LTM4600HVMPV#PBF_技术文档

LTM4600HV

10A, 28V High Efﬁciency

IN

DC/DC µModule

FeaTures

DescripTion

n

Complete Switch Mode Power Supply

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.

n

Wide Input Voltage Range: 4.5V to 28V

n

10A DC, 12A Peak Output Current

n

Parallel Two µModule™ DC/DC Converters for 20A

Output Current

0.6V to 5V Output Voltage

n

1.5% Output Voltage Regulation

n

Ultrafast Transient Response

n

Current Mode Control

n

–55°C to 125°C Operating Temperature Range

(LTM4600HVMPV)

The low profile package (2.82mm) 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.

n

RoHS Compliant Package with Gold Pad Finish (e4)

n

Up to 92% Efficiency

Programmable Soft-Start

Output Overvoltage Protection

Optional Short-Circuit Shutdown Timer

n

Small Footprint, Low Profile (15mm × 15mm ×

2.82mm) LGA Package

applicaTions

The LTM4600HV is packaged in a compact (15mm ×

15mm) and low profile (2.82mm) over-molded Land Grid

Array (LGA) package suitable for automated assembly by

standard surface mount equipment. The LTM4600HV is

RoHS compliant.

n

Telecom and Networking Equipment

n

Military and Avionics Systems

n

Industrial Equipment

n

Point of Load Regulation

n

L, LT, LTC, LTM, µModule and OPTI-LOOP are registered trademarks of Linear Technology

Corporation. All other trademarks are the property of their respective owners.

Servers

Efficiency vs Load Current with 24V_IN(FCB = 0)

Typical applicaTion

100

10A µModule Power Supply with 4.5V to 28V Input

90

V

80

70

60

50

OUT

V

IN

2.5V*

10A

V

OUT

IN

4.5V TO 28V

ABSMAX

C

OUT

IN

LTM4600HV

V

OSET

PGND SGND

31.6k

1.8V

2.5V

3.3V

OUT

40

30

4600hv TA01a

5V

OUT

*REVIEW DE-RATING CURVE AT

THE HIGHER INPUT VOLTAGE

2

4

8

0

10

6

LOAD CURRENT (A)

4600HV TA01b

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LTM4600HV

absoluTe MaxiMuM raTings

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

IN

IN ADJ

COMP

SGND

RUN/SS

FCB

V

, COMP ............................................ –0.3V to 2.7V

OSET

V

IN

Operating Temperature Range (Note 2)

E and I Grades .....................................–40°C to 85°C

MP Grade........................................... –55°C to 125°C

Junction Temperature ........................................... 125°C

Storage Temperature Range .................. –55°C to 125°C

Peak Solder Reflow Body Temperature ................. 245°C

PGOOD

PGND

V

OUT

LGA PACKAGE

104-LEAD (15mm × 15mm × 2.82mm)

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

PART MARKING

PACKAGE

TYPE

MSL

RATING

TEMPERATURE RANGE

(SEE NOTE 2)

PART NUMBER

PAD OR BALL FINISH

DEVICE

FINISH CODE

LTM4600HVEV#PBF

LTM4600HVIV#PBF

LTM4600HVMPV#PBF

LTM4600HVEV

LTM4600HVIV

LTM4600HVMPV

–40°C to 85°C

–55°C to 125°C

Au (RoHS)

e4

LGA

3

•ꢀ Consult Marketing for parts specified with wider operating temperature

ranges. *Pad or ball finish code is per IPC/JEDEC J-STD-609.

•ꢀ Recommended LGA and BGA PCB Assembly and Manufacturing

Procedures: www.linear.com/umodule/pcbassembly

•ꢀ LGA and BGA Package and Tray Drawings: www.linear.com/packaging

•ꢀ Terminal Finish Part Marking: www.linear.com/leadfree

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LTM4600HV

elecTrical characTerisTics

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T_A= 25°C, V_IN= 12V. External C_IN= 120µF, C_OUT= 200µF/Ceramic per typical

application (front page) configuration.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

l

V

Input DC Voltage

Abs Max 28V for Tolerance on 24V Inputs

4.5

28

V

IN(DC)

Output Voltage

FCB = 0V

OUT(DC)

V

IN

= 5V or 12V, V

= 1.5V, I = 0A

OUT

1.478

1.470

1.50

1.522

1.530

V

OUT

Input Specifications

V

Under Voltage Lockout Threshold

Input Inrush Current at Startup

I

= 0A

3.4

4

V

IN(UVLO)

OUT

I

= 0A, V

= 1.5V, FCB = 0

INRUSH(VIN)

OUT

V

= 5V

= 12V

= 24V

0.6

0.7

0.8

A

IN

V

I

Input Supply Bias Current

I

= 0A, EXTV Open

Q(VIN)

