1

LTC3772B

3772bfa

■

±1.5% Voltage Reference Accuracy

Transient Response

µA Supply Current in Shutdown

(3mm

× 2mm) DFN (0.75mm) Packages

550kHz Micropower Step-Down DC/DC Converter

The LTC

step-down DC/DC controller in a low profile 8-lead SOT-23

(ThinSOT

× 2mm DFN package. The No

sense resistor, improving efficiency and saving board

space.

The LTC3772B automatically switches into pulse skipping

operation at light loads. It consumes only 200

µA of quies-

cent current under a no-load condition.

The LTC3772B incorporates an undervoltage lockout fea-

ture that shuts down the device when the input voltage

falls below 2V. To maximize the runtime from a battery

source, the external P-channel MOSFET is turned on

continuously in dropout (100% duty cycle). High switch-

ing frequency of 550kHz allows the use of a small inductor

and capacitors. An internal soft-start smoothly ramps the

output voltage from zero to its regulation point.

LTC3772B

20k

82.5k

174k

22pF

680pF

GND

3772B TA01

SW

PGATE

10

µF

3.3

µH

2.75V TO 9.8V

2.5V

2A

47

µF

Efficiency and Power Loss vs Load Current

(Figure 5 Circuit)

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

Constant Frequency Step-Down

DC/DC Controller

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

All other trademarks are the property of their respective owners. Protected by

U.S. Patents including 5731694, 6127815.

LOAD CURRENT (mA)

30

90

100

20

10

80

50

70

60

40

1

100

1000

10000

3772B TA01b

0

10

0.01

1

0.1

0.001

10

EFFICIENCY

POWER LOSS