16

LT1533

Low Noise 5V to –12V Forward Push-Pull Converter. Output Noise Is Below 100

µV.

Noise Performance Is Identical to Positive Output Version. See AN70 for Details

SHDN

DUTY

SYNC

COL A

COL B

PGND

NFB

FB

LT1533

GND

5V

14

2

15

16

13

12

8

11

3

4

5

6

10

3300pF

18k

0.01

µF

15k

L1

4.7

µF

15k

+

T1

1N4148

1N4148

L2

100

µH

L3

100

µH

2.4k

1%

7

9

9.6k

1%

47

µF

47

µF

L1: 22nH INDUCTOR. COILCRAFT B-07T TYPICAL,

TRACE INDUCTANE OR BEAD

L2, L3: COILTRONICS CTX100-3

T1: COILTRONICS CTX02-13665-X1

–12V

1533 TA03

OPTIONAL FOR

LOWEST RIPPLE

()

SHDN

DUTY

SYNC

COL A

COL B

PGND

FB

NFB

LT1533

GND

2.7V TO 4V

(3 NiCd BATTERIES)

14

2

15

16

13

12

7

11

3

4

5

6

10

3300pF

18k

0.01

µF

15k

L2

4.7

µF

15k

+

T1

L1

100

µH

L3

100

µH

3.48k

1%

8

9

21.5k

1%

47

µF

+

47

µF

9V

1N4148

1N4148

L1, L3: COILTRONICS CTX100-3

L2: 22nH TRACE INDUCTANCE, FERRITE BEAD OR

INDUCTOR COILCRAFT B-07T TYPICAL

T1: CTX02-13665-X1

1533 TA04

+

OPTIONAL FOR

LOWEST RIPPLE

()

Electronic Equivalent of 9V Battery Operates from Three NiCd Cells.

Output Noise Is Below 100

µV. See AN70 for Details