OUT CC

V

= 12V, V

= 24V, V

= 1.5V, FCB = 5V

1.2

42

mA

µA

IN

OUT

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

I

Input Supply Current

V

IN

V

IN

V

IN

V

IN

= 12V, V

= 1.5V, I

= 3.3V, I

= 10A

1.52

3.13

3.64

1.6

A

S(VIN)

OUT

= 5V, V

= 1.5V, I

= 10A

OUT

= 24V to 3.3V at 10A, EXTV = 5V

CC

Output Specifications

I

Output Continuous Current Range

V

= 12V, V

= 24V, V

= 1.5V

= 2.5V (Note 3)

0

10

A

OUTDC

IN

OUT

(See Output Current Derating Curves for

Different V , V

and T )

A

IN OUT

l

ΔV

Line Regulation Accuracy

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

= 5V

1

1.5

%

IN

V

OUT

= 12V (Notes 4, 5)

= 1.5V, FCB = 0V, I

V

Output Ripple Voltage

Output Ripple Voltage Frequency

Turn-On Time

V

IN

= 12V, V

= 0A

10

15

mV

P-P

OUT(AC)

OUT

fs

FCB = 0V, I

= 5A, V = 12V, V = 1.5V

OUT

850

kHz

OUT

IN

t

V

OUT

= 1.5V, I

IN

= 1A

OUT

START

V

= 12V

= 5V

0.5

0.7

ms

ΔV

Voltage Drop for Dynamic Load Step

V

C

= 1.5V, Load Step: 0A/µs to 5A/µs

36

mV

OUTLS

OUT

ꢀ=ꢀ3ꢀ•ꢀ22µF 6.3V, 470µF 4V POSCAP,

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

Output Current Limit

Output Voltage in Foldback

OUTPK

V

= 24V, V

= 12V, V

= 2.5V

= 1.5V

17

A

IN

OUT

= 5V, V

= 1.5V

Control Stage

l

V

OSET

Voltage at V

I

= 0A, V = 1.5V

OUT

0.591

0.594

0.6

0.609

0.606

V

OSET

OUT

V

RUN ON/OFF Threshold

0.8

1.5

2

V

RUN/SS

4600hvfe

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LTM4600HV

elecTrical characTerisTics

The l denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T_A= 25°C, V_IN= 12V. External C_IN= 120µF, C_OUT= 200µF/Ceramic per typical

application (front page) configuration.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

I

Soft-Start Charging Current

V

= 0V

= 4V

–0.5

–1.2

–3

µA

RUN(C)/SS

RUN(D)/SS

RUN/SS

I

Soft-Start Discharging Current

V

0.8

1.8

100

16

3

µA

mV

mA

kΩ

V

– SV

EXTV = 0V, FCB = 0V

CC

IN

I

Current into EXTV Pin

EXTV = 5V, FCB = 0V, V = 1.5V, I = 0A

EXTVCC

CC

OUT

R

Resistor Between V

and V Pins

OSET

100

0.6

–1

FBHI

FCB

OUT

V

Forced Continuous Threshold

0.57

0.63

–2

I

Forced Continuous Pin Current

V

FCB

= 0.6V

µA

FCB

PGOOD Output

ΔV

PGOOD Upper Threshold

PGOOD Lower Threshold

PGOOD Hysteresis

V

Rising

7.5

10

–10

2

12.5

%

V

OSETH

OSET

Falling

–7.5

–12.5

OSETL

OSET

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 LTM4600HVI

is guaranteed over the –40°C to 85°C temperature range. The

LTM46000HVMP is guaranteed and tested over the –55°C to 125°C

temperature range.

Note 3: For output current derating at high temperature, please refer to

Thermal Considerations and Output Current Derating discussion.

Note 4: Test assumes current derating versus temperature.

Note 5: Guaranteed by correlation.

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LTM4600HV

Typical perForMance characTerisTics

(See Figure 21 for all curves)

Efficiency vs Load Current

with 24V_IN(FCB = 0)

Efficiency vs Load Current

with 5V_IN(FCB = 0)

Efficiency vs Load Current

with 12V_IN(FCB = 0)

100

90

80

70

60

50

40

30

100

90

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

1.8V

2.5V

3.3V

5V

0.6V

1.2V

1.5V

2.5V

OUT

8

10

2

4

8

0

2

4

6

0

10

2

4

8

6

0

10

6

LOAD CURRENT (A)

4600hv G01

4600hv G02

4600hv G03

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

= 3 • 22µF 6.3V CERAMICS

25µs/DIV

V

= 12V

OUT

IN

1.5V AT 5A/µs LOAD STEP

= 1.5V

C

OUT

= 3 • 22µF 6.3V CERAMICS

OUT

0.1

10

1

470µF 4V SANYO POSCAP

C3 = 100pF

470µF 4V SANYO POSCAP

C3 = 100pF

LOAD CURRENT (A)

