1

LTC1265/LTC1265-3.3/LTC1265-5

5.4V TO

12V

L1*

33

µH

0.1

Ω

5V

1A

††

220

µF

10V

1000pF

130pF

3900pF

1k

0.1

µF

†††

68

µF

20V

D1

†

SW

PGND

SGND

LTC1265-FO1

SHDN

*

**

†

††

†††

COILTRONICS CTX33-4

IRC LRC2010-01-R100-J

MBRS130LT3

AVX TPSE227K010

AVX TPSE686K020

LTC1265-5

+

+

Figure 1. High Efficiency Step-Down Converter

1.2A, High Efficiency

Step-Down DC/DC Converter

s

High Efficiency: Up to 95%

s

Current Mode Operation for Excellent Line and Load

Transient Response

s

Internal 0.3

s

Short-Circuit Protection

s

Low Dropout Operation: 100% Duty Cycle

s

Low-Battery Detector

s

Low 160

µA Standby Current at Light Loads

s

s

Peak Inductor Current Independent of Inductor Value

s

Available in 14-pin SO Package

The LTC

DC/DC converter featuring Burst Mode

output current. The LTC1265 incorporates a 0.3

Ω switch

Under no load condition, the converter draws only 160

µA.

In shutdown it typically draws a mere 5

µA making this

converter ideal for current sensitive applications. In drop-

out the internal P-channel MOSFET switch is turned on

continuously maximizing the life of the battery source. The

LTC1265 incorporates automatic power saving Burst Mode

operation to reduce gate charge losses when the load

currents drop below the level required for continuous

operation.

The inductor current is user-programmable via an external

current sense resistor. Operation up to 700kHz permits

the use of small surface mount inductors and capacitors.

s

5V to 3.3V Conversion

s

Distributed Power Systems

s

Step-Down Converters

s

Inverting Converters

s

Memory Backup Supply

s

Portable Instruments

s

Battery-Powered Equipment

s

Cellular Telephones

LTC1265-5 Efficiency

Burst Mode is a trademark of Linear Technology Corporation.

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

LOAD CURRENT (A)

0.01

70

75

80

85

90

100

0.10

1.00

LTC1265 TA01

95

L = 33

µH

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