electromagnetic emissions, with small impact on output voltage ripple.

The internal dithering circuitry changes the switching frequency in the range of ± 5% of the nominal value. The

device updates the frequency every clock period by fixed steps:

•

Ramps up in 63 steps from minimum to maximum switching frequency

•

Ramps down in 63 steps from maximum to minimum switching frequency

The resulting frequency modulation is almost triangular, with a frequency of:

FDitℎ=FSW126

(3)

L7983

Switching frequency programming and dithering

DS13354 - Rev 1

page 16/43