PIN FUNCTIONS

DIP

SO (*)

Name

Function

1

2

GND

Ground

2

3

VREF

5.1V Reference voltage with 20mA current capability.

3

4

OSC

An external resistor connected between the unregulated input voltage and this pin and

a capacitor connected from this pin to ground fix the switching frequency. (Line feed

forward is automatically obtained)

4

5, 6

OUT

Stepdown regulator output

511

Unregulated DC input voltage

6

12

BOOT

A capacitor connected between this pin and OUT allows to drive the internal VDMOS

7

13

COMP

E/A output to be used for frequency compensation

8

14

FB

Stepdown feedback input. Connecting directly to this pin results in an output voltage of

3.3V. An external resistive divider is required for higher output voltages.

(*) Pins 1, 7, 8, 9, 10, 15 and 16 are not internally, electrically connected to the die.

PIN CONNECTIONS

GND

OSC

OUT

1

3

2

4

VCC

BOOT

COMP

FB

8

7

6

5

N.C.

GND

OSC

OUT

N.C.

OUT

N.C.

N.C.

N.C.

BOOT

VCC

COMP

FB

N.C.

N.C.

1

3

2

4

5

6

7

8

14

13

12

11

10

9

15

16

VOLTAGES

MONITOR

THERMAL

SHUTDOWN

E/A

PWM

3.3V

OSCILLATOR

R

S

Q

INTERNAL

REFERENCE

5.1V

DRIVE

CBOOT

CHARGE

CBOOT

CHARGE

AT LIGHT

LOADS

2

7

8

FB

COMP

3

1

4

6

5

BOOT

OSC

GND

OUT

3.3V

BLOCK DIAGRAM

Minidip

SO16W

L4976

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