LTC3829IUHF#TRPBF Datasheet LTC3829EFE#TRPBF, LTC3829IFE#TRPBF, LTC3829EUHF#TRPBF | P1-P3

LTC3829

1

3829fc

For more information www.linear.com/LTC3829

3-Phase, Single Output

Synchronous Step-Down

DC/DC Contr

oller with Diffamp

TYPICAL APPLICATION

DESCRIPTION

The LT C

®

3829 is a high performance 3-phase single output

synchronous step-down DC/DC switching controller that

drives all N-channel synchronous power MOSFET stages.

A constant frequency current mode architecture allows a

phase-lockable frequency of up to 770kHz. Power loss and

noise due to ESR of the input capacitors are minimized by

operating the three controller output stages out of phase.

The LTC3829 can be configured for 6-phase operation,

has DCR temperature compensation, and output foldback

current limiting. This device features a precision 0.6V

reference and a power good indicator.

Light load efficiency is optimized by using a choice of

output Stage Shedding or Burst Mode operation. A dif

-

ferential amplifier

provides true remote sensing of the

output voltage at the point of load.

The LTC3829 is available in both low profile 38-pin 5mm

× 7mm QFN and Exposed Pad FE packages.

FEATURES

APPLICATIONS

n

Optional Nonlinear Control for Fast Response

n

±0.75%, 0.6V Reference Accuracy

n

PWM, Stage Shedding™ or Burst Mode

®

Operation

n

High Efﬁciency: Up to 95%

n

R

SENSE

or DCR Current Sensing

n

Programmable DCR Temperature Compensation

n

Phase-Lockable Fixed Frequency: 250kHz to 770kHz

n

True Remote Sense Differential Ampliﬁer

n

Programmable Active Voltage Positioning (AVP)

n

Triple N-Channel MOSFET Synchronous Drive

n

Wide V

IN

Range: 4.5V to 38V Operation

n

V

OUT

Range: 0.6V to 5V without Diffamp

n

V

OUT

Range: 0.6V to 3.3V with Diffamp

n

Clock Input and Output for 6-Phase Operation

n

Adjustable Soft-Start or V

OUT

Tracking

n

38-Pin (5mm × 7mm) QFN and FE Packages

n

Notebook and Palmtop Computers

n

Telecom Systems

n

Portable Instruments

n

DC Power Distribution Systems

+

INTV

CC

BOOST1

BOOST2

BOOST3

FREQ

I

TH

TK/SS

SENSE1

+

SENSE1

–

PGND

BG1

SW1

TG1

4.7µF

SW3 SW2 SW1

0.1µF

680pF

100k

5k

20k

22µF

35V

×3

V

IN

6V TO 28V

C

OUT

470µF

4V

×4

V

OUT

1.2V

50A

SENSE2

+

SENSE2

–

BG2

SW2

TG2

SENSE3

+

SENSE3

–

BG3

SW3

TG3

SGND

DIFFOUT

V

FB

DIFFN

DIFFP

0.6µH

V

IN

V

IN

0.002Ω

0.6µH

0.002Ω

0.6µH

3829 TA01

0.002Ω

V

IN

LTC3829

L, LT , LT C , LT M , Burst Mode, OPTI-LOOP, PolyPhase, Linear Technology, the Linear logo are

registered trademarks and Stage Shedding, No R

SENSE

are trademarks of Linear Technology

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

U.S. Patents, including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, 6498466,

6674274, 6611136.

LOAD CURRENT (A)

0.1

70

EFFICIENCY (%)

POWER LOSS (W)

75

80

85

90

1 10 100

3829 TA01b

65

60

55

50

95

100

4

6

8

10

12

2

0

14

16

V

IN

= 12V

V

OUT

= 1.5V

EFFICIENCY

POWER LOSS

Efficiency

LTC3829

2

3829fc

For more information www.linear.com/LTC3829

Input Supply Voltage (V

IN

) ......................... 40V to –0.3V

Topside Driver Voltages (BOOSTn) ............. 46V to –0.3V

Switch Voltage (SWn) ................................... 40V to –5V

Boosted Driver Voltage (BOOSTn – SWn) .... 6V to –0.3V

INTV

CC

, PGOOD, RUN, EXTV

CC

................... 6V to –0.3V

ITEMP, IFAST, V

FB

Pin Voltages ............INTV

CC

to –0.3V

TK/SS, FREQ, DIFFP, DIFFN, DIFFOUT, ISET

AVP, I

LIM

, MODE, PLLIN Voltages .........INTV

CC

to –0.3V

(Note 1)