4600hv G04

1.8V Transient Response

2.5V Transient Response

3.3V Transient Response

4600HV G07

4600HV G09

4600HV G08

25µs/DIV

1.8V AT 5A/µs LOAD STEP

3.3V AT 5A/µs LOAD STEP

2.5V AT 5A/µs LOAD STEP

C

= 3 • 22µF 6.3V CERAMICS

C

= 3 • 22µF 6.3V CERAMICS

C

= 3 • 22µF 6.3V CERAMICS

OUT

470µF 4V SANYO POSCAP

C3 = 100pF

470µF 4V SANYO POSCAP

C3 = 100pF

470µF 4V SANYO POSCAP

C3 = 100pF

4600hvfe

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LTM4600HV

Typical perForMance characTerisTics _{(See Figure 21 for all curves)}

Start-Up, I_OUT= 10A

(Resistive Load)

Start-Up, I_OUT= 0A

V

OUT

(0.5V/DIV)

OUT

(0.5V/DIV)

I

IN

(0.5A/DIV)

4600HV G10

4600HV G11

200µs/DIV

V

C

= 12V

V

C

= 12V

IN

= 1.5V

OUT

= 200µF

NO EXTERNAL SOFT-START CAPACITOR

Short-Circuit Protection,

I_OUT= 0A

Short-Circuit Protection,

I_OUT= 10A

V_INto V_OUTStep-Down 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

OUT

V

OUT

(0.5V/DIV)

I

3.3V

IN

(0.2A/DIV)

(0.5A/DIV)

2.5V

1.8V

4600HV G12

4600HV G13

200µs/DIV

20µs/DIV

1.5V

1.2V

V

C

= 12V

OUT

V

C

= 12V

OUT

IN

= 1.5V

= 2× 200µF/X5R

NO EXTERNAL SOFT-START CAPACITOR

= 2× 200µF/X5R

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

12V Input Load Regulation vs

Temperature

V_OSETvs Temperature

Start-Up Waveform, T_A= –55°C

0.00

–0.05

–0.10

–0.15

–0.20

–0.25

–0.30

–0.35

–0.40

–0.45

0.610

0.605

0.600

0.595

25°C

100°C

4600HV G16

–45°C

V

I

= 12V

400μs/DIV

IN

OUT

= 1.5V

= 10A

0.590

0

5

10

–55 –25

5

35

65

95

125

LOAD CURRENT

TEMPERATURE (°C)

4600HV G17

4600HV G15

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LTM4600HV

pin FuncTions

(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 switch-

ing frequency. The LTM4600HV switching frequency is

typically 850kHz. An external resistor to ground can be

selected to reduce the one-shot timer current, thus lower

the switching frequency to accommodate a higher duty

cyclestepdownrequirement.Seetheapplicationssection.

pin and the V pin. This resistor must supply a minimum

5µA pull up current. The RUN/SS pin has an internal 6V

Zener to ground.

IN

SV (Pin A17): Supply Pin for Internal PWM Controller.

IN

Leavethispinopenoraddadditionaldecouplingcapacitance.

EXTV (Pin A19): External 5V supply pin for controller. If

CC

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.

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

V

(PinA21):TheNegativeInputofTheErrorAmplifier.

OSET

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.

Internally, this pin is connected to V

with a 100k preci-

OUT

sionresistor.Differentoutputvoltagescanbeprogrammed

withadditionalresistorsbetweentheV andSGNDpins.

OSET

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).

PGND (Bank 2): Power ground pins for both input and

output returns.

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

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LTM4600HV

siMpliFieD block DiagraM

SV

IN

RUN/SS

LTM4600HV

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

Decoupling requireMenTs ^T_A^{= 25°C, V}_IN= 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

Applications Information Section

IN

OUT

4600hvfe

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LTM4600HV

operaTion

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

output voltage programmable via one external resistor

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 soft-start capacitor. When this voltage reaches 1.5V,

the controller turns on and begins switching.

from 0.6V to 5.0V . The input voltage range is 4.5V to

DC

28V. A simplified block diagram is shown in Figure 1 and

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

the 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

voltage. Also EXTV must be sequenced after V .

CC IN

IN

Recommended for 24V operation to lower temperature

in the µModule.

