LTC1142HVCG-ADJ#TRPBF Datasheet LTC1142HVCG-ADJ#PBF, LTC1142LCG-ADJ#PBF, LTC1142CG#PBF | P1-P3

1

LTC1142/LTC1142L/LTC1142HV

Dual High Efficiency

Synchronous Step-Down

Switching Regulators

, LTC and LT are registered trademarks of Linear Technology Corporation.

The LTC

®

1142/LTC1142L/LTC1142HV are dual synchro-

nous step-down switching regulator controllers featuring

automatic Burst Mode

TM

operation to maintain high efficien-

cies at low output currents. The devices are composed of two

separate regulator blocks, each driving a pair of external

complementary power MOSFETs, at switching frequencies

up to 250kHz, using a constant off-time current mode archi-

tecture providing constant ripple current in the inductor.

The operating current level for both regulators is user pro-

grammable via an external current sense resistor. Wide input

supply range allows operation from 3.5V* to 18V (20V

maximum). Constant off-time architecture provides low drop-

out regulation limited only by the R

DS(ON)

of the external

MOSFET and resistance of the inductor and current sense

resistor.

The LTC1142 series is ideal for applications requiring dual

output voltages with high conversion efficiencies over a wide

load current range in a small amount of board space.

■

Dual Outputs: 3.3V and 5V or User Programmable

■

Ultrahigh Efficiency: Over 95% Possible

■

Current Mode Operation for Excellent Line and Load

Transient Response

■

High Efficiency Maintained over 3 Decades of

Output Current

■

Low Standby Current at Light Loads: 160µA/Output

■

Independent Micropower Shutdown: I

Q

< 40µA

■

Wide V

IN

Range: 3.5V to 20V

■

Very Low Dropout Operation: 100% Duty Cycle

■

Synchronous FET Switching for High Efficiency

■

Available in Standard 28-Pin SSOP

■

Notebook and Palmtop Computers

■

Battery-Operated Digital Devices

■

Portable Instruments

■

DC Power Distribution Systems

Figure 1. High Efficiency Dual 3.3V, 5V Supply

1000pF

+

1000pF

PDRIVE 3

SENSE

+

3

SENSE

–

3

NDRIVE 3

PGND3 SGND3 C

T3

I

TH3

I

TH5

C

T5

SGND5

PGND5

NDRIVE 5

SENSE

–

5

SENSE

+

5

PDRIVE 5

V

IN3

SHDN3

SHDN5

V

IN5

LTC1142HV

C

T5

390pF

4 3 25 27 13 11 17 18

R

C5

1k

C

C3

3300pF

C

C5

3300pF

C

T3

560pF

R

C3

1k

0.22µF

2

24 16 10

9

15

14

20

23

1

28

6

V

OUT5

5V/2A

C

OUT5

220µF

10V

× 2

R

SENSE5

0.05Ω

P-CH

Si9430DY

L2

50µH

D2

MBRS130L

N-CH

Si9410DY

0V = NORMAL

>1.5V = SHDN

0.22µF

C

IN5

22µF

25V

× 2

C

IN3

22µF

25V

× 2

P-CH

Si9430DY

N-CH

Si9410DY

D1

MBRS130L

C

OUT3

220µF

10V

× 2

L1

50µH

R

SENSE3

0.05Ω

V

OUT3

3.3V/2A

V

IN

5.2V TO 18V

R

SENSE3,

R

SENSE5

: DALE WSL-2010-.05

L1, L2: COILTRONICS CTX50-2-MP

PINS 5, 7, 8, 19, 21, 22: NC

1142 F01

NOTE: COMPONENTS OPTIMIZED FOR HIGHEST EFFICIENCY, NOT MINIMUM BOARD SPACE.

+

APPLICATIO S

U

FEATURES

TYPICAL APPLICATIO

U

DESCRIPTIO

U

Burst Mode is a trademark of Linear Technology Corporation.

