LTC3411AIDD-TRPBF,LTC3411AIDD-TRPBF pdf中文资料,LTC3411AIDD-TRPBF引脚图,LTC3411AIDD-TRPBF电路-Datasheet-电子工程世界

LTC3411A

1.25A, 4MHz, Synchronous

Step-Down DC/DC Converter

FEATURES

■

DESCRIPTION

The LTC

®

3411A is a constant frequency, synchronous

step-down DC/DC converter. Intended for medium power

applications, it operates from a 2.5V to 5.5V input voltage

range and has a user conﬁgurable operating frequency

up to 4MHz, allowing the use of tiny, low cost capacitors

and inductors 1mm or less in height. The output voltage is

adjustable from 0.8V to 5.5V. Internal synchronous power

switches provide high efﬁciency. The LTC3411A’s current

mode architecture and external compensation allow the

transient response to be optimized over a wide range of

loads and output capacitors.

The LTC3411A can be conﬁgured for automatic power

saving Burst Mode operation (I

Q

= 40μA) to reduce gate

charge losses when the load current drops below the level

required for continuous operation. For reduced noise and

RF interference, the SYNC/MODE pin can be conﬁgured to

skip pulses or provide forced continuous operation.

To further maximize battery life, the P-channel MOSFET

is turned on continuously in dropout (100% duty cycle).

In shutdown, the device draws <1μA.

L,

LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology

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

U.S. Patents including 5481178, 6580258, 6498466, 6611131.

■

Uses Tiny Capacitors and Inductor

High Frequency Operation: Up to 4MHz

Low R

DS(ON)

Internal Switches: 0.15Ω

High Efﬁciency: Up to 96%

Selectable Low Ripple (25mV

P-P

) Burst Mode

®

Operation: I

Q

= 40μA

Stable with Ceramic Capacitors

Current Mode Operation for Excellent Line

and Load Transient Response

Short-Circuit Protected

Low Dropout Operation: 100% Duty Cycle

Low Shutdown Current: I

Q

≤ 1μA

Output Voltages from 0.8V to 5V

Synchronizable to External Clock

Supports Pre-Biased Outputs

Small 10-Lead 3mm

×

3mm DFN or MSOP Package

APPLICATIONS

■

Notebook Computers

Digital Cameras

Cellular Phones

Handheld Instruments

Board Mounted Power Supplies

TYPICAL APPLICATION

Step-Down 2.5V/1.25A Regulator

V

IN

2.5V TO 5.5V

10μF

SYNC

SYNC/MODE

PGOOD

LTC3411A

PV

IN

SV

IN

SW

22pF

2.2μH

V

OUT

2.5V

1.25A

Efﬁciency and Power Loss vs Output Current

100

90

80

EFFICIENCY (%)

70

60

50

40

30

0.01

0.1

POWER LOSS (W)

1

I

TH

12.1k

680pF

549k

SHDN/R

T

SGND

PGND

V

FB

887k

22μF

20

10

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 4.2V

1

100

1000

10

OUTPUT CURRENT (mA)

0.001

412k

0

0.1

0.0001

10000

3411a TA01a

f

O

= 1MHz

Burst Mode OPERATION

3411A TA01b

3411afa

1

LTC3411A

ABSOLUTE MAXIMUM RATINGS

(Note 1)

PV

IN

, SV

IN

Voltages ..................................... –0.3V to 6V

V

FB

, I

TH

, SHDN/R

T

Voltages ..........–0.3V to (V

IN

+ 0.3V)

SYNC/MODE Voltage .....................–0.3V to (V

IN

+ 0.3V)

SW Voltage ..................................–0.3V to (V

IN

+ 0.3V)

