7 Output voltage positioning

L6722

20/34

7.3

Maximum duty cycle limitation

To provide proper time for current-reading in order to equalize the current carried by each

phase, the device implements a duty-cycle limitation. This limitation is not fixed but it is linearly

variable with the current delivered to the load as follow:

Duty Cycle limitation is variable with the delivered current to provide fast load transient

response at light load as well as assuring robust over-current protection.

Figure 10 shows the maximum output voltage that the device is able to regulate considering the

cross-point. In this case, the output voltage starts to decrease following the resulting

Figure 10. Maximum duty-cycle limitation

T

ON max

()

0.80

T

SW

I

ISENx

0

µA

=

⋅

0.40

T

SW

I

ISENx

35

µA

=

⋅

⎩

⎨

⎧

=

Maximum Output Voltage

Desired output Char.

UVP Threshold

Resulting Output Char.