Datasheet

VIPER06
Burst mode
DocID022794 Rev 2
17/28
Figure 24: COMP pin voltage versus IDRAIN
13 Burst mode
When the voltage V
COMP
drops below the threshold, V
COMPL
, the power MOSFET is kept in
the OFF state and the consumption is reduced to the I
DD0
current, as reported on Table 6:
"Supply section ". In reaction to the loss of energy, the V
COMP
voltage increases and as
soon as it exceeds the threshold V
COMPL
+ V
COMPL_HYS
, the converter starts switching again
with a level of consumption equal to the I
DD1
current. This ON-OFF operation mode,
referred to as “burst mode” and shown in Figure 25: "Load-dependent operating modes:
timing waveforms", reduces the average frequency, which can go down even to a few
hundreds hertz, thus minimizing all frequency-related losses and making it easier to comply
with energy-saving regulations. During burst mode, the drain current limit is reduced to the
value I
Dlim_bm
(given in Table 7: "Controller section ") in order to avoid the audible noise
issue.
Figure 25: Load-dependent operating modes: timing waveforms