LTC3619BIDD#TRPBF datasheet, PDF

FeaTures

n

Programmable Average Input Current Limit:

±5% Accuracy

Dual Step-Down Outputs: Up to 96% Efficiency

Low Noise Pulse-Skipping Operation at Light Loads

Input Voltage Range: 2.5V to 5.5V

Output Voltage Range: 0.6V to 5V

2.25MHz Constant-Frequency Operation

Power Good Output Voltage Monitor for Each Channel

Low Dropout Operation: 100% Duty Cycle

Independent Internal Soft-Start for Each Channel

Current Mode Operation for Excellent Line and Load

Transient Response

±2% Output Voltage Accuracy

Short-Circuit Protected

Shutdown Current ≤ 1μA

Available in Small Thermally Enhanced 10-Lead MS

and 3mm

×

3mm DFN Packages

High Peak Load Current Applications

USB Powered Devices

Supercapacitor Charging

Radio Transmitters and Other Handheld Devices

LTC3619B

400mA/800mA Synchronous

Step-Down DC/DC with

Average Input Current Limit

DescripTion

The LTC

®

3619B is a dual monolithic synchronous buck

regulator using a constant frequency current mode ar-

chitecture.

The input supply voltage range is 2.5V to 5.5V, making it

ideal for Li-Ion and USB powered applications. 100% duty

cycle capability provides low dropout operation, extend-

ing the run time in battery-operated systems. Low output

voltages are supported with the 0.6V feedback reference

voltage. Channel 1 and channel 2 can supply 400mA and

800mA output current, respectively.

The LTC3619B’s programmable average input current limit

is ideal for USB applications and for point-of-load power

supplies because the LTC3619B’s limited input current

will still allow its output to deliver high peak load currents

without collapsing the input supply. When the sum of

both channels’ currents exceeds the input current limit,

channel 2 is current limited while channel 1 remains regu-

lated. The operating frequency is internally set at 2.25MHz

allowing the use of small surface mount inductors. Internal

soft-start reduces in-rush current during start-up. The

LTC3619B is available in small MSOP and 3mm

×

3mm

DFN packages. The LTC3619B is also available in a low

quiescent current, high efficiency Burst Mode

®

version,

LTC3619.

applicaTions

n

L,

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

and Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the

property of their respective owners. Protected by U.S. Patents, including 5481178, 6127815,

6304066, 6498466, 6580258, 6611131.

Typical applicaTion

Dual Monolithic Buck Regulator in 10-Lead 3mm

×

3mm DFN

V

IN

3.4V TO 5.5V

10µF

RUN2 V

IN

RUN1

PGOOD2 PGOOD1

V

OUT2

3.4V AT

800mA

1.5µH

LTC3619B

SW2

1190k

2.2mF

×2

SuperCap

255k

SW1

3.3µH

22pF

V

OUT1

1.8V AT

400mA

V

OUT

200mV/DIV

V

IN

AC-COUPLED

1V/DIV

I

OUT

500mA/DIV

I

IN

500mA/DIV

1ms/DIV

3619B TA01

3619B TA01b

GSM Pulse Load

+

V

FB2

V

FB1

RLIM GND

255k

511k

10µF

1000pF

116k

I

LIM

= 475mA

V

IN

= 5V, 500mA COMPLIANT

I

LOAD

= 0A to 2.2A, CHANNEL 1 UNLOADED

3619bfb

1

LTC3619B

absoluTe MaxiMuM raTings

(Note 1)

Input Supply Voltage (V

IN

) ............................. –0.3 to 6V

V

FB1

, V

FB2

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

IN

+ 0.3V

RUN1, RUN2, RLIM .......................... –0.3V to V

IN

+ 0.3V

SW1, SW2........................................ –0.3V to V

IN

+ 0.3V

PGOOD1, PGOOD2 ........................... –0.3V to V

IN

+ 0.3V

P-channel SW Source Current (DC) (Note 2)

Channel 1 ........................................................ 600mA

Channel 2 ................................................................1A

N-channel SW Source Current (DC) (Note 2)

Channel 1 ........................................................ 600mA

Channel 2 ................................................................1A

Peak SW Source and Sink Current (Note 2)

Channel 1 ........................................................ 900mA

Channel 2 ............................................................. 2.7A

Operating Junction Temperature Range

(Notes 3, 6, 8) ........................................–40 to 125°C

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

Lead Temperature (Soldering, 10 sec)

