Datasheet

Pin settings L7986TA

4/43 Doc ID 022098 Rev 3

1 Pin settings

1.1 Pin connection

Figure 1. Pin connection (top view)

1.2 Pin description

Table 1. Pin description

N. Type Description

1 OUT Regulator output

2 SYNCH

Master/slave synchronization. When it is left floating, a signal with a

phase shift of half a period, with respect to the power turn-on, is present

at the pin. When connected to an external signal at a frequency higher

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

with zero phase shift.

Connecting together the SYNCH pin of two devices, the one with a higher

frequency works as master and the other as slave; so the two powers

turn-ons have a phase shift of half a period.

3EN

A logical signal (active high) enables the device. With EN higher than 1.2

V the device is ON and with EN lower than 0.3 V the device is OFF.

4 COMP Error amplifier output to be used for loop frequency compensation.

5FB

Feedback input. By connecting the output voltage directly to this pin the

output voltage is regulated at 0.6 V. To have higher regulated voltages an

external resistor divider is required from V

OUT

to the FB pin.

The switching frequency can be increased connecting an external

resistor from the FSW pin and ground. If this pin is left floating, the device

works at its free-running frequency of 250 kHz.

7 GND Ground

Unregulated DC input voltage.