L6722

9 Output voltage monitor and protections

25/34

threshold is crossed, all mosfets are turned off, the FAULT pin is driven high and the device

stops working. Cycle the power supply or the INH pin to restart operation.

The maximum average current during the Constant-Current behavior results:

in this particular situation, the switching frequency for each phase results reduced. The ON time

bottom of the inductor current ripple and also considering the additional current delivered

during the quasi-constant-current behavior as previously described in the worst case

conditions.

where

Figure 14. Constant current operation

PEAK

I

OCPx

V

IN

V

OUT min

()

–

L

-------------------------------------------

T

ON max

()

⋅

+

I

OCPx

V

IN

V

OUT min

()

–

L

-------------------------------------------

0.40

T

⋅

SW

⋅

+

==

MAX tot

,

3I

MAX

⋅

3I

OCPx

I

PEAK

I

OCPx

–

2

-------------------------------------

+

⎝

⎠

⎛

⎞

⋅

==

T

OFF

L

I

PEAK

I

OCPx

–

V

OUT

-------------------------------------

⋅

=

f

1

T

ON max

()

T

OFF

+

----------------------------------------------

=

R

ISENx

I

OCPx max

()

R

dsON max

()

⋅

I

OCTH min

()

---------------------------------------------------------------------

=

I

OCPx

I

OUT OCP

()

3

----------------------------

∆I

PP

2

------------

–

=

Constant Current (Exploded)

UVP Threshold

Resulting Out. Char.

Droop Effect

LS ON Skipping

Clock Cycles