LTC3784HGN#PBF datasheet, PDF - EEWORLD Datasheet

FeaTures

n

LTC3784

60V PolyPhase Synchronous

Boost Controller

DescripTion

The

LTC

®

3784

is a high performance PolyPhase

®

single

output synchronous boost converter controller that drives

two N-channel power MOSFET stages out-of-phase.

Multiphase operation reduces input and output capacitor

requirements and allows the use of smaller inductors than

the single-phase equivalent. Synchronous rectification in-

creases efficiency, reduces power losses and eases thermal

requirements, simplifying high power boost applications.

A 4.5V to 60V input supply range encompasses a wide

range of system architectures and battery chemistries.

When biased from the output of the boost converter or

another auxiliary supply, the LTC3784 can operate from an

input supply as low as 2.3V after start-up. The operating

frequency can be set within a 50kHz to 900kHz range or

synchronized to an external clock using the internal PLL.

PolyPhase operation allows the LTC3784 to be configured

for 2-, 3-, 4-, 6- and 12-phase operation.

The SS pin ramps the output voltage during start-up. The

PLLIN/MODE pin selects Burst Mode

®

operation, pulse-

skipping mode or forced continuous mode at light loads.

L,

LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode, OPTI-LOOP and PolyPhase

are registered trademarks and No R

SENSE

and ThinSOT are trademarks of Linear Technology

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

U. S. Patents, including 5408150, 5481178, 5705919, 5929620, 6144194, 6177787, 6580258.

n

PolyPhase

®

Operation Reduces Required Input and

Output Capacitance and Power Supply Induced Noise

Synchronous Operation for Highest Efficiency and

Reduced Heat Dissipation

Wide V

IN

Range: 4.5V to 60V (65V Abs Max);

Operates Down to 2.3V After Start-Up

Output Voltage Up to 60V

±1% 1.200V Reference Voltage

R

SENSE

or Inductor DCR Current Sensing

100% Duty Cycle Capability for Synchronous MOSFET

Low Quiescent Current: 28μA

Phase-Lockable Frequency (75kHz to 850kHz)

Programmable Fixed Frequency (50kHz to 900kHz)

Power Good Output Voltage Monitor

Low Shutdown Current, I

Q

< 4µA

Internal LDO Powers Gate Drive from VBIAS or EXTV

CC

Thermally Enhanced Low Profile 28-Pin 4mm × 5mm

QFN Package and Narrow SSOP Package

applicaTions

n

Industrial

Automotive

Medical

Military

Typical applicaTion

240W, 12V to 24V/10A 2-Phase Synchronous Boost Converter

4m

47µF

SENSE1

+

SENSE1

–

BG1

BOOST1

VBIAS

SW1

LTC3784

TG1

INTV

CC

0.1µF

V

OUT

24V AT 10A

220µF

3.3µH

Efficiency and Power Loss

vs Output Current

100

90

80

EFFICIENCY (%)

70

60

50

40

30

20

10

BURST EFFICIENCY

BURST LOSS

V

IN

= 12V

V

OUT

= 24V

Burst Mode OPERATION

FIGURE 10 CIRCUIT

1

10

3784 TA01b

V

IN

4.5V TO 60V

DOWN TO 2.3V AFTER

STARTUP IF VBIAS IS

POWERED FROM V

OUT

10000

1000

POWER LOSS (mW)

4.7µF

4m

3.3µH

SENSE2

+

SENSE2

–

BG2

BOOST2

FREQ

SW2

OVMODE

TG2

PLLIN/MODE

ITH

VFB

SS

SGND PGND

100pF

0.1µF

V

OUT

FOLLOWS V

IN

FOR V

IN

> 24V

100

10

1

15nF

8.66k

232k

12.1k

3784 TA01a

0

0.1

0.00001 0.0001 0.001 0.01

OUTPUT CURRENT (A)

0.1

3784fb

For more information

www.linear.com/LTC3784

1

LTC3784

absoluTe MaxiMuM raTings

(Notes 1, 3)