PGOOD Voltage ........................................... –0.3V to 6V

Operating Junction Temperature Range

(Notes 2, 5, 8) ........................................ –40°C to 125°C

Storage Temperature Range................... –65°C to 125°C

Lead Temperatu re (Soldering, 10 sec) ............... 300°C

PIN CONFIGURATION

TOP VIEW

SHDN/R

T

SYNC/MODE

SGND

SW

PGND

1

2

3

4

5

11

10 I

TH

9 V

FB

8 PGOOD

7 SV

IN

6 PV

IN

SHDN/R

T

SYNC/MODE

SGND

SW

PGND

1

2

3

4

5

TOP VIEW

10

9

8

7

6

I

TH

V

FB

PGOOD

SV

IN

PV

IN

DD PACKAGE

10-LEAD (3mm × 3mm) PLASTIC DFN

T

JMAX

= 125°C,

θ

JA

= 43°C/W,

θ

JC

= 3°C/W

EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB

MS PACKAGE

10-LEAD PLASTIC MSOP

T

JMAX

= 125°C,

θ

JA

= 120°C/W,

θ

JC

= 10°C/W

ORDER INFORMATION

LEAD FREE FINISH

LTC3411AEDD#PBF

LTC3411AIDD#PBF

LTC3411AEMS#PBF

LTC3411AIMS#PBF

TAPE AND REEL

LTC3411AEDD#TRPBF

LTC3411AIDD#TRPBF

LTC3411AEMS#TRPBF

LTC3411AIMS#TRPBF

PART MARKING*

LAJM

LTAJK

PACKAGE DESCRIPTION

10-Lead (3mm × 3mm) Plastic DFN

10-Lead Plastic MSOP

TEMPERATURE RANGE

–40°C to 125°C

Consult LTC Marketing for parts speciﬁed with wider operating temperature ranges. *Temperature grades are identiﬁed by a label on the shipping container.

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/

The

●

denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T

A

= 25°C, V

IN

= 3.6V, R

T

= 125k unless otherwise speciﬁed. (Note 2)

SYMBOL

V

IN

I

FB

V

FB

ΔV

LINEREG

ΔV

LOADREG

g

m(EA)

PARAMETER

Operating Voltage Range

Feedback Pin Input Current

Feedback Voltage

Reference Voltage Line Regulation

Output Voltage Load Regulation

Error Ampliﬁer Transconductance

(Note 3)

V

IN

= 2.5V to 5.5V

I

TH

= 0.55V to 0.9V

I

TH

Pin Load = ±5μA (Note 3)

●

ELECTRICAL CHARACTERISTICS

CONDITIONS

●

MIN

2.5

0.784

TYP

MAX

5.5

±0.1

UNITS

V

μA

V

%/V

%

μS

3411afa

0.8

0.04

0.02

300

0.816

0.2

2

LTC3411A

ELECTRICAL CHARACTERISTICS

SYMBOL

I

S

PARAMETER

Input DC Supply Current (Note 4)

Active Mode

Sleep Mode

Shutdown

Shutdown Threshold High Active

Oscillator Resistor

Oscillator Frequency

Synchronization Frequency

Peak Switch Current Limit

Top Switch On-Resistance

Bottom Switch On-Resistance

I

SW(LKG)

V

UVLO

PGOOD

Switch Leakage Current

Undervoltage Lockout Threshold

Power Good Threshold

Power Bad Threshold

R

PGOOD

PGOOD Blanking

V

SYNC-MODE

t

SOFT-START

Pulse Skip

Force Continous

Burst

10% to 90% of Regulation

Power Good Pull-Down On-Resistance

V

FB

Step from 0V to 0.8V

V

FB

Step from 0.8V to 0V

0.93

V

IN

– 0.75

0.5

The

●

denotes the speciﬁcations which apply over the full operating

temperature range, otherwise speciﬁcations are at T

A

= 25°C, V

IN

= 3.6V, R

T

= 125k unless otherwise speciﬁed. (Note 2)

CONDITIONS

V

SYNC/MODE

= 3.6V, V

FB

= 0.75V

V

SYNC/MODE

= 3.6V, V

FB

= 0.84V

V

SHDN/RT

= 3.6V

MIN

TYP

330

40

0.1

V

IN

– 0.6

125k

2.5

MAX

450

60

1

V

IN

– 0.4

1M

2.8

4

2.6

0.18

0.16

1

2.4

UNITS

μA

V

Ω

MHz

A

Ω

μA

V

%

Ω

μs

V

ms

V

SHDN/RT

f

OSC

f

SYNC

I

LIM

R

DS(ON)