2

LTC1142/LTC1142L/LTC1142HV

Input Supply Voltage (Pins 10, 24)

LTC1142, LTC1142L-ADJ ..................... 16V to –0.3V

LTC1142HV, LTC1142HV-ADJ ............. 20V to –0.3V

Continuous Output Current (Pins 6, 9, 20, 23) .... 50mA

Sense Voltages (Pins 1, 14, 15, 28)

V

IN

> 13V.............................................. 13V to –0.3V

V

IN

< 13V.................................. (V

IN

+ 0.3V) to –0.3V

Operating Ambient Temperature Range ...... 0°C to 70°C

Extended Commercial

Temperature Range ........................... – 40°C to 85°C

Junction Temperature (Note 2)............................ 125°C

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

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

ABSOLUTE AXI U RATI GS

W

WW

U

PACKAGE/ORDER I FOR ATIO

UUW

ELECTRICAL CHARACTERISTICS

ORDER PART

NUMBER

Consult factory for Industrial and Military grade parts.

ORDER PART

NUMBER

LTC1142CG

LTC1142HVCG

LTC1142HVCG-ADJ

LTC1142LCG-ADJ

T

JMAX

= 125°C, θ

JA

= 95°C/W T

JMAX

= 125°C, θ

JA

= 95°C/W

1

2

3

4

5

6

7

8

9

10

11

12

13

14

TOP VIEW

G PACKAGE

28-LEAD PLASTIC SSOP

28

27

26

25

24

23

22

21

20

19

18

17

16

15

SENSE

+

3

SHDN3

SGND3

PGND3

NC

NDRIVE 3

NC

PDRIVE 5

V

IN5

C

T5

INTV

CC5

I

TH5

SENSE

–

5

SENSE

–

3

I

TH3

INTV

CC3

C

T3

V

IN3

PDRIVE 3

NC

NDRIVE 5

NC

PGND5

SGND5

SHDN5

SENSE

+

5

1

2

3

4

5

6

7

8

9

10

11

12

13

14

TOP VIEW

G PACKAGE

28-LEAD PLASTIC SSOP

28

27

26

25

24

23

22

21

20

19

18

17

16

15

SENSE

+

1

V

FB1

SHDN1

SGND1

PGND1

NDRIVE 1

NC

PDRIVE 2

V

IN2

C

T2

INTV

CC2

I

TH2

SENSE

–

2

SENSE

–

1

I

TH1

INTV

CC1

C

T1

V

IN1

PDRIVE 1

NC

NDRIVE 2

PGND2

SGND2

SHDN2

V

FB2

SENSE

+

2

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

2

, V

16

Feedback Voltage LTC1142HV-ADJ, LTC1142L-ADJ : V

10

, V

24

= 9V ● 1.21 1.25 1.29 V

I

2

, I

16

Feedback Current LTC1142HV-ADJ, LTC1142L-ADJ ● 0.2 1 µA

V

OUT

Regulated Output Voltage LTC1142, LTC1142HV

3.3V Output I

LOAD

= 700mA, V

24

= 9V ● 3.23 3.33 3.43 V

5V Output I

LOAD

= 700mA, V

10

= 9V ● 4.90 5.05 5.20 V

∆V

OUT

Output Voltage Line Regulation V

10,

V

24

= 7V to 12V, I

LOAD

= 50mA – 40 0 40 mV

Output Voltage Load Regulation Figure 1 Circuit

3.3V Output 5mA < I

LOAD

< 2A ● 40 65 mV

5V Output 5mA < I

LOAD

< 2A ● 60 100 mV

Output Ripple (Burst Mode) I

LOAD

= 0A 50 mV

P-P

I

10

, I

24

Input DC Supply Current (Note 3) LTC1142

Normal Mode 4V < V

10

, V

24

< 12V 1.6 2.1 mA

Sleep Mode 4V < V

24

< 12V, 6V < V

10

< 12V 160 230 µA

Shutdown V

SD1

= V

SD2

= 2.1V, 4V < V

10

, V

24

< 12V 10 20 µA

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

A

= 25°C. V

10

= V

24

= 10V, V

SHDN

= 0V unless otherwise noted.

(Note 1)

3

LTC1142/LTC1142L/LTC1142HV

ELECTRICAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

A

= 25°C. V

10

= V

24

= 10V, V

SHDN

= 0V unless otherwise noted.

