L6591

Summary of L6591 power management functions

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Summary of L6591 power management functions

It has been seen 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 designer familiarize with these functions, in the

following tables all of theme are summarized with their respective activation mechanism 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

Pulse

skipping

operation

N.A.

2 mA max

when

Active (low)

when

No

change

Stopped

when

Adaptive

UVLO

Extended

Vcc range at

light load

UVLO

threshold

reduction

N.A.

N.A.

No change

No

change

Run

Table 6.

Protections

Protection

Description

Caused by

IC

behavior

Vcc

restart

[V]

IC Iq

[mA]

VREF

[V]

SS

[V]

OSC

[V]

PFC_STOP

OLP

Output

overload

protection

Auto

5

1.2

5

N.A.

0

Stop

Active (low)

Latched

13

0.35

max

0

N.A.

0

Stop

Active (low)

Short circuit

protection

Output short

circuit

protection

Auto

5

1.2

5

N.A.

0

Stop

Active (low)

Latched

13

0.35

max

0

N.A.

0

Stop

Active (low)