ABSOLUTE MAXIMUM RATINGS

13 14 15 16

TOP VIEW

39

UHF PACKAGE

38-LEAD (5mm × 7mm) PLASTIC QFN

17 18 19

38 37 36 35 34 33 32

24

25

26

27

28

29

30

31

8

7

6

5

4

3

2

1DIFFN

DIFFP

RUN

AVP

SENSE1

+

SENSE1

–

SENSE2

+

SENSE2

–

TK/SS

FREQ

SENSE3

+

SENSE3

–

SW1

BG1

BG2

SW2

TG2

BOOST2

V

IN

INTV

CC

EXTV

CC

BG3

SW3

TG3

DIFFOUT

ITEMP

IFAST

MODE

CLKOUT

BOOST1

TG1

V

FB

I

TH

ISET

I

LIM

PGOOD

PLLIN

BOOST3

23

22

21

20

9

10

11

12

T

JMAX

= 125°C, θ

JA

= 34°C/W

EXPOSED PAD (PIN 39) IS SGND/PGND, MUST BE SOLDERED TO PCB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

TOP VIEW

FE PACKAGE

38-LEAD PLASTIC TSSOP

38

37

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

ITEMP

DIFFOUT

DIFFN

DIFFP

RUN

AVP

SENSE1

+

SENSE1

–

SENSE2

+

SENSE2

–

TK/SS

FREQ

SENSE3

+

SENSE3

–

V

FB

I

TH

ISET

I

LIM

PGOOD

IFAST

MODE

CLKOUT

BOOST1

TG1

SW1

BG1

BG2

SW2

TG2

BOOST2

V

IN

INTV

CC

EXTV

CC

BG3

SW3

TG3

BOOST3

PLLIN

39

T

JMAX

= 125°C, θ

JA

= 25°C/W

EXPOSED PAD (PIN 39) IS SGND/PGND, MUST BE SOLDERED TO PCB

PIN CONFIGURATION

I

TH

Voltage ............................................ INTV

CC

to –0.3V

SENSE

+

n, SENSE

–

n................................... 5.7V to –0.3V

Operating Junction Temperature Range

(Notes 2, 3) ............................................ –45°C to 125°C

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

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

LTC3829

3

3829fc

For more information www.linear.com/LTC3829

ORDER INFORMATION

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LTC3829EUHF#PBF LTC3829EUHF#TRPBF 3829 38-Lead (5mm × 7mm) Plastic QFN –40°C to 125°C

LTC3829IUHF#PBF LTC3829IUHF#TRPBF 3829 38-Lead (5mm × 7mm) Plastic QFN –40°C to 125°C

LTC3829EFE#PBF LTC3829EFE#TRPBF LTC3829 38-Lead Plastic TSSOP –40°C to 125°C

LTC3829IFE#PBF LTC3829IFE#TRPBF LTC3829 38-Lead Plastic TSSOP –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 LT C 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/

ELECTRICAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

IN

Input Voltage Range 4.5 38 V

V

OUT

Output Voltage Range 0.6 5.0 V

V

FB

Regulated Feedback Voltage I

TH

Voltage = 1.2V (Note 4) –40°C to 85°C

I

TH

Voltage = 1.2V (Note 4) T

J

= 125°C

l

0.5955

0.593

0.600

0.6045

0.607

V

I

FB

Feedback Current (Note 4) –15 –50 nA

V

REFLNREG

Reference Voltage Line Regulation V

IN

= 4.5V to 38V (Note 4) 0.002 0.02 %/V

V

LOADREG

Output Voltage Load Regulation (Note 4)

Measured in Servo Loop,

∆I

TH

Voltage = 1.2V to 0.7V

Measured in Servo Loop,

∆I

TH

Voltage = 1.2V to 1.6V

l

0.01

–0.01

0.1

–0.1

%

g

m

Transconductance Amplifier g

m

I

TH

= 1.2V, Sink/Source 5µA (Note 4) 2.2 mmho

I

Q

Input DC Supply Current

Normal Mode

Shutdown

(Note 5)

V

IN

= 15V

V

RUN

= 0V

4

40

60

mA

µA

DF

MAX

Maximum Duty Factor In Dropout, f

OSC

= 500kHz 93 94 %

UVLO Undervoltage Lockout V

INTVCC

Ramping Down

l

3.0 3.3 3.6 V

UVLO Hyst UVLO Hysteresis 0.6 V

V

OVL

Feedback Overvoltage Lockout Measured at V

FB

l

0.64 0.66 0.68 V

I

SENSE1,2,3

+

SENSE

+

Pins Bias Current Each Channel, V

SENSE1,2,3

= 3.3V,

V

DIFFP

= 3.3V

l

±1 ±2 µA

I

TEMP

DCR Tempco Compensation Current V

ITEMP

= 0.2V

l

9 10 11 µA

I

TK/SS

Soft-Start Charge Current V

TK/SS

= 0V

l

1.0 1.25 1.5 µA

V

RUN

RUN Pin On Threshold V

RUN

Rising

l

1.1 1.22 1.35 V

RUN Pin On Hysteresis 100 mV

V

SENSE(MAX)

Maximum Current Sense Threshold

(E-Grade)

V

FB

= 0.5V, V

SENSE1,2,3

= 3.3V

I

LIM

= 0V

I

LIM

= Float

I

LIM

= INTV

CC

l

25

45

68

30

50

75

35

55

82

mV

Maximum Current Sense Threshold

(I-Grade)

V

FB

= 0.5V, V

SENSE1,2,3

= 3.3V

I

LIM

= 0V

I

LIM

= Float

I

LIM

= INTV

CC

l

23

43

66

30

50

75

37

57

84

mV

The l denotes the specifications which apply over the full operating

junction temperature range, otherwise specifications are at T

A

= 25°C. V

IN

= 15V, V

RUN

= 5V, unless otherwise noted. (Note 2)

(Note 2)

LTC3829IUHF#TRPBF

LTC3829IUHF#TRPBF

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