PIN FUNCTIONS

Powerdip

SO20

NAME

DESCRIPTION

11

12

COMP

E/A output to be used for frequency compensation

10

11

INH

A logic signal (active high) disables the device (sleep mode operation).

If not used it must be connected to GND; if floating the device is disabled.

9

10

BOOT

A capacitor connected between this pin and the output allows to drive the

internal D-MOS.

18

20

SYNC

Input/Output synchronization.

7,8

8,9

Vcc

Unregulated DC input voltage

2,3

2,3

OUT

Stepdown regulator output.

12

13

VFB

Stepdown feedback input. Connecting the output directly to this pin results

in an output voltage of 3.3V for the L4973V3.3 and 5.1V. An external

resistive divider is required for higher output voltages. For output voltage

less than 3.3V, see note ** and Figure 32.

16

18

V5.1

Reference voltage externally available.

4,5,6

13,14,15

4,5,6,7

14,15,16,17

GND

Signal ground

1

1

OSC

An external resistor connected between the unregulated input voltage and

Pin 1 and a capacitor connected from Pin 1 to ground fixes the switching

frequency. (Line feed forward is automatically obtained)

ABSOLUTE MAXIMUM RATINGS

Symbol

Parameter

Value

Unit

DIP-18

S0-20

Input voltage

58

V

Output DC voltage

Output peak voltage at t = 0.1

µs f=200KHz

-1

-5

V

V

Maximum output current

int. limit.

14

V

Bootstrap voltage

70

V

12

V

V19

13

V

6

-0.3

V

V

5.5

-0.3

V

V

Inhibit

Vcc

-0.3

V

V

≤ 90°C

°C no copper area)

°C 4cm copper area on PCB)

DIP

12+3+3

5

1.3

2

W

W

W

°C

SO20

4

W

Junction and storage temperature

-40 to 150

°C

THERMAL DATA

Symbol

Parameter

Powerdip

SO20

Unit

Thermal Resistance Junction to pin

Max.

12

15

°C/W

Thermal Resistance to Ambient

Max.

60 (*)

80 (*)

°C/W

(*) Package mounted on board.

L4973V3 - L4973V5 - L4973D3 - L4973D5

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