1

LT1935

1935f

DESCRIPTIO

FEATURES

APPLICATIO S

TYPICAL APPLICATIO

1.2MHz Boost DC/DC

Converter in ThinSOT

with 2A Switch

The LT

switching regulator. Its unprecedented 2A, 40V internal

switch allows high output currents to be generated in a

small footprint. Intended for space-conscious applica-

tions, the LT1935 switches at 1.2MHz, allowing the use of

tiny, low profile inductors and capacitors 2mm or less in

at 2A independent of supply voltage, resulting in high

efficiency even at maximum power levels from a 3V input.

A constant frequency, internally compensated, current

mode PWM architecture results in low, predictable output

noise that is easy to filter. Low ESR ceramic capacitors can

be used on the output, further reducing noise to the

millivolt level. The high voltage switch on the LT1935 is

rated at 40V, making the device ideal for boost converters

up to 38V as well as for single-ended primary inductance

converter (SEPIC) and flyback designs. The device can

generate 5V at up to 1A from a 3.3V supply or 5V at 550mA

from four alkaline cells in a SEPIC design.

The LT1935 is available in a 5-lead SOT-23 package.

Figure 1. 5V to 12V, 600mA Step-Up DC/DC Converter

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

GND

SW

SHDN

FB

5V

D1

L1

4.2µH

84.5k

LT1935

1935 F01

10µF

4.7µF

10k

12V

600mA

D1: ON SEMI MBRM120

L1: SUMIDA CDRH5D28-4R2

ON OFF

ThinSOT is a trademark of Linear Technology Corporation.

LOAD CURRENT (mA)

0

600

1935 F01b

200

100

300

500

700

400

90

85

80

75

70

65

60

55

50