Datasheet

Pin settings L7985
4/43 Doc ID 022446 Rev 3
1 Pin settings
1.1 Pin connection
Figure 2. Pin connection (top view)
1.2 Pin description
OUT
SYNCH
EN
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
COMP
V
CC
GND
FSW
FB
OUT
V
CC
V
CC
OUT
SYNCH
EN
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
COMP
V
CC
GND
FSW
FB
VFQFPN10
HSOP8
OUT
SYNCH
EN
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
COMP
V
CC
GND
FSW
FB
OUT
V
CC
V
CC
OUT
SYNCH
EN
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
COMP
V
CC
GND
FSW
FB
OUT
V
CC
V
CC
OUT
SYNCH
EN
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
EN
COMP
V
CC
GND
FSW
FB
OUT
SYNCH
COMP
V
CC
GND
FSW
FB
VFQFPN10
HSOP8
Table 1. Pin description
N.
(VFQFPN)
N.
(HSOP)
Type Description
1-2 1 OUT Regulator output
3 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 one
as slave; so the two power turn-ons have a phase shift of
half a period.
43EN
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.
54COMP
Error amplifier output to be used for loop frequency
compensation.
65FB
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.
76F
SW
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.
8 7 GND Ground
9-10 8 V
CC
Unregulated DC input voltage.