LT1946

1

1946fb

3.3V

SW

FB

LT1946

4.7

µH

D1

100nF

470pF

49.9k

8V

430mA

1946 F01

20

µF

2.2

µF

GND

COMP

SS

SHDN

OFF ON

C1: 2.2

µF, X5R OR X7R, 6.3V

C2: 2

× 10µF, X5R OR X7R, 10V

D1: MICROSEMI UPS120 OR EQUIVALENT

L1: TDK RLF5018T-4R7M1R4

28.7k

5.23k

■

GPS Receivers

■

1.5A, 36V Internal Switch

■

Output Voltage Up to 34V

■

Small 8-Lead MSOP Package

1.2MHz Boost

DC/DC Converter with

1.5A Switch and Soft-Start

Figure 1. 3.3V to 8V, 430mA Step-Up DC/DC Converter

The LT

containing an internal 1.5A, 36V switch. Capable of gener-

ating 8V at 430mA from a 3.3V input, the LT1946 is ideal

for large TFT-LCD panel power supplies. The LT1946

switches at 1.2MHz, allowing the use of tiny, low profile

inductors and low value ceramic capacitors. Loop com-

pensation can be either internal or external, giving the user

flexibility in setting loop compensation and allowing opti-

mized transient response with low ESR ceramic output

capacitors. Soft-start is controlled with an external capaci-

tor, which determines the input current ramp rate during

start-up.

The 8-lead MSOP package and high switching frequency

ensure a low profile overall solution less than 1.2mm high.

LOAD CURRENT (mA)

0

65

70

75

300

500

1946 F01b

60

55

50

100

200

400

80

85

90

Efficiency

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

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

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