1

LTC3822

3822f

LOAD CURRENT (mA)

100

100

90

80

70

60

50

40

30

20

10

0

10

1

0.1

0.01

1000

10000

3822 TA01b

EFFICIENCY

POWER LOSS

47

µF

2.75V TO 4.5V

1.8V

8A

3822 TA01

5.1k

680pF

IPRG

FREQ

SW

BOOST

TG

RUN

BG

GND

LTC3822

59k

0.22

µF

0.47

µH

100

µF

FDS6898A

118k

Voltage, Synchronous Step-Down

DC/DC Controller

■

No Current Sense Resistor Required

■

Constant Frequency Current Mode Operation for

Excellent Line and Load Transient Response

■

±1% 0.6V Reference

■

Internal Soft-Start Circuitry

■

Output Overvoltage Protection

DFN or 10-Lead MSOP Package

1.8V/8A High Efficiency, 550kHz Step-Down Converter

DESCRIPTIO

FEATURES

TYPICAL APPLICATIO

The LTC3822 is a synchronous step-down switching

regulator controller that drives external N-channel power

MOSFETs using few external components. The constant

sensing eliminates the need for sense resistors and im-

proves efficiency.

A maximum duty cycle of 99% provides low dropout

operation. The switching frequency can be programmed

up to 750kHz, allowing the use of small surface mount

inductors and capacitors.

The LTC3822 is available in thermally enhanced DFN and

10-lead MSOP packages.

APPLICATIO S

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

property of their respective owners. Protected by U.S. Patents, including 5481178,

5929620, 6580258, 6304066, 5847554, 6611131, 6498466.

Efficiency and Power Loss vs

Load Current