4600hvfe

9

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LTM4600HV

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The typical LTM4600HV application circuit is shown in

Figure 21. External component selection is primarily de-

terminedbythemaximumloadcurrentandoutputvoltage.

down when Q

is on and Q is off. If the output

UP

DOWN

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

(R_SETR_UP)• V_O•(1+M%)

(R_SETR_UP)+100kΩ

The PWM controller of the LTM4600HV has an internal

0.6V 1% reference voltage. As shown in the block dia-

gram, a 100k/0.5% internal feedback resistor connects

= 0.6V

R_SET• V_O•(1–M%)

V

and V

pins. Adding a resistor R from V

OUT

OSET SET OSET

= 0.6V

R_SET+(100kΩ R_DOWN

)

pin to SGND pin programs the output voltage:

100k+R_SET

V_O= 0.6V •

Input Capacitors

R_SET

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

resistor

SET

for typical output voltages:

ule. In Figure 21, the bulk input capacitor C is selected

Table 1.

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

V_O

D =

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

V

IN

Without considering the inductor current ripple, the RMS

current of the input capacitor can be estimated as:

I_O(MAX)

I_CIN(RMS)

=

• D•(1−D)

resistor R , several external components are added.

SET

η%

Turn off both transistor Q and Q

margining. When Q is on and Q

voltage is margined up. The output voltage is margined

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

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

should be placed directly adjacent the module input pins

Q

UP

2N7002

4600hv F02

Figure 2. LTM4600HV Margining Implementation

4600hvfe

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in the PCB layout to minimize the trace inductance and

high frequency AC noise.

V to V

Step-Down Ratios

IN

OUT

There are restrictions in the maximum V to V

step

IN

OUT

down ratio that can be achieved for a given input voltage.

These constraints are shown in V to V Step-Down

Ratio in the Typical Performance Characteristics section.

Note that additional thermal derating may apply. See the

Thermal Considerations and Output Current Derating sec-

tions of this data sheet.

Output Capacitors

IN

OUT

TheLTM4600HVisdesignedforlowoutputvoltageripple.

ThebulkoutputcapacitorsC ischosenwithlowenough

OUT

effectiveseriesresistance(ESR)tomeettheoutputvoltage

ripple and transient requirements. C

can be low ESR

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.

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

(I ≤ 75µA). Releasing the pin allows an internal 1.2µA

Q

current source to charge up the timing capacitor C .

SS

Inside LTM4600HV, there is an internal 1000pF capacitor

fromRUN/SSpintoground. IfRUN/SSpinhasanexternal

capacitor C

about:

to ground, the delay before starting is

SS_EXT

Fault Conditions: Current Limit and Over current

Foldback

1.5V

1.2µA

t_DELAY

=

•(C_{SS_EXT}+1000pF)

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.

When the voltage on RUN/SS pin reaches 1.5V, the

LTM4600HVinternalswitchesareoperatingwithaclamp-

ing of the maximum output inductor current limited by

the RUN/SS pin total soft-start capacitance. As the RUN/

SS pin voltage rises to 3V, the soft-start clamping of the

inductor current is released.

To furtherlimitcurrentintheeventofanoverloadcondition,

the LTM4600HV provides foldback current limiting. If the

output voltage falls by more than 50%, then the maximum

output current is progressively lowered to about one sixth

of its full current limit value.

4600hvfe

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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)

SANYO POSCAP

6TPE330MIL (330µF, 6.3V)

2R5TPE470M9 (470µF, 2.5V)

4TPE470MCL (470µF, 4V)

6TPD470M (470µF, 6.3V)

TAIYO YUDEN

V

C

C3

V

IN

(V)

5

12

5

12

5

12

5

12

24

7

12

24

15

20

DROOP

(mV)

PEAK TO PEAK

RECOVERY TIME

(µs)

LOAD STEP

(A/µs)

OUT

IN

OUT1

OUT2

COMP

(V)

1.2

1.5

1.8

2.5

2.8

3.3

5

(CERAMIC)

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

330µF 6.3V

NONE

(mV)

68

70

80

98

68

70

80

98

75

79

84

118

75

79

89

108

81

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

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

NONE 100pF

35

40

49

35

40

49

36

37

44

61

36

37

44

54

40

44

46

62

40

44

62

48

56

57

60

48

51

56

70

56

50

64

66

82

100

52

64

76

74

188

159

25

20

25

20

25

20

25

20

30

20

30

20

30

25

30

25

30

35

25

30

35

30

25

30

25

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

330µF 6.3V

470µF 4V

NONE

470µF 4V

330µF 6.3V

NONE

470µF 6.3V

NONE

5

*X7R is recommended for extended temperature range.

