LTC3769

60V Low I

Q

Synchronous

Boost Controller

FEATURES

n

DESCRIPTION

The

LTC

®

3769

is a high performance single output syn-

chronous boost converter controller that drives an all

N-channel power MOSFET stage. Synchronous rectifica-

tion increases efficiency, reduces power losses and eases

thermal requirements, simplifying high power boost ap-

plications. The 28µA no-load quiescent current extends

operating run time in battery-powered systems.

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 LTC3769 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.

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, Burst Mode, OPTI-LOOP Linear Technology and the Linear logo are registered

,

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, 6177787, 6498466, 6580258, 6611131.

n

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: 4µA

Internal LDO Powers Gate Drive from VBIAS or EXTV

CC

Thermally Enhanced Low Profile 24-Pin 4mm × 4mm

QFN Package and 20-Lead TSSOP Package

APPLICATIONS

n

Industrial

Automotive

Medical

Military

TYPICAL APPLICATION

120W, 12V to 24V/5A Synchronous Boost Converter

V

IN

4.5V TO 60V

DOWN TO 2.3V

AFTER START-UP IF

VBIAS IS POWERED

FROM V

OUT

22µF

10nF

15nF

8.66K

100pF

PLLIN/MODE

FREQ

OVMODE

ILIM

PGOOD

GND

INTV

CC

VFB

EXTV

CC

3769 TA01a

Efficiency and Power Loss

vs Output Current

220µF

V

OUT

24V/5A

100

90

EFFICIENCY

EFFICIENCY (%)

V

OUT

FOLLOWS V

IN

FOR V

IN

> 24V

80

70

60

0.01

50

40

0.0001

0.001

POWER

LOSS

0.1

1

POWER LOSS (W)

10

4m

3.3µH

VBIAS

RUN

SS

LTC3769

ITH

SENSE

+

SENSE

–

BG

TG

SW

0.1µF

BOOST

0.1

1

0.001

0.01

OUTPUT CURRENT (A)

10

3769 TA01b

4.7µF

232k

12.1k

3769fa

For more information

www.linear.com/LTC3769

1

LTC3769

ABSOLUTE MAXIMUM RATINGS

(Notes 1, 3)

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

BOOST ........................................................–0.3V to 71V

SW ................................................................ –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

, (BOOST - SW) ..................................–0.3V to 6V

EXTV

CC

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

SENSE

+

, SENSE

–

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

(SENSE

+

- SENSE

–

) ............................................–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

INTV

CC

BOOST

GND

TOP VIEW

ILIM

INTV

CC

FREQ

GND

PLLIN/MODE

RUN

SS

SENSE

–

SENSE

+

1

2

3

4

5

6

7

8

9

21

GND

20 PGOOD

19 VBIAS

18 EXTV

CC

17 INTV

CC

16 BG

15 BOOST

14 TG

13 SW

12 OVMODE

11 ITH

VBIAS 1

PGOOD 2

ILIM 3

NC 4

INTV

CC

5

NC 6

7

FREQ

8

GND

9 10 11 12

PLLIN/MODE

GND

RUN

SS

25

GND

EXTV

CC

BG

24 23 22 21 20 19

18 SW

17 OVMODE

16 ITH

15 VFB

14 SENSE

+

13 SENSE

–

VFB 10

FE PACKAGE

20-LEAD PLASTIC TSSOP

T

JMAX

= 150°C,

θ

JA

= 38°C/W

EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB

UF PACKAGE

24-LEAD (4mm

×

4mm) PLASTIC QFN

T

JMAX

= 150°C,

θ

JA

= 47°C/W

EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB

ORDER INFORMATION

LEAD FREE FINISH

LTC3769EUF#PBF

LTC3769IUF#PBF

LTC3769HUF#PBF

LTC3769MPUF#PBF

LTC3769EFE#PBF

LTC3769IFE#PBF

LTC3769HFE#PBF

LTC3769MPFE#PBF

TAPE AND REEL

LTC3769EUF#TRPBF

LTC3769IUF#TRPBF

LTC3769HUF#TRPBF

LTC3769MPUF#TRPBF

LTC3769EFE#TRPBF

LTC3769IFE#TRPBF

LTC3769HFE#TRPBF

LTC3769MPFE#TRPBF

PART MARKING*

3769

LTC3769FE

PACKAGE DESCRIPTION

24-Lead (4mm

×

4mm) Plastic QFN

24-Lead (4mm

×

4mm) Plastic QFN

24-Lead (4mm

×

4mm) Plastic QFN

24-Lead (4mm

×

4mm) Plastic QFN

20-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/

3769fa

2

For more information

www.linear.com/LTC3769

TG

LTC3769

ELECTRICAL CHARACTERISTICS

SYMBOL

PARAMETER

Main Control Loop

VBIAS

Chip Bias Voltage Operating Range

SENSE Pins Common Mode Range (BOOST

V

IN

Converter Input Supply Voltage)

Regulated Output Voltage Range

V

OUT

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

V

IN

1.188

TYP

MAX

60

60V

1.212

±50

0.02

0.1

–0.1

UNITS

V

nA

%/V

%

mmho

mA

µA

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

SW

= 12V; V

BOOST

= 16.5V;

