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Step-up dc-dc controller – Rainbow Electronics MAX1771 User Manual

Page 15

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MAX1771

12V or Adjustable, High-Efficiency,

Low I

Q

, Step-Up DC-DC Controller

______________________________________________________________________________________

15

MAX1771

SHDN

R1
0.15

R7

200

REF

AGND

GND

4

5

Q1
MTD6N10

6

-48V

EXT

CS

1

L1

D03340

220

µH–680µH

8

3

1

2

D1

MBRS1100T3

D2
CMPZ5240/
MMBZ5240BL

D3

CMPSH-3

C8
1

µF

+5V

300mA

7

C5

0.1

µF

C6

10

µF

100V

FB

3

V+

Q3

MMBT8599LT1

2

C7
220pF

R2
47k

1%

R3
16k

1%

C4

2.2

µF

20V

R5
1k

R6
200k

R4
100k

C1
220

µF

10V

C3
0.33

µF

Q2

MMBT8099LT1

R9

5.1k

C2
220

µF

10V

GND

REF

MAX1771

V+

EXTL

CS

4

SHDN

0.1

µF

3.3V OR 5V

LOGIC

SUPPLY

BATTERY
INPUT
2V TO 12V

8

6, 7

5

RSENSE

0.2

1N5817

1

2

L1

22

µH

OUTPUT

ADJ = 12V TO 24V

(AS SHOWN)

N

47

µF

0.1

µF

FB 3

R3

10k

10k

R2
150k

MMFT3055ELT1

OFF

ON

Figure 7. -48V Input to 5V Output at 300mA, Without a Transformer

Figure 8. 2V Input to 24V Output LCD Bias