Datasheet

L6730 - L6730B Device description
Doc ID 11938 Rev 3 23/52
There is an electrical network between the output terminal and the FB pin and therefore the
voltage at this pin is not a perfect replica of the output voltage. If the converter can sink
current, in the most of cases the low-side will be turned on before the output voltage
exceeds the over-voltage threshold because the error amplifier will throw off balance in
advance.
Even if the device does not report an overvoltage event, the behavior is the same because
the low-side is turned on immediately. Instead, if the sink mode is disabled, the low-side will
be turned on only when the overvoltage protection (OVP) operates and not before because
the current can not be reversed. In this case, a delay between the output voltage rising and
FB voltage rising can appear and the OVP can turn on late. Figure 17 and Figure 18 show
an overvoltage event in the cases of the sink being enabled or disabled. The output voltage
rises with a slope of 100 mVµs, emulating the breaking of the high-side MOSFET as an
overvoltage occurs.
Figure 16. OVP latched
LGate
OSC
FB