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

= 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

1.200

±5

0.002

0.01

–0.01

2

0.9

28

4

700

I

Q

Error Amplifier Transconductance

Input DC Supply Current (VBIAS Pin)

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

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

SENSE(MAX)

l

7

90

68

42

4.1

3.8

1.28

100

4.5

0.5

10

100

75

50

200

20

1.2

30

96

110

4.3

1.38

13

110

82

56

300

±1

C

LOAD

= 3300pF (Each Driver)

C

LOAD

= 3300pF (Each Driver)

V

mV

µA

mV

µA

ns

Ω

ns

%

ns

t

ON(MIN)

(Note 7)

3769fa

For more information

www.linear.com/LTC3769

3

LTC3769

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

SW

= 12V; V

BOOST

– V

SW

= 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

= 0

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

BOOST 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 LTC3769 is tested under pulsed load conditions such that

T

J

≈ T

A

. The LTC3769E 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

LTC3769I is guaranteed over the –40°C to 125°C operating junction

temperature range, the LTC3769H is guaranteed over the –40°C to 150°C

operating temperature range and the LTC3769MP 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

= 47°C/W for the QFN package

and

θ

JA

= 38°C/W for the TSSOP 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 LTC3769 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.

3769fa

4

For more information

www.linear.com/LTC3769

LTC3769

TYPICAL PERFORMANCE CHARACTERISTICS

Efficiency and Power Loss

vs Output Current

100

90

80

EFFICIENCY (%)

70

60

50

40

30

20

10

0

0.01

0.1

1

POWER LOSS (W)

10

T

A

= 25°C unless otherwise noted.

Efficiency and Power Loss

vs Output Current

100

90

EFFICIENCY

EFFICIENCY (%)

80

70

60

POWER

LOSS

10

1

POWER LOSS (W)

0.1

V

IN

= 12V

0.01

V

OUT

= 24V

FIGURE 8 CIRCUIT

FCM EFFICIENCY

0.001

FCM LOSS

PULSE-SKIPPING EFFICIENCY

PULSE-SKIPPING LOSS

0.0001

0.1

1

10

OUTPUT CURRENT (A)

3769 G01

0.01

50

40

0.0001

V

IN

= 12V

V

OUT

= 24V

FIGURE 8 CIRCUIT

0.1

1

0.001

0.01

OUTPUT CURRENT (A)

10

3769 G02

0.001

Efficiency vs Input Voltage

100

99

98

EFFICIENCY (%)

97

96

95

94

93

0

5

10

15

20

25

3769 G03

Load Step

Forced Continuous Mode

LOAD STEP

2A/DIV

INDUCTOR

CURRENT

5A/DIV

V

OUT

500mV/DIV

V

IN

= 12V

200µs/DIV

V

OUT

= 24V

LOAD STEP FROM 200mA TO 2.5A

FIGURE 8 CIRCUIT

3769 G04

Load Step

Burst Mode Operation

LOAD STEP

2A/DIV

INDUCTOR

CURRENT

5A/DIV

V

OUT

500mV/DIV

3769 G05

I

LOAD

= 2A

FIGURE 8 CIRCUIT

V

OUT

= 12V

V

OUT

= 24V

V

IN

= 12V

200µs/DIV

V

OUT

= 24V

LOAD STEP FROM 200mA TO 2.5A

FIGURE 8 CIRCUIT

INPUT VOLTAGE (V)

Load Step

Pulse-Skipping Mode

LOAD STEP

2A/DIV

INDUCTOR

CURRENT

5A/DIV

V

OUT

500mV/DIV

3769 G06

Inductor Currents at Light Load

FORCED

CONTINUOUS

MODE

Burst Mode

OPERATION

5A/DIV

PULSE-

SKIPPING MODE

Soft Start-Up

V

OUT

5V/DIV

V

IN

= 12V

200µs/DIV

V

OUT

= 24V

LOAD STEP FROM 200mA TO 2.5A

FIGURE 8 CIRCUIT

V

IN

= 12V

5µs/DIV

V

OUT

= 24V

I

LOAD

= 200µA

FIGURE 8 CIRCUIT

3769 G07

V

RUN

5V/DIV

0V

20ms/DIV

V

IN

= 12V

V

OUT

= 24V

FIGURE 8 CIRCUIT

3769 G08

3769fa

For more information

www.linear.com/LTC3769

5

参数名称	属性值
输出类型	晶体管驱动器
功能	升压，升压/降压
输出配置	正
拓扑	升压，SEPIC
输出数	1
输出阶段	1
电压 - 电源（Vcc/Vdd）	4.5 V ~ 60 V
频率 - 开关	105kHz ~ 760kHz
占空比（最大）	0.96
同步整流器	是
时钟同步	无
控制特性	限流，使能，频率控制，电源良好，软启动
工作温度	-40°C ~ 150°C（TJ）
封装/外壳	24-WFQFN 裸露焊盘
供应商器件封装	24-QFN（4x4）

LTC3769HUF#TRPBF

LTC3769HUF#TRPBF概述

LTC3769HUF#TRPBF规格参数

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