4600hvfe

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After the controller has been started and given adequate

time to charge up the output capacitor, C is used as a

V

SS

RUN/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

4V

3.5V

3V

beginsdischargingC . Ifthefaultconditionpersistsuntil

SS

1.5V

SHORT-CIRCUIT

LATCH ARMED

the RUN/SS pin drops to 3.5V, then the controller turns

off both power MOSFETs, shutting down the converter

permanently. The RUN/SS pin must be actively pulled

down to ground in order to restart operation.

t

SOFT-START

CLAMPING

OF I RELEASED

SHORT-CIRCUIT

LATCHOFF

OUTPUT

OVERLOAD

HAPPENS

L

The over-current protection timer requires the soft-start

V

O

timing capacitor C be made large enough to guarantee

SS

75%V

O

that the output is in regulation by the time C has reached

SS

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:

t

SWITCHING

STARTS

4600hv F03

Figure 3. RUN/SS Pin Voltage During Startup and

Short-Circuit Protection

C_OUT• V_OUT

C_{SS_EXT}+1000pF >

10kV

Generally 0.1µF is more than sufficient.

V

IN

V

IN

RECOMMENDED VALUES FOR RUN/SS

Since the load current is already limited by the current

mode control and current foldback circuitry during a

short-circuit,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

current greater than 5µA but less than 80µA to the RUN/

SS pin. The additional current prevents the discharge of

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

Figure 4. Defeat Short-Circuit Latchoff with a Pull-Up

Resistor to V_IN

C

during a fault and also shortens the soft-start period.

SS

Using a resistor from RUN/SS pin to V is a simple solu-

IN

tiontodefeatlatchoff. Anypull-upnetworkmustbeableto

maintain RUN/SS above 4V maximum latchoff threshold

andovercomethe4µAmaximumdischargecurrent.Witha

pull-upresistor,thedelaybeforestartingisapproximately:

t_DELAY= –R_RUN/SS• C

+1000pF

(

)

SS_EXT

⎛

⎞

1.5V

V + 1.2µA •R

•ln⎜1−

⎟

⎜

(

)

⎝

⎠

IN

RUN/SS

Figure 3 shows a conceptual drawing of V

startup and short-circuit.

during

RUN

4600hvfe

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Enable

EXTV Connection

CC

The RUN/SS pin can be driven from logic as shown in

Figure 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

= 18mAꢀ•ꢀ(V – 5V)

IN

LDO_LOSS

LTM4600HV

ON

The LTM4600HV also provides an external gate driver

PGND SGND

voltage pin EXTV . If there is a 5V rail in the system, it

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

IN

required that the EXTV voltage can not be higher than

CC

V pin voltage.

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

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

TB1

IN

R

TB2

R

LTM4600HV

V

TA1

V

FB2

1.5V

OSET

OUT

GND

R

TA2

66.5k

4600hv F06

Figure 6. Output Voltage Tracking with the LTC2923 Controller

4600hvfe

14

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LTM4600HV

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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

parameters are correlated to the measure values, and

JA

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 heat sinking, 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. TheOPTI-LOOP™currentmodecontrolensures

good current sharing among modules to balance the ther-

mal stress. The new feedback equation for two or more

LTM4600HVs in parallel is:

at the junction of the device.

Safety Considerations

TheLTM4600HVmodulesdonotprovideisolationfromV

IN

to V . There is no internal fuse. If required, a slow blow

OUT

fusewitharatingtwicethemaximuminputcurrentshould

be provided to protect each unit from catastrophic failure.

100k

+R_SET

N

Layout Checklist/Example

V_OUT= 0.6V •

R_SET

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.

where N is the number of LTM4600HVs in parallel.

V

OUT

V

OUT

IN

(20A

)

MAX

LTM4600HV

•ꢀ Use large PCB copper areas for high current path, in-

PGND COMP

V

SGND

OSET

cluding V , PGND and V . It helps to minimize the

IN

OUT

R

SET

PCB conduction loss and thermal stress

•ꢀ Place high frequency ceramic input and output capaci-

COMP

V

SGND

OSET

tors next to the V , PGND and V

pins to minimize

IN

OUT

V

LTM4600HV

V

OUT

IN

high frequency noise

PGND

•ꢀ Place a dedicated power ground layer underneath

4600hv F07

the unit

Figure 7. Parallel Two µModules with Load Sharing

•ꢀ To minimizetheviaconductionlossandreducemodule

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 heat sink-

JA

ing methods. Thermal models are derived from several

temperature measurements at the bench, and thermal

modelinganalysis.ApplicationNote103providesadetailed

Figure20givesagoodexampleoftherecommendedlayout.

