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L5972D

May 2003

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2A INTERNAL SWITCH

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OPERATING INPUT VOLTAGE FROM 4.4V

TO 36V

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OUTPUT VOLTAGE ADJUSTABLE FROM

1.235V TO 35V

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LOW DROPOUT OPERATION: 100% DUTY

CYCLE

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250KHz INTERNALLY FIXED FREQUENCY

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VOLTAGE FEEDFORWARD

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ZERO LOAD CURRENT OPERATION

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INTERNAL CURRENT LIMITING

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PROTECTION AGAINST FEEDBACK

DISCONNECTION

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THERMAL SHUTDOWN

APPLICATIONS:

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CONSUMER: STB, DVD, TV, VCR,CAR

RADIO, LCD MONITORS

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NETWORKING: XDSL, MODEMS,DC-DC

MODULES

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COMPUTER: PRINTERS, AUDIO/GRAPHIC

CARDS, OPTICAL STORAGE, HARD DISK

DRIVE

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INDUSTRIAL: CHARGERS, CAR BATTERY

DC-DC CONVERTERS

DESCRIPTION

The L5972D is a step down monolithic power switch-

ing regulator with a minimum switch current limit of

2A so it is able to deliver more than 1.5A DC current

to the load depending on the application conditions.

The output voltage can be set from 1.235V to 35V.

The device uses an internal P-Channel D-MOS tran-

sistor (with a typical Rdson of 250m

Ω) as switching

element to minimize the size of the external compo-

nents.

An internal oscillator fixes the switching frequency at

250KHz.

Having a minimum input voltage of 4.4V only, it is

particularly suitable for 5V bus, available in all com-

puter related applications.

Pulse by pulse current limit with the internal frequen-

cy modulation offers an effective constant current

short circuit protection.

SO8 (4+2+2)

ORDERING NUMBERS: L5972D (SO8)

L5972D013TR (Tape & Reel)

2A SWITCH STEP DOWN SWITCHING REGULATOR

TEST APPLICATION CIRCUIT

D03IN1436

8

2

4

5

1

7

L5972D

C1

10

µF

35V

CERAMIC

C2

100

µF

10V

VOUT=3.3V

VIN = 4.4V to 35V

R1

5.6K

R2

3.3K

R3

4.7K

C4

22nF

C3

220pF

3

L1 33

µH

6

D1

STPS2L40U

COMP

VCC

OUT

FB

GND