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Date: 9/25/06 Rev C

SP6659 1.5MHz, 600mA Synchronous Buck Regulator

© 2006 Sipex Corporation

SP6659

The SP6659 is a 600mA synchronous buck regulator using a constant frequency, current mode

architecture. The output voltage can be programmed using an external resistor divider. The 2.5V

to 5.5V input voltage range is ideal for portable applications that use a Li-Ion battery. Switching

frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and

capacitors. The internal synchronous switch increases efficiency and eliminates the need for an

external Schottky diode. The output voltage can be programmed using an external resistor

divider. Low output voltages are easily supported with the 0.6V feedback reference voltage. The

SP6659 is available in a low profile 5 pin TSOT-23 package.

DESCRIPTION

FEATURES

■ 94% Efficiency Possible

■ 600mA Output Current at V

■ 2.5V to 5.5V Input Voltage Range

■ 1.5MHz constant frequency operation

■ No Schottky Diode Required

■ Output Voltages as low as 0.6V

■ Slope Compensated Current Mode

Operation for Excellent Line and Load

Transient Response

■ 100 % Duty Cycle in LDO Mode

■ <1μA Shutdown Current, Quiescent

Current of 300 μA

■ Over-temperature protected

■ Pin Compatible to LTC3406B

■ Offered in Low Profile TSOT-23

package

APPLICATIONS

■ Cell Phones

■ Wireless and DSL Modems

■ DSC's

■ Portable Instruments

TYPICAL APPLICATION SCHEMATICS

Now Available in Lead Free Packaging

1.5MHz, 600mA Synchronous Buck Regulator

®

SP6659

4.7μF

Ceramic

GND

10μF

Ceramic

SW

2.2μH

R1

R2

RUN

Cf

100pF

1

4

3

5

2

5

4

SP6659

5 Pin TSOT-23

VIN

GND

RUN

SW

VFB

1

2

3

5

4

SP6659

5 Pin TSOT-23

VIN

GND

RUN

SW

VOUT

1

2

3

Adjustable

Fixed

®

SP6659

4.7μF

Ceramic

GND

10μF

Ceramic

SW

2.2μH

4

3

5

2

Adjustable

Fixed