Data Sheet

WPMDH1152401 / 171012402
MagI
3
C Power Module
VDRM – Variable Step Down Regulator Module
we-online.com Würth Elektronik eiSos GmbH & Co. KG – Data Sheet Rev. 2.0
© December 2017
33/54
In CCM, current flows through the inductor through the entire switching cycle and never falls to zero during the off-time. The
switching frequency remains relatively constant with load current and line voltage variations. The CCM operating frequency
can be calculated using the equation below.
The load current where the transition between DCM and CCM takes place can be estimated using the following formula:
I
OUT(DCM)
=
V
OUT
∙ 1-
V
OUT
V
IN

2∙f
SW
∙L
(22)
0
1
2
3
0 2 4 6 8 10 12 14 16 18 20
Inductor Current [A]
Time [µs]
Inductor Current Ripple V
IN
= 24V, V
OUT
= 12V, I
OUT
= 2A
2µs
f
SW
= 500kHz
∆I
L
= 0.8A