LTC3670

1

3670f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

Monolithic 400mA Buck

Regulator with Dual 150mA

LDOs in 3mm

× 2mm DFN

The LTC

400mA synchronous buck regulator and two 150mA low

dropout linear regulators (LDOs). The input supply range

of 2.5V to 5.5V is especially well-suited for single-cell

Lithium-Ion and Lithium-Ion/Polymer applications, and

for powering low voltage ASICs and SoCs from 3V, 3.3V

or 5V rails. Regulated output voltages are programmed

via external resistors. Each output has its own enable pin

for maximum flexibility.

The 400mA buck regulator features constant-frequency

2.25MHz operation, allowing small surface mount induc-

tors and capacitors to be used. Burst Mode operation

maintains high efficiency in light-load and no-load con-

ditions. Internal control-loop compensation simplifies

application design.

The LTC3670 is available in a 0.75mm profile, 3mm

×

2mm 12-lead DFN package.

Triple Power Supply with Independent Enables

Transient Response

× 2mm × 0.75mm DFN Package

CPLDs, ASICs, SoCs, CPUs and RF Chipsets

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

All other trademarks are the property of their respective owners. Patents pending.

LTC3670

3.3V TO 5.5V

SW

4.7μH

232k

2.2μF

464k

1.2V

400mA

10pF

4.7μF

BUCKFB

GND

ENBUCK

ENLDO1

ENLDO2

PGOOD

LDO1

LDO1_FB

DIGITAL

CONTROL

LDO2_FB

806k

324k

2.8V

150mA

1μF

LDO2

1.02M

324k

3.3V

150mA

1μF

3670 TA01a

Demoboard

3670 TA01b

9.4mm

ACTIVE AREA

9.3mm