R

T

= 125k

(Note 7)

V

FB

= 0.5V

MS Package

DD Package (Note 6)

MS Package

DD Package (Note 6)

V

IN

= 5.5V, V

SHDN/RT

= 5.5V, V

SW

= 0V

or 5.5V

V

IN

Ramping Down

V

FB

Ramping Up from 0.68V to 0.8V

V

FB

Ramping Down from 0.92V to 0.8V

V

FB

Ramping Down from 0.8V to 0.68V

V

FB

Ramping Up from 0.8V to 0.9V

2.25

0.4

1.6

2.1

0.15

0.13

0.01

1.8

–5

5

2.1

–7

7

–10

10

15

40

105

–12

12

30

0.63

V

IN

– 1.05

0.8

1.0

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 LTC3411AE is guaranteed to meet performance 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

LTC3411AI is guaranteed over the full –40°C to 125°C operating junction

temperature range.

Note 3:

The LTC3411A is tested in a feedback loop which servos V

FB

to

the midpoint for the error ampliﬁer (V

ITH

= 0.7V).

Note 4:

Dynamic supply current is higher due to the internal gate charge

being delivered at the switching frequency.

Note 5:

T

J

is calculated from the ambient T

A

and power dissipation P

D

according to the following formulas:

LTC3411AEDD: T

J

= T

A

+ (P

D

• 43°C/W)

LTC3411AEMS: T

J

= T

A

+ (P

D

• 120°C/W)

Note 6:

For the DD package, switch on-resistance is sampled at wafer

level measurements and assured by design, characterization and

correlation with statistical process controls.

Note 7:

4MHz operation is guaranteed by design but not production

tested and is subject to duty cycle limitations (see Applications

Information).

Note 8:

This IC includes overtemperature protection that is intended

to protect the device during momentary overload conditions. Junction

temperature will exceed 125°C when overtemperature protection is

active. Continuous operation above the speciﬁed maximum operating

junction temperature may impair device reliability.

3411afa

3

LTC3411A

TYPICAL PERFORMANCE CHARACTERISTICS

otherwise noted.

Efﬁciency vs Input Voltage

100

I

OUT

= 100mA

90

80

EFFICIENCY (%)

70

60

50

40

V

OUT

= 1.8V

30

2.5

3.0

4.5

4.0

3.5

INPUT VOLTAGE(V)

5.0

5.5

I

OUT

= 0.1mA

I

OUT

= 1mA

EFFICIENCY (%)

I

OUT

= 1.25A

I

OUT

= 10mA

100

90

80

EFFICIENCY (%)

70

60

50

40

30

20

10

0

0.1

V

OUT

= 1.8V

1

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 4.2V

10000

3411A G02

T

A

= 25°C, V

IN

= 3.6V, f

O

= 1MHz, unless

Efﬁciency vs Output Current

100

90

80

70

60

50

40

30

20

10

Efﬁciency vs Output Current

100

1000

10

OUTPUT CURRENT (mA)

0

0.1

V

OUT

= 1.5V

1

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 4.2V

10000

3411A G03

10

100

1000

OUTPUT CURRENT (mA)

3411A G01

Efﬁciency vs Output Current

100

90

80

EFFICIENCY (%)

Burst Mode

OPERATION

95

94

93

Efﬁciency vs Frequency

1.00

4.7μH

0.75

2.2μH

92

91

90

89

1μH

V

OUT

= 1.8V

I

LOAD

= 400mA

0

1

3

2

FREQUENCY (MHz)

4

5

3411A G05

Load Regulation

V

OUT

ERROR (%)

70

60

50

40

30

20

10

0

0.1

PULSE

SKIP

0.50

Burst Mode OPERATION

0.25

PULSE SKIP

0.00

FORCED CONTINUOUS

–0.25

V

OUT

= 1.8V

–0.50

0

200

400 600 800 1000 1200 1400

OUTPUT CURRENT(mA)