VBIAS ........................................................ –0.3V to 65V

BOOST1 and BOOST2 .................................–0.3V to 71V

SW1 and SW2............................................... –5V to 65V

RUN ............................................................. –0.3V to 8V

Maximum Current Sourced into Pin

From Source >8V ..............................................100µA

PGOOD, PLLIN/MODE ................................. –0.3V to 6V

INTV

CC

, (BOOST1 - SW1), (BOOST2 - SW2) ...–0.3V to 6V

EXTV

CC

...................................................... –0.3V to 14V

SENSE1

+

, SENSE1

–

, SENSE2

+

, SENSE2

–

... –0.3V to 65V

(SENSE1

+

- SENSE1

–

), (SENSE2

+

- SENSE2

–

) ...–0.3V to 0.3V

ILIM, SS, ITH, FREQ, PHASMD, VFB ..... –0.3V to INTV

CC

Operating Junction Temperature

Range (Note 2)........................................–55°C to 150°C

Storage Temperature Range .................. –65°C to 150°C

Lead Temperature (Soldering, 10 sec) SSOP ........ 300°C

pin conFiguraTion

TOP VIEW

SENSE1

–

ILIM

SENSE1

+

SENSE1

–

FREQ

PHASMD

CLKOUT

PLLIN/MODE

SGND

RUN

SENSE2

–

1

2

3

4

5

6

7

8

9

11

28 PGOOD

27 SW1

26 TG1

25 BOOST1

24 BG1

23 VBIAS

22 PGND

21 EXTV

CC

20 INTV

CC

19 BG2

18 BOOST2

17 TG2

16 SW2

15 OVMODE

FREQ 1

PHASMD 2

CLKOUT 3

PLLIN/MODE 4

SGND 5

RUN 6

SS 7

SENSE2

–

8

9 10 11 12 13 14

VFB

ITH

OVMODE

SW2

SENSE2

+

TG2

29

GND

TOP VIEW

SENSE1

+

PGOOD

SW1

ILIM

TG1

22 BOOST1

21 BG1

20 VBIAS

19 PGND

18 EXTV

CC

17 INTV

CC

16 BG2

15 BOOST2

28 27 26 25 24 23

SS 10

SENSE2

+

12

VFB 13

ITH 14

GN PACKAGE

28-LEAD PLASTIC SSOP

T

JMAX

= 150°C,

θ

JA

= 80°C/W

UFD PACKAGE

28-LEAD (4mm

×

5mm) PLASTIC QFN

T

JMAX

= 150°C,

θ

JA

= 43°C/W

EXPOSED PAD (PIN 29) IS GND, MUST BE CONNECTED TO GND

orDer inForMaTion

LEAD FREE FINISH

LTC3784EUFD#PBF

LTC3784IUFD#PBF

LTC3784HUFD#PBF

LTC3784MPUFD#PBF

LTC3784EGN#PBF

LTC3784IGN#PBF

LTC3784HGN#PBF

LTC3784MPGN#PBF

TAPE AND REEL

LTC3784EUFD#TRPBF

LTC3784IUFD#TRPBF

LTC3784HUFD#TRPBF

LTC3784MPUFD#TRPBF

LTC3784EGN#TRPBF

LTC3784IGN#TRPBF

LTC3784HGN#TRPBF

LTC3784MPGN#TRPBF

PART MARKING*

3784

LTC3784GN

PACKAGE DESCRIPTION

28-Lead (4mm

×

5mm) Plastic QFN

28-Lead (4mm

×

5mm) Plastic QFN

28-Lead (4mm

×

5mm) Plastic QFN

28-Lead (4mm

×

5mm) Plastic QFN

28-Lead Plastic SSOP

TEMPERATURE RANGE

–40°C to 125°C

–40°C to 150°C

–55°C to 150°C

–40°C to 125°C

–40°C to 150°C

–55°C to 150°C

Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.

For more information on lead free part marking, go to:

http://www.linear.com/leadfree/

For more information on tape and reel specifications, go to:

http://www.linear.com/tapeandreel/

3784fb

2

For more information

www.linear.com/LTC3784

LTC3784

elecTrical characTerisTics

SYMBOL

PARAMETER

Main Control Loop

VBIAS

Chip Bias Voltage Operating Range

SENSE Pins Common Mode Range (BOOST

Converter Input Supply Voltage V

IN

)

Regulated Feedback Voltage

V

FB

Feedback Current

Reference Line Voltage Regulation

Output Voltage Load Regulation

(Note 4)

The

l

denotes the specifications which apply over the specified operating

junction temperature range, otherwise specifications are at T

A

= 25°C, VBIAS = 12V, unless otherwise noted (Note 2).