V

2

, V

16

Feedback Voltage LTC1142HV-ADJ Only: V

10

, V

24

= 9V 1.21 1.25 1.29 V

I

2

, I

16

Feedback Current LTC1142HV-ADJ Only 0.2 1 µA

V

OUT

Regulated Output Voltage LTC1142, LTC1142HV

3.3V Output I

LOAD

= 700mA, V

24

= 9V 3.17 3.33 3.43 V

5V Output I

LOAD

= 700mA, V

10

= 9V 4.85 5.05 5.20 V

I

10

, I

24

Input DC Supply Current (Note 3) LTC1142

Normal Mode 4V < V

10

, V

24

< 12V 1.6 2.4 mA

Sleep Mode 4V < V

24

< 12V, 6V < V

10

< 12V 160 260 µA

Shutdown V

SHDN

= 2.1V, 4V < V

10

, V

24

< 12V 10 22 µA

Input DC Supply Current (Note 3) LTC1142HV-ADJ, LTC1142HV

Normal Mode 4V < V

10

, V

24

< 18V 1.6 2.6 mA

Sleep Mode 4V < V

24

< 18V, 6V < V

10

< 18V 160 280 µA

Shutdown V

SHDN

= 2.1V, 4V < V

10

, V

24

< 12V 10 24 µA

Input DC Supply Current (Note 3) LTC1142L-ADJ (Note 6)

Normal Mode 3.5V < V

10

, V

24

< 12V 1.6 2.4 mA

Sleep Mode 3.5V < V

10

, V

24

< 12V 160 260 µA

Shutdown V

SD1

= V

SD2

= 2.1V, 3.5V < V

10

, V

24

< 12V 10 22 µA

V

1

– V

28

Current Sense Threshold Voltage LTC1142HV-ADJ, LTC1142L-ADJ

V

15

– V

14

V

14

= V

28

= V

OUT

+ 100mV, V

2

= V

16

= V

REF

+ 25mV 25 mV

V

14

= V

28

= V

OUT

– 100mV, V

2

= V

16

= V

REF

– 25mV 125 150 175 mV

LTC1142, LTC1142HV

V

28

= V

OUT

+ 100mV (Forced) 25 mV

V

28

= V

OUT

– 100mV (Forced) 125 150 175 mV

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

Input DC Supply Current (Note 3) LTC1142HV, LTC1142HV-ADJ

Normal Mode 4V < V

10

, V

24

< 18V 1.6 2.3 mA

Sleep Mode 4V < V

24

< 18V, 6V < V

10

< 18V 160 250 µA

Shutdown V

SD1

= V

SD2

= 2.1V, 4V < V

10

, V

24

< 18V 10 22 µA

Input DC Supply Current (Note 3) LTC1142L-ADJ (Note 6)

Normal Mode 3.5V < V

10

, V

24

< 12V 1.6 2.1 mA

Sleep Mode 3.5V < V

10

, V

24

< 12V 160 230 µA

Shutdown V

SD1

= V

SD2

= 2.1V, 3.5V < V

10

, V

24

< 12V 10 20 µA

V

1

– V

28

Current Sense Threshold Voltage LTC1142HV-ADJ, LTC1142L-ADJ

V

15

– V

14

V

14

= V

28

= V

OUT

+ 100mV, V

2

= V

16

= V

REF

+ 25mV 25 mV

V

14

= V

28

= V

OUT

– 100mV, V

2

= V

16

= V

REF

– 25mV ● 130 150 170 mV

LTC1142, LTC1142HV

V

28

= V

OUT

+ 100mV (Forced) 25 mV

V

28

= V

OUT

– 100mV (Forced) ● 130 150 170 mV

LTC1142, LTC1142HV

V

14

= V

OUT

+ 100mV (Forced) 25 mV

V

14

= V

OUT

– 100mV (Forced) ● 130 150 170 mV

V

SHDN

Shutdown Pin Threshold 0.5 0.8 2 V

I

SHDN

Shutdown Pin Input Current 0V < V

SHDN

< 8V, V

10

, V

24

= 16V 1.2 5 µA

I

11

, I

24

C

T

Pin Discharge Current V

OUT

in Regulation, V

SENSE

–

= V

OUT

50 70 90 µA

V

OUT

= 0V 2 10 µA

t

OFF

Off-Time (Note 4) C

T

= 390pF, I

LOAD

= 700mA 4 5 6 µs

t

r

, t

f

Driver Output Transition Times C

L

= 3000pF (Pins 6, 9, 20, 23), V

10

, V

24

= 6V 100 200 ns

–40°C ≤ T

A

≤ 85°C (Note 5), V

10

= V

24

= 10V, unless otherwise noted.

LTC1142HVCG-ADJ#TRPBF

LTC1142HVCG-ADJ#TRPBF

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