LTC1871

32

1871fe

TYPICAL APPLICATIONS

18V to 27V Input, 28V Output, 400W 2-Phase, Low Ripple, Synchronized RF Base Station Power Supply (Boost)

5V to 12V Input, ±12V/0.2A Output SEPIC Converter with Undervoltage Lockout

RUN

FB

FREQ

MODE/SYNC

SENSE

GATE

GND

1

2

3

4

5

10

9

8

7

6

LTC1871

150k

5%

0.007Ω

1W

EXT CLOCK

INPUT (200kHz)

R2

8.45k

1%

4.7μF

X5R

2.2μF

35V

X5R

M1

D1

L2

5.6μH

L5*

0.3μH

47pF

47pF

18V to 27V

GND

28V

14A

1871 TA04

2.2μF

35V

X5R

×3

330μF

50V

SANYO 50MV330AX

TAIYO YUDEN GMK325BJ225MN

TAIYO YUDEN LMK316BJ475ML

L1 TO L4: SUMIDA CEP125-5R6MC-HD

L5:

SUMIDA CEP125-0R3NC-ND

D1, D2:

ON SEMICONDUCTOR MBR2045CT

M1, M2:

INTERNATIONAL RECTIFIER IRLZ44NS

R1

93.1k

1%

L1

5.6μH

OPTIONAL SECONDARY

FILTER TO REDUCE

OUTPUT RIPPLE FROM

+

330μF

50V

×4

2.2μF

35V

X5R

330μF

50V

RUN

FB

FREQ

MODE/SYNC

SENSE

GATE

GND

1

2

3

4

5

10

9

8

7

6

LTC1871

150k

5%

R3

12.1k

1%

22k

R4

261k

1%

4.7μF

X5R

2.2μF

35V

X5R

M2

D2

L4

5.6μH

47pF

6.8nF

47pF

2.2μF

35V

X5R

×3

330μF

50V

L3

5.6μH

+

0.007Ω

1W

+

RUN

FB

FREQ

MODE/SYNC

SENSE

GATE

GND

1

2

3

4

5

10

9

8

7

6

LTC1871

60.4k

1%

0.02Ω

R4

127Ω

1%

R2

54.9k

1%

R3

1.10k

1%

4.7μF

10V

X5R

1μF

16V

X5R

M1

D1

L1*

•

22k

6.8nF

100pF

4.7μF

16V

X5R

5V to 12V

12V

0.4A

GND

–12V

0.4A

1871 TA03

4.7μF

16V

X5R

×3

4.7μF

16V

X5R

×3

D1, D2:

MBS120T3

L1 TO L3: COILTRONICS VP1-0076 (*COUPLED INDUCTORS)

M1:

SILICONIX/VISHAY Si4840

R1

127k

1%

47μF

16V

AVX

4.7μF

16V

X5R

+

L2*

L3*

D2

•

•

NOTE: