Datasheet

Summary of L6591 power management functions L6591
34/41 Doc ID 14821 Rev 6
7 Summary of L6591 power management functions
It has been shown that the device is provided with a number of power management
functions: different operating mode upon loading conditions, protection functions, as well as
interaction with the PFC pre-regulator. To help the user familiarize themselves with these
functions, in the following tables all of the themes are summarized with their respective
activation mechanisms and the resulting status of the most important pins. This can be
useful not only for a correct use of the IC but also for diagnostic purposes: especially at
prototyping/debugging stage; it is quite common to bump into unwanted activation of some
function, and these tables can be used as a sort of quick troubleshooting guide.
Table 5. Light load management
Feature Description Caused by
IC
behavior
Vcc
restart
[V]
Consumption
[mA]
PFC_STOP SS OSC
Burst mode
Controlled
ON-OFF
operation for
low power
consumption
at light load
V
COMP
<
V
COMPBon
Pulse
skipping
operation
N.A.
2 mA max.
when
V
COMP
<
V
COMPBon
Active (low)
when
V
COMP
<
V
COMPBon
No
change
Stopped
when
V
COMP
<
V
COMPBon
Adaptive
UVLO
Extended
Vcc range at
light load
V
COMP
<
V
COMPL
UVLO
threshold
reduction
N.A. N.A. No change
No
change
Run
Table 6. Protection
Protection Description Caused by
IC
behavior
Vcc
restart
[V]
IC Iq
[mA]
VREF
[V]
SS
V
COMP
[V]
OSC
[V]
PFC_STOP
OLP
Output
overload
protection
V
COMP
=
V
COMPH
V
SS
>
V
SSDIS
Auto-
restart
(1)
5 1.2 5 N.A. 0 Stop Active (low)
V
COMP
=
V
COMPH
V
SS
>
V
SSLAT
Latched 13
0.35
max.
0 N.A. 0 Stop Active (low)
Short-
circuit
protection
Output short-
circuit
protection
V
COMP
=
V
COMPH
V
SS
>
V
SSDIS
Auto-
restart
(1)
5 1.2 5 N.A. 0 Stop Active (low)
V
COMP
=
V
COMPH
V
SS
>
V
SSLAT
Latched 13
0.35
max.
0 N.A. 0 Stop Active (low)