Datasheet

I
BOUNDARY
=
(V
IN
± V
OUT
) x D
2 x L x f
SW
LM20134, LM20134Q
www.ti.com SNVS527G –OCTOBER 2007–REVISED MARCH 2013
(1)
Several diagrams are shown in Figure 27 illustrating continuous conduction mode (CCM), discontinuous
conduction mode, and the boundary condition.
It can be seen that in diode emulation mode, whenever the inductor current reaches zero the SW node will
become high impedance. Ringing will occur on this pin as a result of the LC tank circuit formed by the inductor
and the parasitic capacitance at the node. If this ringing is of concern an additional RC snubber circuit can be
added from the switch node to ground.
At very light loads, usually below 100mA, several pulses may be skipped in between switching cycles, effectively
reducing the switching frequency and further improving light-load efficiency.
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