
N4
N6
N8
N10
N12
N14
N16
N18
N20
N22
4600hvfc
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
23
LTM4600HV
U
TYPICAL APPLICATIO
1.8V, 10A Regulator
4.5V TO 22V
C5
100pF
C2
10μF
35V
C1
10μF
35V
V
f
ADJ
IN
1.8V AT 10A
EXTV
FCB
V
CC
OUT
+
C3
22μF
x3
C4
470μF
4V
V
OSET
R1
100k
LTM4600HV
RUN
SV
IN
COMP
PGOOD
PGND
PGOOD
R2
49.9k
1%
SGND
C1, C2: TAIYO YUDEN, GDK316BJ106ML
C3: TAIYO YUDEN, JMK316BJ226ML-T501
C4: SANYO POSCAP, 4TPE470MCL
4600hv TA04
RELATED PARTS
PART NUMBER
LTC2900
DESCRIPTION
COMMENTS
Quad Supply Monitor with Adjustable Reset Timer
Power Supply Tracking Controller
Synchronous Isolated Flyback Controllers
10A DC/DC μModule
Monitors Four Supplies; Adjustable Reset Timer
Tracks Both Up and Down; Power Supply Sequencing
No Optocoupler Required; 3.3V, 12A Output; Simple Design
Basic 10A DC/DC μModule
LTC2923
LT3825/LT3837
LTM4600
LTM4601
12A DC/DC μModule with PLL, Output Tracking/
Margining and Remote Sensing
Synchronizable, PolyPhase Operation to 48A, LTM4601-1 Version has no
Remote Sensing
LTM4602
LTM4603
6A DC/DC μModule
Pin Compatible with the LTM4600
6A DC/DC μModule with PLL and Outpupt Tracking/ Synchronizable, PolyPhase Operation to 48A, LTM4601-1 Version has no
Margining and Remote Sensing
Remote Sensing, Pin Compatible with the LTM4601
®
This product contains technology licensed from Silicon Semiconductor Corporation.
4600hvfc
LT 0707 REV C • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
24
●
●
© LINEAR TECHNOLOGY CORPORATION 2005
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
相关型号:
LTM4600IV#PBF
LTM4600 - 10A High Efficiency DC/DC µModule (Power Module); Package: LGA; Pins: 104; Temperature Range: -40°C to 85°C
Linear
LTM4600IV#TRPBF
IC IC,SMPS CONTROLLER,CURRENT-MODE,LGA,104PIN,PLASTIC, Switching Regulator or Controller
Linear
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