L6712A L6712

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usual way until another OCP event is detected.

This means that the average current delivered can slightly increase also in Over Current condition since

the current ripple increases. In fact, the ON time increases due to the OFF time rise because of the current

When this happens, the device works in Constant Current and the output voltage decrease as the load

increase. Crossing the UVP threshold causes the device to reset.

Figure 10 shows this working condition.

The device works in Constant-Current, and the output voltage decreases as the load increase, until the

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

In this particular situation, the switching frequency results reduced. The ON time is the maximum allowed

Figure 10. Constant Current operation

centage with respect to the load value, it can be simply considered that, for example, to have on OCP

Once the UVP threshold has been intercepted, the device resets with all power mosfets turned OFF. An-

other soft start is then performed allowing the device to recover from OCP once the over load cause has

been removed.

Crossing the UVP threshold causes the device to reset: all mosfets are turned off and a new soft start is

I

peak

I

OCPx

V

IN

Vout

min

–

L

-------------------------------------- Ton

MAX

I

OCPx

V

IN

Vout

MIN

–

L

--------------------------------------- 0.40 T

⋅⋅

+

=

⋅

+

=

I

MAX,TOT

2I

MAX

2I

OCPx

Ipeak

I

OCPx

–

2

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

+

⎝⎠

⎛⎞

⋅

=

⋅

=

T

OFF

L

Ipeak

I

OCPx

–

V

OUt

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

f

1

T

ONmax

T

OFF

+

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

=

⋅

=

a) Maximum current for each phase

b) Output Characteristic

TonMAX

TonMAX

Ipeak

Vout

Iout

UVP

Droop effect