Datasheet

Pin settings L5987
4/41 Doc ID 14972 Rev 3
1 Pin settings
1.1 Pin connection
Figure 2. Pin connection (top view)
1.2 Pin description
OUT
SYNCH
INH
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
INH
COMP
V
CC
GND
FSW
FB
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 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, then the device is synchronized by the external signal, with
zero phase shift.
Connecting together the SYNCH pin of two devices, the one with higher
frequency works as master and the other one as slave; so the two
powers turn on have a phase shift of half a period.
3INH
A logical signal (active high) disable the device. With INH higher than
1.9 V the device is OFF and with INH lower than 0.6 V the device is ON.
4 COMP Error amplifier output to be used for loop frequency compensation
5FB
Feedback input. 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 Vout to FB pin.
6F
SW
The switching frequency can be increased connecting an external
resistor from FSW pin and ground. If this pin is left floating the device
works at its free-running frequency of 250 kHz.
7 GND Ground
8V
CC
Unregulated DC input voltage