4600hvfe

15

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4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

10

9

V

= 1.5V

V

= 5V

V

= 5V

OUT

IN

OUT

IN

OUT

= 1.5V

9

18V LOSS

8

12V LOSS

7

6

5V LOSS

5

0 LFM

200 LFM

400 LFM

5

0 LFM

200 LFM

400 LFM

4

0

2

4

6

8

10

50

60

70

80

90

50

60

70

80

90

100

OUTPUT CURRENT (A)

AMBIENT TEMPERATURE (°C)

4600hv F08

4600hv F09

4600hv F10

Figure 8. 1.5V Power Loss Curves

vs Load Current

Figure 9. No Heat Sink

Figure 10. BGA Heat Sink

10

9

10

9

8

7

6

5

4

3

2

1

0

10

9

V

= 12V

OUT

V

= 18V

OUT

V

= 12V

IN

V

IN

OUT

= 1.5V

8

7

6

5

0 LFM

200 LFM

400 LFM

0 LFM

200 LFM

400 LFM

5

0 LFM

200 LFM

400 LFM

4

3

4

50

60

70

80

90

100

40

50

60

70

80

90

50 55 60 65 70 75 80 85 90

AMBIENT TEMPERATURE (°C)

4600hv F11

AMBIENT TEMPERATURE (°C)

4600hv F12

4600hv F13

Figure 13. No Heat Sink

Figure 11. No Heat Sink

Figure 12. BGA Heat Sink

10

8

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0

10

9

8

7

6

5

4

3

2

1

0

V

= 18V

V

= 12V

OUT

IN

OUT

IN

= 1.5V

= 3.3V

24V LOSS

6

4

12V LOSS

2

0 LFM

200 LFM

400 LFM

0 LFM

200 LFM

400 LFM

0

50

60

70

80

90

100

0

2

4

6

8

10

40

50

60

70

80

90

AMBIENT TEMPERATURE (°C)

OUTPUT CURRENT (A)

AMBIENT TEMPERATURE (°C)

4600hv F14

4600hv F15

4600hv F16

Figure 14. BGA Heat Sink

Figure 16. No Heat Sink

Figure 15. 3.3V Power Loss

Curves vs Load Current

4600hvfe

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10

9

V

= 12V

V

= 24V

0 LFM

200 LFM

400 LFM

IN

OUT

IN

OUT

= 3.3V

= 3.3V TEMPERATURE

DE-RATING

9

8

6

7

4

6

2

5

0 LFM

200 LFM

400 LFM

0 LFM

200 LFM

400 LFM

5

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)

4600hv F17

4600hv F18.eps

4600hv F19.eps

Figure 17. BGA Heat Sink

Figure 18. No Heat Sink

Figure 19. BGA Heat Sink

Table 3. 1.5V Output

DERATING CURVE

Figures 9, 11, 13

Figures 10, 12, 14

V

(V)

POWER LOSS CURVE

Figure 8

AIR FLOW (LFM)

HEAT SINK

None

θ

JA

(°C/W)

IN

5, 12, 18

0

15.2

14

Figure 8

200

400

0

None

Figure 8

None

12

Figure 8

BGA Heat Sink

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)

HEAT SINK

None

θ

(°C/W)

JA

IN

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 Heat Sink

Figures 17, 19

Figure 15

200

400

Figures 17, 19

Figure 15

4600hvfe

17

For more information www.linear.com/LTM4600HV

LTM4600HV

applicaTions inForMaTion

V

t

IN

ON

(DC) DUTY CYCLE =

t

s

t

V

OUT

ON

DC =

=

t

s

V

IN

DC

FREQ =

t

ON

t

ON

C

IN

OFF

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

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

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

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 /[2.4Vꢀ •ꢀ 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

OUT

IN

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

ON

= DCꢀ•ꢀt

S

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

4600hvfe

18

For more information www.linear.com/LTM4600HV

LTM4600HV

applicaTions inForMaTion

t

must be greater than 400ns, or t – t > 400ns.

t ꢀ=ꢀ0.41ꢀ•ꢀ1µs @ 410ns

ON

OFF

S

ON

t

ON

= DCꢀ•ꢀt

S

t

= 1µs – 410ns @ 590ns

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 /[2.4Vꢀ•ꢀ10pF])ꢀ•ꢀDC, solve for

ON

t ꢀ=ꢀ0.66ꢀ•ꢀ2.22µs @ 1.46µs

ON

I

= (1MHzꢀ•ꢀ2.4Vꢀ•ꢀ10pF)ꢀ•ꢀ(1/0.41)ꢀ@ 58µA. I current

ON

calculated from 12V input was 103µA, so a resistor from

t

= 2.22µs – 1.46µs @ 760ns

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 /[2.4Vꢀ•ꢀ10pF])ꢀ•ꢀDC, solve for

ON

input voltages can be used without the 15k on f . The

ADJ

I

ON

= (450kHzꢀ•ꢀ2.4Vꢀ•ꢀ10pF)ꢀ•ꢀ(1/0.66)ꢀ@ 16µA. I current

ON

inductor ripple current gets too high above 16V, and the

calculated from 5V input was 39µA, so a resistor from 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 /[2.4Vꢀ •ꢀ 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

