L5973AD
Pin settings
1
1.1
Pin settings
Pin connection
Figure 1.
Pin connection
(top view)
OUT
SYNC
INH
COMP
1
2
3
4
D98IN955
8
7
6
5
VCC
GND
VREF
FB
1.2
Pin description
Table 1. Pin description
N°
1
Type
OUT
Regulator output.
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.
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.
E/A output to be used for frequency compensation.
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).
Reference voltage of 3.3V. No filter capacitor is needed to stability.
Ground.
Unregulated DC input voltage.
Description
2
SYNC
3
INH
4
COMP
5
FB
6
7
8
VREF
GND
VCC
3/21
STMICROELECTRONICS [ STMICROELECTRONICS ]
