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Date: 07/20/05

SP6659 1.5MHz, 600mA Synchronous Buck Regulator

© Copyright 2005 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

■ 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

Preliminary

®

SP6659

4.7µF

Ceramic

GND

10µF

Ceramic

SW

2.2µH

R1

R2

RUN

C2

22pF

1

4

3

5

2

54

SP6659

5 Pin TSOT-23

VIN

GND

RUN

SW

VFB

12

3

54

SP6659

5 Pin TSOT-23

VIN

GND

RUN

SW

VOUT

12

3

Adjustable

Fixed

®

SP6659

4.7µF

Ceramic

GND

10µF

Ceramic

SW

2.2µH

4

3

5

2

Adjustable

Fixed