4600hvfe

19

For more information www.linear.com/LTM4600HV

LTM4600HV

applicaTions inForMaTion

12V to 5V at 8A

V_INto V_OUTStep-Down Ratio for

12V to 5V and 5V to 3.3V

R1

15k

5.0

9V TO 16V

3.3V: f

= 30.1k

ADJ

4.5 5V: f

= 15k

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

+

3.0

C2

22μF

C4

330μF

6.3V

V

OSET

2.5

R2

13.7k

1%

LTM4600HV

2.0

RUN/SOFT-START

RUN/SS

COMP

SV

IN

1.5

PGOOD

PGND

OPEN DRAIN

1.0

SGND

3.3V AT 8A

5V AT 8A

0.5

4600 F23

0

1

3

5

7

9

11 13 15 17

12V TO 5V AT 8A WITH f

LTM4600HV MINIMUM ON-TIME = 100ns

LTM4600HV MINIMUM OFF-TIME = 400ns

= 15k

C1, C3: TDK C3216X5R1E106MT

C2: TAIYO YUDEN, JMK316BJ226ML

C4: SANYO POSCAP, 6TPE330MIL

ADJ

V

(V)

IN

4600 F24

Typical applicaTions

V

IN

+

C

(BULK)

C

(CER)

IN

5V TO 24V

GND

150μF

10μF

V

IN

2x

(MULTIPLE PINS)

EXTV

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

4600hvfe

20

For more information www.linear.com/LTM4600HV

LTM4600HV

Typical applicaTions

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

V

OSET

22μF

470μF

x3

4V

LTM4600HV

R4

15.8k

1%

RUN

SV

IN

COMP

PGOOD

PGND

SGND

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

10

TOTAL LOAD

15

20

5

4600hv TA03

4600hvfe

21

For more information www.linear.com/LTM4600HV

LTM4600HV

package DescripTion

Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.

Z

b b b

Z

6 . 9 8 6 5

4 . 4 4 4 2

6 . 3 5 0 0

3 . 8 1 0 0

1 . 2 7 0 0

5 . 7 1 4 2

3 . 1 7 4 2

5 . 0 8 0 0

2 . 5 4 0 0

0 . 0 0 0 0

1 . 9 0 4 2

0 . 0 0 0 0

1 . 9 0 5 8

0 . 6 3 4 2

0 . 6 3 5 8

0 . 3 1 7 5

1 . 2 7 0 0

3 . 8 1 0 0

6 . 3 5 0 0

2 . 5 4 0 0

5 . 0 8 0 0

3 . 1 7 5 8

4 . 4 4 5 8

5 . 7 1 5 8

6 . 9 4 2 1

4600hvfe

22

For more information www.linear.com/LTM4600HV

LTM4600HV

package DescripTion

Pin Assignment Tables

(Arranged by Pin Number)

PIN NAME

C1

PIN NAME

E1

PIN NAME

A1

-

B1

V

-

V

-

V

-

V

-

D1

V

-

V

-

V

-

V

-

F1

V

-

G1 PGND

H1

H2

H3

H4

H5

H6

-

IN

A2

-

B2

C2

D2

E2

F2

G2

-

A3

V

-

B3

C3

D3

E3

F3

G3

IN

A4

B4

C4

D4

E4

F4

G4

A5

V

-

B5

C5

D5

E5

F5

G5

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

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

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

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

-

4600hvfe

23

For more information www.linear.com/LTM4600HV

LTM4600HV

package DescripTion

Pin Assignment Tables

(Arranged by Pin Number)

PIN NAME

G1

PGND

P2

V

A3

V

A15

A17

A19

A21

B23

D23

F23

G23

J23

f

ADJ

OUT

IN

P4

V

A5

H7

H9

H11

H13

H15

H17

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

K7

K9

K11

K13

K15

K17

PGND

D1

V

R2

V

IN

PGOOD

OUT

R4

E10

E12

E14

V

IN

R6

R8

R10

R12

R14

R16

R18

R20

R22

L2

PGND

F1

V

IN

L4

L6

L8

L10

L12

L14

L16

L18

L20

L22

T2

V

OUT

T4

T6

T8

T10

T12

T14

T16

T18

T20

T22

M2

PGND

M4

M6

M8

M10

M12

M14

M16

M18

M20

M22

N2

PGND

N4

N6

N8

N10

N12

N14

N16

N18

N20

N22

4600hvfe

24

For more information www.linear.com/LTM4600HV

LTM4600HV

revision hisTory ^{(Revision history begins at Rev E)}

REV

DATE

DESCRIPTION

PAGE NUMBER

E

5/14

Added reflow temperature.