3411A

G06

V

OUT

= 1.8V

1

10

100

1000

OUTPUT CURRENT (mA)

10000

3411A G04

88

Line Regulation

0.6

0.4

V

OUT

ERROR (%)

0.2

0.0

–0.2

–0.4

–0.6

2.5

815

Reference Voltage vs

Temperature

6

V

IN

= 3.6V

FREQUENCY VARIATION (%)

–25

50

25

75

0

TEMPERATURE(°C)

100

125

REFERENCE VOLTAGE (mV)

810

805

800

795

790

785

–50

4

2

0

–2

–4

Frequency Variation vs

Temperature

V

OUT

= 1.8V

I

LOAD

= 400mA

3.0

4.5

4.0

3.5

INPUT VOLTAGE(V)

5.0

5.5

3411A G07

–6

–50

–25

50

25

75

0

TEMPERATURE(°C)

100

125

3411A G08

3411A G09

3411afa

4

LTC3411A

TYPICAL PERFORMANCE CHARACTERISTICS

otherwise noted.

Frequency Variation vs V

IN

6

4

FREQUENCY VARIATION (%)

2

R

DS(ON)

(Ω)

0

–2

–4

0.05

–6

–8

2.5

0.0

2.5

MAIN SWITCH

SYNCHRONOUS SWITCH

3.0

3.5

4.0

V

IN

(V)

4.5

5.0

5.5

3411A G10

T

A

= 25°C, V

IN

= 3.6V, f

O

= 1MHz, unless

R

DS(ON)

vs Input Voltage

0.25

0.30

0.25

0.20

0.15

0.10

0.05

R

DS(ON)

vs Temperature

0.20

0.15

0.10

R

DS(ON)

(Ω)

MAIN SWITCH

SYNCHRONOUS SWITCH

–25

50

25

75

0

TEMPERATURE (°C)

100

125

3.0

4.5

4.0

3.5

INPUT VOLTAGE (V)

5.0

5.5

3411A G11

0.0

–50

3411A G12

Dynamic Supply Current vs Input

Voltage

100

DYNAMIC SUPPLY CURRENT (mA)

100

FORCED CONTINUOUS

Dynamic Supply Current vs

Temperature

2500

Switch Leakage vs Input Voltage

10

FORCED CONTINUOUS

SWITCH LEAKAGE (pA)

2000

MAIN SWITCH

1500

1

PULSE SKIP

0.1

Burst Mode

OPERATION

1

PULSE SKIP

0.1

Burst Mode

OPERATION

1000

SYNCHRONOUS SWITCH

0.01

V

OUT

= 1.8V

I

LOAD

= 0A

3.0

3.5

4.0

V

IN

(V)

4.5

5.0

5.5

0.01

V

OUT

= 1.8V

I

LOAD

= 0A

500

0.001

2.5

0.001

–50

0

–25

0

25

50

75

TEMPERATURE (°C)

100

125

0

1

4

3

2

INPUT VOLTAGE(V)

5

6

3411A G15

3411A G13

3411A G14

Switch Leakage vs Temperature

600

500

SWITCH LEAKAGE (nA)

400

300

200

100

0

–50

MAIN SWITCH

SYNCHRONOUS SWITCH

SW

2V/DIV

V

OUT

50mV/DIV

AC COUPLED

I

L

200mA/DIV

Burst Mode Operation

SW

2V/DIV

V

OUT

50mV/DIV

AC COUPLED

I

L

200mA/DIV

4μs/DIV

V

IN

= 3.6V

V

OUT

= 1.8V

I

LOAD

= 50mA

3411A G17

Pulse Skippng Mode

4μs/DIV

V

IN

= 3.6V

V

OUT

= 1.8V

I

LOAD

= 5mA

3411A G18

–25

50

25

75

0

TEMPERATURE (°C)

100

125

3411A G16

3411afa

5

LTC3411AIDD-TRPBF

LTC3411AIDD-TRPBF概述

文档预览

LTC3411AIDD-TRPBF相似产品对比

推荐资源