LT3570

1

3570fa

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

1.5A Buck Converter,

1.5A Boost Converter and

LDO Controller

The LT

power switches and LDO controller. Each converter is

designed with a 1.5A current limit and an input range

from 2.5V to 36V, making the LT3570 ideal for a wide

variety of applications. Switching frequencies up to 2MHz

are programmed with an external timing resistor and the

oscillator can be synchronized to an external clock up to

2.75MHz.

The LT3570 features a programmable soft-start function

that limits the feedback voltage during start-up helping

prevent overshoot and limiting inrush current. The LDO

controller is capable of delivering up to 10mA of base

current to an external NPN transistor.

Efficiency

from 500kHz to 2MHz

× 4mm) QFN and

20-Lead TSSOP Packages

SHDN1

SHDN2

SHDN3

SHDN1

SHDN2

SHDN3

SW1

FB1

100nF

1nF

10nF

22μF

2.2μF

2.5V

100mA

32.4k

3.3V

1A

22k

143k

12V

275mA

5V

22k

10.0k

10.2k

22.1k

10.2k

3570 TA01a

15.8k

10μF

10μF

1nF

10nF

3.3μH

6.8μH

D2

D3

D1

BOOST

SW2

FB2

SS2

NPN_DRV

FB3

SS1

SYNC

LT3570

GND

Q1

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

All other trademarks are the property of their respective owners.

0

70

75

80

85

90

95

100

0.2

0.4

0.6

0.8

3570 TA01b

1.0

VIN = 5V