L6920

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Trace1: Vout (50mV~/div) Trace 4: IL (100mA/div)

Time div.: 5

µs/div

Figure 8. Heavier load - Train pulses overlapping.

Time div.: 10

µs/div

Figure 9. Heavy load - Inductor current ripples

(200mA/div) Time div.: 20

µs/div

Figure 10. Heavy load and High ESR. Regulation

falls in continuous mode of operation. Trace1:

div.: 5

µs/div

When Iload is heavier, the pulse trains are overlapped. Figures 7 - 8 show some possible behaviors.

Considering that current in the inductor is limited to 1A, the maximum load current is defined by the following

relationship:

eq. (1)

Where

Of course, if Iload is greater than Iload_lim the regulation is lost (figure 11).

I

load_lim

V

in

V

out

-----------

I

–

V

out

V

in

–

2L

⋅

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

⋅

⎝⎠

⎛⎞ η

⋅⋅

=