11

LT1572

S

APPLICATI

TYPICAL

Negative Buck Converter

Backlight CCFL Supply (see AN55 for details)

GND

2

µF

1572 TA04

D1

1N914

33pF

3kV

10

µF

TANT

R3

10k

50k

INTENSITY

ADJUST

L1**

300

µH

4.5V TO 20V

Q1,Q2 = BCP56 OR MPS650/561

COILTRONICS CTX300-4

SUMIDA 6345-020 OR COILTRONICS 110092-1

A MODIFICATION WILL ALLOW OPERATION DOWN TO 4.5V. CONSULT FACTORY.

*

**

***

†

C6

1 F

µ

R1

560

Ω

1k

LT1572

CATHODE

ANODE

E2

E1

D2

1N914

LAMP

FB

L2***

0.02

µF

A

B

Q1*

+

+

Q2*

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-

tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

C3*

100

µF

–5.2V

0.75A

1572 TA03

R3

L1**

50

µH

R1

4.64k

C2

200

µF

C1

Q1

2N3906

CATHODE

FB

ANODE

E2

E1

LT1572

GND

–7V TO –20V

REQUIRED IF INPUT LEADS

≥ 2"

PULSE ENGINEERING 92114

COILTRONICS 50-2-52

*

**

R2

1.24k

R4

12k

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