Updated the Order Table.

Updated Notes.

2

4

Updated the Soft-Start and Latchoff section.

11, 13

4600hvfe

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.

25

For more information www.linear.com/LTM4600HV

LTM4600HV

Typical applicaTion

1.8V, 10A Regulator

4.5V TO 22V

C5

100pF

C2

10μF

35V

C1

10μF

V

f

ADJ

IN

35V

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 DESCRIPTION

COMMENTS

LTM4649

16V , 10A Step-Down μModule Regulator

4.5V ≤ V ≤ 16V, 0.6V ≤ V

≤ 3.3V, PLL Input, Remote Sense Amplifier, V

OUT

IN

OUT

tracking, 9mm × 15mm x 4.92mm BGA

LTM4641

38V , 10A Step-Down μModule Regulator

4.5V ≤ V ≤ 38V, 0.6V ≤ V

≤ 6V, Adjustable Protection Trip Thresholds for Many

OUT

IN

with Advanced Input & Load Protection

Faults: (Output Overvoltage, Input Overvoltage, Input Undervoltage, Overtemperature),

15mm × 15mm × 5.01mm BGA

LTM4633

LTM4627

LTM4611

LTM4613

LTM8061

Triple 10A, 16V Step-Down DC/DC μModule 4.7V ≤ V ≤ 16V, 0.8V ≤ V

≤ 1.8V, 0.8V ≤ V

≤ 5.5V, PLL input, V

Soft-Start

IN

OUT1,2

OUT3

OUT

Regulator

and Tracking, PGOOD, Internal Temperature Monitor, 15mm × 15mm × 5.01mm BGA

20V , 15A DC/DC Step-Down μModule

4.5V ≤ V ≤ 20V, 0.6V ≤ V ≤ 5V, PLL Input, V Tracking, Remote Sense Amplifier,

IN

OUT

Regulator

15mm × 15mm × 4.32mm LGA or 15mm × 15mm × 4.92mm BGA

1.5V

, 15A DC/DC Step-Down μModule 1.5V ≤ V ≤ 5.5V, 0.8V ≤ V

≤ 5V, PLL Input, Remote Sense Amplifier, V

Tracking,

OUT

IN(MIN)

IN

OUT

Regulator

15mm × 15mm × 4.32mm LGA

36V , 8A EN55022 Class B DC/DC

5V ≤ V ≤ 36V, 3.3V ≤ V

≤ 15V, PLL Input, V

Tracking and Margining, 15mm ×

IN

OUT

Step-Down μModule Regulator

15mm × 4.32mm LGA

32V, 2A Step-Down μModule Battery Charger Compatible with Single Cell or Dual Cell Li-Ion or Li-Poly Battery Stacks (4.1V, 4.2V,

with Programmable Input Current Limit

8.2V, or 8.4V), 4.95V ≤ V ≤ 32V, C/10 or Adjustable Timer Charge Termination, NTC

IN

Resistor Monitor Input, 9mm × 15mm × 4.32mm LGA

LTM8045

LTM8048

Inverting or SEPIC μModule DC/DC

2.8V ≤ V ≤ 18V, 2.5V ≤ V

≤ 15V, Synchronizable, No Derating or Logic Level Shift

IN

OUT

Converter with Up to 700mA Output Current for Control Inputs When Inverting, 6.25mm × 11.25mm × 4.92mm BGA

1.5W, 725VDC Galvanically Isolated µModule 3.1V ≤ V ≤ 32V, 2.5V ≤ V

Converter with LDO Post Regulator

≤ 12V, 1mV Output Ripple, Internal Isolated

P-P

IN

OUT

Transformer, 9mm × 11.25mm × 4.92mm BGA

LTC2977

LTC2974

8-Channel PMBus Power System Manager

4-Channel PMBus Power System Manager

0.25% TUE 16-Bit ADC, Voltage/Temperature Monitoring and Supervision

0.25% TUE 16-Bit ADC, Voltage/Current/Temperature Monitoring and Supervision

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This product contains technology licensed from Silicon Semiconductor Corporation.

LT 0514 REV E • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

26

For more information www.linear.com/LTM4600HV

(408)432-1900 FAX: (408) 434-0507 www.linear.com/LTM4600HV

●

 LINEAR TECHNOLOGY CORPORATION 2005


型号：	LTM4600HVMPV#PBF
厂家：	Linear
描述：	LTM4600HV - 10A, 28VIN High Efficiency DC/DC µModule (Power Module); Package: LGA; Pins: 104; Temperature Range: -55°C to 125°C 开关
文件：	总26页 (文件大小：442K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTM4600HVMPV#PBF [Linear]

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