MSOP Package ................................................. 300°C

Reflow Peak Body Temperature ............................ 260°C

pin conFiguraTion

TOP VIEW

V

FB1

RUN1

RLIM

PGOOD1

SW1

1

2

3

4

5

11

GND

10 V

FB2

9 RUN2

8 PGOOD2

7 SW2

6 V

IN

TOP VIEW

V

FB1

RUN1

RLIM

PGOOD1

SW1

1

2

3

4

5

11

GND

10

9

8

7

6

V

FB2

RUN2

PGOOD2

SW2

V

IN

DD PACKAGE

10-LEAD (3mm

×

3mm) PLASTIC DFN

T

JMAX

= 125°C,

θ

JA

= 40°C/W

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

MSE PACKAGE

10-LEAD PLASTIC MSOP

T

JMAX

= 125°C,

θ

JA

= 45°C/W

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

orDer inForMaTion

LEAD FREE FINISH

LTC3619BEDD#PBF

LTC3619BIDD#PBF

LTC3619BEMSE#PBF

LTC3619BIMSE#PBF

TAPE AND REEL

LTC3619BEDD#TRPBF

LTC3619BIDD#TRPBF

LTC3619BEMSE#TRPBF

LTC3619BIMSE#TRPBF

PART MARKING*

LFFH

LTFFJ

PACKAGE DESCRIPTION

10-Lead (3mm

×

3mm) Plastic DFN

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. *The temperature grade is 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

l

denotes the specifications which apply over the full operating

junction temperature range, otherwise specifications are at T

A

= 25°C (Note 3)

SYMBOL

V

IN

V

UV

PARAMETER

V

IN

Operating Voltage Range

V

IN

Undervoltage Lockout

V

IN

Low to High

CONDITIONS

l

elecTrical characTerisTics

MIN

2.5

TYP

2.1

MAX

5.5

2.5

UNITS

V

3619bfb

2

LTC3619B

elecTrical characTerisTics

SYMBOL

I

FB

V

FBREG

ΔV

LINEREG

ΔV

LOADREG

I

S

f

OSC

I

LIM(PEAK)

I

INLIM

R

DS(ON)

PARAMETER

Feedback Pin Input Current

Feedback Voltage (Channels 1, 2)

V

FB

Line Regulation

V

FB

Load Regulation (Channel 1)

V

FB

Load Regulation (Channel 2)

Supply Current

Active Mode (Note 4)

Shutdown

Oscillator Frequency

Peak Switch Current Limit

Channel 1 (400mA)

Channel 2 (800mA)

Input Average Current Limit

LTC3619BE, –40°C < T

J

< 85°C (Note 7)

LTC3619BI, –40°C < T

J

< 125°C (Note 7)

V

IN

= 2.5V to 5.5V (Note 7)

I

LOAD

= 0mA to 400mA (Note 7)

I

LOAD

= 0mA to 800mA (Note 7)

V

FB1

= V

FB2

= 0.95

×

V

FBREG

V

RUN1

= V

RUN2

= 0V, V

IN

= 5.5V

V

FB

= V

FBREG

V

IN

= 5V, V

FB

< V

FBREG

, Duty Cycle <35%

RLIM = 116k

RLIM = 116k, LTC3619BE

RLIM = 116k, LTC3619BI

V

IN

= 5V, I

SW

= 100mA

V

IN

= 5V, I

SW

= 100mA

V

IN

= 5V, I

SW

= 100mA

V

IN

= 5V, I

SW

= 100mA

V

IN

= 5V, V

RUN

= 0V

V

FB

from 0.06V to 0.54V

l

The

l

denotes the specifications which apply over the full operating

junction temperature range, otherwise specifications are at T

A

= 25°C (Note 3)

CONDITIONS

l

MIN

0.588

0.582

TYP

0.600

0.01

0.5

600

MAX

±30

0.612

0.618

0.25

UNITS

nA

V

%/V

%

875

1

2.7

µA

MHz

mA

1.8

550

1800

2.25

800

2400

475

0.45

0.35

0.27

0.25

0.01

l

450

437

427

500

513

523

mA

Ω

Channel 1 (Note 5)

Top Switch On-Resistance

Bottom Switch On-Resistance

Channel 2 (Note 5)

Top Switch On-Resistance

Bottom Switch On-Resistance

Switch Leakage Current

Soft-Start Time

RUN Threshold High

RUN Leakage Current

Power Good Threshold

I

SW(LKG)

t

SOFTSTART

V

RUN

I

RUN

PGOOD

1

1.3

1.2

1

µA

ms

V

µA

%

0.3

0.4

l

0.95

1

0.01

0V ≤ V

RUN

≤ 5V

Entering Window

V

FB

Ramping Up

V

FB

Ramping Down

Leaving Window

V

FB

Ramping Up

V

FB

Ramping Down

PGOOD Rising and Falling, V

IN

= 5V

–5

5

–7

7

9

–9

90

11

–11

30

±1

%

µs

Ω

µA

PGOOD Blanking

R

PGOOD

I

PGOOD

Power Good Blanking Time

Power Good Pull-Down On-Resistance

PGOOD Leakage Current

8

V

PGOOD

= 5V

15

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:

Guaranteed by long term current density limitations.

