1

LT1306

APPLICATIO S

DESCRIPTIO

FEATURES

Synchronous, Fixed Frequency

Step-Up DC/DC Converter

s

Output Disconnected from Input During Shutdown

s

Output Voltage Remains Regulated

s

Controlled Input Current During Start-Up

s

300kHz Current Mode PWM Operation

s

Can Be Externally Synchronized

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Internal 2A Switches

s

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Automatic Burst Mode Operation at Light Loads

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Quiescent Current: 160

µA

s

Shutdown Current: 9

µA Typ

The LT

chronous boost converter capable of generating 5V at 1A

from a Li-Ion cell. The device contains both the main

power switch and synchronous rectifier on chip and

automatically disconnects the output from the input in

shutdown, eliminating the need for external load discon-

nect circuitry. Additionally, the output remains regulated

down converter functions to be easily realized using a

single inductor.

The internal 300kHz oscillator of the LT1306 can be easily

synchronized to an external clock from 425kHz to 500kHz.

This allows switching harmonics to be tightly controlled

and eliminates any beat frequencies that may result from

a multifrequency system. The LT1306 automatically shifts

into power saving Burst Mode

At heavy loads the LT1306 operates in fixed frequency

current mode. No-load quiescent current is 160

µA and

reduces to 9

µA in shutdown mode.

The LT1306 is available in an SO-8 package.

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

Burst Mode is a trademark of Linear Technology Corporation.

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Satellite Phones

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Portable Instruments

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Personal Digital Assistants

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Palmtop Computers

LOAD CURRENT (mA)

1

60

80

85

90

10

100

1000

1306 TA01

75

70

65

L1 = 10

µH

(FIGURE 1)

SW

L1

10

µH

D1

C1

1

µF

CAP

LT1306

R3

118k

R2

249k

R1

768k

68nF

0.1

µF

22

µF

1-CELL

Li-Ion

68pF

1

µF

220

µF

C1: AVX TAJA105K020

D1: MMBD914LT1

L1: CTX10-2

1306 F01

5V

1A

OUT

S/S

FB

GND

+

+

Efficiency

Figure 1. Single Li-Ion Cell to 5V Converter