CONDITIONS

MIN

4.5

2.3

I

TH

= 1.2V (Note 4)

(Note 4)

VBIAS = 6V to 60V

Measured in Servo Loop;

ΔI

TH

Voltage = 1.2V to 0.7V

Measured in Servo Loop;

ΔI

TH

Voltage = 1.2V to 2V

I

TH

= 1.2V

(Note 5)

RUN = 5V; V

FB

= 1.25V (No Load)

RUN = 5V; V

FB

= 1.25V (No Load)

RUN = 0V

V

SW1,2

= 12V; V

BOOST1,2

= 4.5V;

FREQ = 0V, Forced Continuous or

Pulse-Skipping Mode

V

INTVCC

Ramping Up

V

INTVCC

Ramping Down

V

RUN

Rising

V

RUN

> 1.28V

V

RUN

< 1.28V

V

SS

= GND

V

FB

= 1.1V, I

LIM

= INTV

CC

V

FB

= 1.1V, I

LIM

= Float

V

FB

= 1.1V, I

LIM

= GND

V

FB

= 1.1V, I

LIM

= INTV

CC

V

FB

= 1.1V, I

LIM

= Float

V

FB

= 1.1V, I

LIM

= GND

V

FB

= 1.1V, I

LIM

= Float

V

FB

= 1.1V, I

LIM

= Float

C

LOAD

= 3300pF (Note 6)

C

LOAD

= 3300pF (Note 6)

C

LOAD

= 3300pF (Note 6)

C

LOAD

= 3300pF (Note 6)

l

TYP

MAX

60

UNITS

V

nA

%/V

%

mmho

mA

µA

1.188

l

1.200

±5

0.002

0.01

–0.01

2

0.9

28

4

700

1.212

±50

0.02

0.1

–0.1

I

Q

Error Amplifier Transconductance

Input DC Supply Current

Pulse-Skipping or Forced Continuous Mode

Sleep Mode

Shutdown

SW Pin Current

45

10

UVLO

V

RUN

INTV

CC

Undervoltage Lockout Thresholds

RUN Pin ON Threshold

RUN Pin Hysteresis

RUN Pin Hysteresis Current

RUN Pin Current

Soft-Start Charge Current

Maximum Current Sense Threshold

Matching Between V

SENSE1(MAX)

and

V

SENSE2(MAX)

SENSE

+

Pin Current

SENSE

–

Pin Current

Top Gate Rise Time

Top Gate Fall Time

Bottom Gate Rise Time

Bottom Gate Fall Time

Top Gate Pull-Up Resistance

Top Gate Pull-Down Resistance

Bottom Gate Pull-Up Resistance

Bottom Gate Pull-Down Resistance

Top Gate Off to Bottom Gate On Switch-On

Delay Time

Bottom Gate Off to Top Gate On Switch-On

Delay Time

Maximum BG Duty Factor

Minimum BG On-Time

l

3.6

1.18

V

SENSE1,2(MAX)

l

7

90

68

42

–12

–10

–9

4.1

3.8

1.28

100

4.5

0.5

10

100

75

50

0

200

20

1.2

30

96

110

4.3

1.38

13

110

82

56

12

10

9

300

±1

C

LOAD

= 3300pF (Each Driver)

C

LOAD

= 3300pF (Each Driver)

V

mV

µA

mV

µA

ns

Ω

ns

%

ns

3784fb

t

ON(MIN)

(Note 7)

For more information

www.linear.com/LTC3784

3

LTC3784

elecTrical characTerisTics

SYMBOL

PARAMETER

INTV

CC

Linear Regulator

Internal V

CC

Voltage

INTV

CC

Load Regulation

Internal V

CC

Voltage

INTV

CC

Load Regulation

EXTV

CC

Switchover Voltage

EXTV

CC

Hysteresis

Oscillator and Phase-Locked Loop

Programmable Frequency

f

LOW

Lowest Fixed Frequency

Highest Fixed Frequency

Synchronizable Frequency

PGOOD Output

PGOOD Voltage Low

PGOOD Leakage Current

PGOOD Trip Level

I

PGOOD

= 2mA

V

PGOOD

= 5V

V

FB

with Respect to Set Regulated Voltage

V

FB

Ramping Negative

Hysteresis

V

FB

Ramping Positive

Hysteresis

PGOOD Going High to Low

V

FB

Ramping Positive, OVMODE = 0V

V

SW1,2

= 12V; V

BOOST1,2

– V

SW1,2

= 4.5V;