Note 3:

The LTC3619B is tested under pulsed load conditions such that

T

J

≈ T

A

. The LTC3619BE is guaranteed to meet performance specifications

from 0°C to 85°C. Specifications over the –40°C to 125°C operating

junction temperature range are assured by design, characterization and

correlation with statistical process controls. The LTC3619BI is guaranteed

to meet specified performance over the full –40°C to 125°C operating

junction temperature range. Note that the maximum ambient temperature

is determined by specific operating conditions in conjunction with board

layout, the rated package thermal resistance and other environmental

factors.

Note 4:

Dynamic supply current is higher due to the internal gate charge

being delivered at the switching frequency.

Note 5:

The switch on-resistance is guaranteed by correlation to wafer

level measurements.

Note 6:

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.

Note 7:

The converter is tested in a proprietary test mode that connects

the output of the error amplifier to the SW pin, which is connected to an

external servo loop.

Note 8:

T

J

is calculated from the ambient temperature T

A

and the power

dissipation as follows: T

J

= T

A

+ (P

D

)(θ

JA

°C/W)

3619bfb

3

LTC3619B

Typical perForMance characTerisTics

Pulse-Skipping Mode Operation

900

SW

2V/DIV

SUPPLY CURRENT (µA)

V

OUT

50mV/DIV

AC-

COUPLED

I

L

100mA/DIV

V

IN

= 5V

V

OUT

= 3.3V

I

LOAD

= 5mA

5µs/DIV

3619B G01

T

A

= 25°C, V

IN

= 5V, unless otherwise noted.

Supply Current vs Temperature

800

700

EFFICIENCY (%)

600

500

400

300

200

–50

–25

0

25

50

75

TEMPERATURE (°C)

100

125

V

IN

= 2.7V

RUN1 = RUN2 = V

IN

I

LOAD

= 0A

V

IN

= 5.5V

100

90

80

70

60

50

40

30

20

10

Efficiency vs Input Voltage

I

OUT

= 100mA

I

OUT

= 400mA

I

OUT

= 800mA

V

OUT

= 3.3V

CHANNEL 2

4

4.5

V

IN

(V)

I

OUT

= 10mA

I

OUT

= 1mA

I

OUT

= 0.1mA

0

3.5

5

5.5

3619B G03

3619B G02

Regulated Voltage vs Temperature

1.5

1.0

V

FB

ERROR (%)

0.5

0

–0.5

–1.0

–1.5

–50

FREQUENCY (MHz)

2.5

2.4

2.3

2.2

2.1

2.0

1.9

–25

0

25

50

75

TEMPERATURE (°C)

100

125

Oscillator Frequency

vs Temperature

1000

Switch Leakage vs Input Voltage

CHANNEL 1

CHANNEL 2

800

LEAKAGE CURRENT (pA)

600

MAIN SWITCH

400

SYNCHRONOUS SWITCH

1.8

–50

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5V

–25

0

25

50

75

TEMPERATURE (°C)

100

125

200

0

2.5

3

3.5

3619B G04

3619B G05

4

V

IN

(V)

4.5

5

5.5

3619B G06

Switch On-Resistance

vs Input Voltage

650

CHANNEL 1

CHANNEL 2

0.7

Switch On-Resistance

vs Temperature, Channel 1

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 5V

PFET R

DS(ON)

(Ω)

MAIN SWITCH

0.5

0.4

0.3

0.2

0.1

0

SYNCHRONOUS SWITCH

–25

0

25

50

75

TEMPERATURE (°C)

100

125

Switch On-Resistance

vs Temperature, Channel 2

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 5V

0.7

MAIN SWITCH

0.6

0.5

0.4

0.3

0.2

SYNCHRONOUS SWITCH

–25

0

25

50

75

TEMPERATURE (°C)

100

0.1

125

NFET R

DS(ON)

