AN1518

Pin functions

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1

Pin functions

1.1

Pin description

2

Block diagram

Figure 4.

Block diagram

Table 1.

Pin functions

N.

Name

Description

1

OUT

Regulator output

2

SYNC

Master/slave synchronization. When open, a signal synchronous with the turn-OFF of the

internal power is present. When connected to an external signal at a frequency higher than

the internal one, the device is synchronized by the external signal.

Connecting the SYNC pins 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 an IHN higher than 2.2 V the device is

OFF and with an INH lower than 0.8 V, 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

Step-down feedback input. Connecting the output voltage directly to this pin results in an

output voltage of 1.235 V. An external resistor divider is required for higher output voltages

(the typical value for the resistor connected between this pin and ground is 4.7 k).

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

7

GND

Ground

Unregulated DC input voltage