FREQ = 0V, Forced Continuous or

Pulse-Skipping Mode

1.296

–12

8

–10

2.5

10

2.5

45

1.32

55

1.344

0.2

0.4

±1

–8

12

V

µA

%

µs

V

µA

R

FREQ

= 25k

R

FREQ

= 60k

R

FREQ

= 100k

V

FREQ

= 0V

V

FREQ

= INTV

CC

PLLIN/MODE = External Clock

l

The

l

denotes the specifications which apply over the specified operating

junction temperature range, otherwise specifications are at T

A

= 25°C, VBIAS = 12V, unless otherwise noted (Note 2).

CONDITIONS

6V < V

BIAS

< 60V, V

EXTVCC

= 0V

I

CC

= 0mA to 50mA

6V < V

EXTVCC

< 13V

I

CC

= 0mA to 40mA, V

EXTVCC

= 8.5V

EXTV

CC

Ramping Positive

MIN

5.2

l

TYP

5.4

0.5

5.4

0.5

4.8

250

105

400

760

350

535

MAX

5.6

2

5.6

2

5

UNITS

V

%

V

%

V

mV

kHz

4.5

335

320

488

75

465

380

585

850

PGOOD Delay

OV Protection Threshold

BOOST1 and BOOST2 Charge Pump

BOOST Charge Pump Available Output

Current

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 LTC3784 is tested under pulsed load conditions such that

T

J

≈ T

A

. The LTC3784E is guaranteed to meet specifications from

0°C to 85°C junction temperature. Specifications over the –40°C to

125°C operating junction temperature range are assured by design,

characterization and correlation with statistical process controls. The

LTC3784I is guaranteed over the –40°C to 125°C operating junction

temperature range, the LTC3784H is guaranteed over the –40°C to 150°C

operating temperature range and the LTC3784MP is tested and guaranteed

over the full –55°C to 150°C operating junction temperature range. High

junction temperatures degrade operating lifetimes; operating lifetime

is derated for junction temperatures greater than 125°C. Note that the

maximum ambient temperature consistent with these specifications is

determined by specific operating conditions in conjunction with board

layout, the rated package thermal impedance and other environmental

factors. The junction temperature (T

J

, in °C) is calculated from the ambient

temperature (T

A

, in °C) and power dissipation (P

D

, in Watts) according to

the formula: T

J

= T

A

+ (P

D

•

θ

JA

), where

θ

JA

= 43°C/W for the QFN package

and

θ

JA

= 80°C/W for the SSOP package.

Note 3:

This IC includes overtemperature protection that is intended to

protect the device during momentary overload conditions. The maximum

rated junction temperature will be exceeded when this protection is active.

Continuous operation above the specified absolute maximum operating

junction temperature may impair device reliability or permanently damage

the device.

Note 4:

The LTC3784 is tested in a feedback loop that servos V

FB

to the

output of the error amplifier while maintaining I

TH

at the midpoint of the

current limit range.

Note 5:

Dynamic supply current is higher due to the gate charge being

delivered at the switching frequency.

Note 6:

Rise and fall times are measured using 10% and 90% levels. Delay

times are measured using 50% levels.

Note 7:

see Minimum On-Time Considerations in the Applications

Information section.

3784fb

4

For more information

www.linear.com/LTC3784

LTC3784

Typical perForMance characTerisTics

Efficiency and Power Loss

vs Output Current

100

90

80

EFFICIENCY (%)

70

60

50

40

30

20

10

0

0.01

V

IN

= 12V

V

OUT

= 24V

FIGURE 10 CIRCUIT

0.1

1

OUTPUT CURRENT (A)

10

1

10

100

1000

POWER LOSS (mW)

EFFICIENCY (%)

10000

100

90

80

70

60

50

40

30

10

100

1000

POWER LOSS (mW)

EFFICIENCY (%)

T

A

= 25°C unless otherwise noted.