(Ω)

0.6

R

DS(ON)

(mΩ)

550

MAIN SWITCH

450

R

DS(ON)

(Ω)

0.5

0.4

350

SYNCHRONOUS SWITCH

250

2.5

3

3.5

4

V

IN

(V)

0.3

4.5

5

5.5

3619B G07

0.2

–50

–0.1

–50

3619B G08

3619B G09

3619bfb

4

LTC3619B

Typical perForMance characTerisTics

Efficiency vs Load Current

100

V

OUT

= 3.3V

90 CHANNEL 1

80

EFFICIENCY (%)

70

60

50

40

30

20

10

0

0.0001

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5V

0.001

0.01

0.1

OUTPUT CURRENT (A)

1

3619B G10

T

A

= 25°C, V

IN

= 5V, unless otherwise noted.

Efficiency vs Load Current

100

V

OUT

= 3.3V

90 CHANNEL 2

80

EFFICIENCY (%)

70

60

50

40

30

20

10

0

0.0001

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5V

0.001

0.01

0.1

OUTPUT CURRENT (A)

1

3619B G11

Efficiency vs Load Current

100

V

OUT

= 1.2V

90 CHANNEL 1

80

70

60

50

40

30

20

10

0

0.0001

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5V

0.001

0.01

0.1

OUTPUT CURRENT (A)

1

3619B G12

Efficiency vs Load Current

100

V

OUT

= 1.2V

90 CHANNEL 2

80

V

OUT

ERROR (%)

EFFICIENCY (%)

70

60

50

40

30

20

10

0

0.0001

V

IN

= 2.7V

V

IN

= 3.6V

V

IN

= 4.2V

V

IN

= 5V

0.001

0.01

0.1

OUTPUT CURRENT (A)

1

3619B G13

Load Regulation

3.0

2.5

2.0

1.5

1.0

0.5

0

–0.5

–1.0

0

V

OUT

= 1.8V

V

OUT

= 2.5V

V

OUT

= 3.3V

100

200

300

LOAD CURRENT (mA)

400

3619B G14

Load Regulation

3.0

2.5

2.0

V

OUT

ERROR (%)

1.5

1.0

0.5

0

–0.5

–1.0

0

V

OUT

= 1.8V

V

OUT

= 2.5V

V

OUT

= 3.3V

100 200 300 400 500 600 700 800

LOAD CURRENT (mA)

3619B G15

CHANNEL 1

CHANNEL 2

Line Regulation

0.6

0.4

V

OUT

ERROR (%)

0.2

0

–0.2

–0.4

–0.6

2.5

V

OUT

1V/DIV

I

L

250mA/DIV

V

OUT

= 1.8V

I

LOAD

= 100mA

RUN

2V/DIV

Start-Up from Shutdown

RUN

2V/DIV

V

OUT

2V/DIV

R

LIM

1V/DIV

I

IN

500mA/DIV

200µs/DIV

V

IN

= 5V, V

OUT

= 3.3V

R

LOAD

= 7Ω

C

LOAD

= 4.7µF

3619B G17

Start-Up from Shutdown

CHANNEL 2

2ms/DIV

V

IN

= 5V, V

OUT

= 3.4V

R

L

= NO LOAD, C

L

= 4.4mF

,

C

LIM

= 2200pF I

LIM

= 500mA

3619B G18

3.0

3.5

4.0

V

IN

(V)

4.5

5.0

5.5

3619B G16

3619bfb

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
Type	Synchronous Step Down
Output Type	Adjustable
Switching Frequency (kHz)	2700
Switching Regulator	Yes
Number of Outputs	2
Output Voltage (V)	0.6 to 5
Maximum Output Current (A)	0.4\|0.8
Minimum Input Voltage (V)	2.5
Maximum Input Voltage (V)	5.5
Operating Supply Voltage (V)	2.5 to 5.5
Line Regulation	0.25%/V
Load Regulation	0.5%(Typ)
Efficiency (%)	96
Minimum Operating Temperature (°C)	-40
Maximum Operating Temperature (°C)	125
Supplier Temperature Grade	Industrial
Packaging	Tape and Reel
Pin Count	10
Standard Package Name	DFN
Supplier Package	DFN EP
Mounting	Surface Mount
Package Height	0.75(Max)
Package Length	3
Package Width	3
PCB changed	10
Lead Shape	No Lead

LTC3619BIDD#TRPBF

LTC3619BIDD#TRPBF Overview

LTC3619BIDD#TRPBF Parametric

Preview

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