L5973AD

Pin settings

3/21

1

Pin settings

1.1

Pin connection

Figure 1.

Pin connection (top view)

1.2

Pin description

OUT

SYNC

INH

COMP

1

3

2

4

VCC

VREF

GND

FB

8

7

6

5

D98IN955

Table 1. Pin description

N°

Type

Description

1

OUT

Regulator output.

2

SYNC

Master/Slave Synchronization. When it is open, a signal synchronous with the

turn-off of the internal power is present at the pin. When connected to an

external signal at a frequency higher than the internal one, then the device is

synchronized by the external signal.

Connecting together the SYNC pin of two devices, the one with the higher

frequency works as master and the other one, works as slave.

3INH

A logical signal (active high) disables the device. With IHN higher than 2.2V

the device is OFF and with INH lower than 0.8V, the device is ON.

If INH is not used the pin must be grounded. When it is open, an internal pull-

up disables the device.

4

COMP

E/A output to be used for frequency compensation.

5FB

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

results in an output voltage of 1.235V. An external resistor divider is required

for higher output voltages (the typical value for the resistor connected

between this pin and ground is 4.7K).

6

VREF

Reference voltage of 3.3V. No filter capacitor is needed to stability.

7

GND

Ground.

8

VCC

Unregulated DC input voltage.