Efficiency vs Load Current

100

99

98

97

96

95

94

93

92

91

90

0

5

15

10

INPUT VOLTAGE (V)

20

25

3784 G03

Efficiency and Power Loss

vs Output Current

10000

V

IN

= 12V

I

LOAD

= 2A

FIGURE 10 CIRCUIT

V

OUT

= 12V

V

OUT

= 24V

0.1

3784 G01

V

IN

= 12V

20

1

V

OUT

= 24V

10

Burst Mode OPERATION

FIGURE 10 CIRCUIT

0

0.1

1

10

0.00001 0.0001 0.001 0.01

OUTPUT CURRENT (A)

3784 G02

BURST EFFICIENCY

PULSE-SKIPPING

EFFICIENCY

FORCED CONTINUOUS

MODE EFFICIENCY

BURST LOSS

PULSE-SKIPPING

LOSS

FORCED CONTINUOUS

MODE LOSS

BURST EFFICIENCY

BURST LOSS

Load Step

Forced Continuous Mode

LOAD STEP

5A/DIV

LOAD STEP

5A/DIV

INDUCTOR

CURRENT

5A/DIV

V

OUT

500mV/DIV

Load Step

Burst Mode Operation

LOAD STEP

5A/DIV

Load Step

Pulse-Skipping Mode

INDUCTOR

CURRENT

5A/DIV

V

OUT

500mV/DIV

INDUCTOR

CURRENT

5A/DIV

V

OUT

500mV/DIV

200µs/DIV

V

IN

= 12V

V

OUT

= 24V

LOAD STEP FROM 100mA TO 5A

FIGURE 10 CIRCUIT

3784 G05

200µs/DIV

V

IN

= 12V

V

OUT

= 24V

LOAD STEP FROM 100mA TO 5A

FIGURE 10 CIRCUIT

3784 G04

200µs/DIV

V

IN

= 12V

V

OUT

= 24V

LOAD STEP FROM 100mA TO 5A

FIGURE 10 CIRCUIT

3784 G06

Inductor Currents at Light Load

Soft Start-Up

1.212

REGULATED FEEDBACK VOLTAGE (V)

1.209

1.206

1.203

1.200

1.197

1.194

1.191

Regulated Feedback Voltage

vs Temperature

FORCED

CONTINUOUS

MODE

V

OUT

5V/DIV

Burst Mode

OPERATION

5A/DIV

PULSE-

SKIPPING

MODE

0V

5µs/DIV

V

IN

= 12V

V

OUT

= 24V

I

LOAD

= 200µA

FIGURE 10 CIRCUIT

3784 G07

2ms/DIV

V

IN

= 12V

V

OUT

= 24V

FIGURE 10 CIRCUIT

3784 G08

1.188

–60 –35 –10 15 40 65 90 115 140

TEMPERATURE (°C)

3784 G09

3784fb

For more information

www.linear.com/LTC3784

5

Parameter Name	Attribute value
EU restricts the use of certain hazardous substances	Compliant
ECCN (US)	EAR99
Part Status	Active
HTS	8542.39.00.01
Number of Outputs	1
Topology	Step Up
Output Voltage (V)	60(Max)
Maximum Switching Frequency (kHz)	900
Minimum Input Voltage (V)	4.5
Maximum Input Voltage (V)	60
Operating Supply Voltage (V)	4.5 to 60
Maximum Supply Current (mA)	0.9(Typ)
Typical Quiescent Current (mA)	0.028
Typical Gate Driver Pull Up Resistance (Ohm)	1.2/1.2
Typical Gate Driver Pull Down Resistance (Ohm)	1.2/1.2
Minimum Switching Frequency (kHz)	50
Minimum Operating Temperature (°C)	-40
Maximum Operating Temperature (°C)	150
Supplier Temperature Grade	Automotive
Packaging	Tube
Pin Count	28
Standard Package Name	SOP
Supplier Package	SSOP N
Mounting	Surface Mount
Package Height	1.5(Max)
Package Length	9.98(Max)
Package Width	3.99(Max)
PCB changed	28
Lead Shape	Gull-wing

LTC3784HGN#PBF

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