
SAMLEX AMERICA INC. | 15
Input voltage
Inrush current
Peak inrush
current
Rated steady state
input RMS current
NOTE:
Voltage
and current scales
are different
Fig 4.1: Inrush current in an SMPS
TIME
Peak Current
RMS Current
Non-linear
Input Current
Pulse
Input Sine
Wave Voltage
Crest Factor = Peak Current = 3
RMS Current
V
oltage (+)
V
oltage (–)
C
u
rr
ent (+)
C
u
rr
ent (–)
NOTE:
Voltage
and current scales
are different
Fig. 4.2: High Crest Factor of current drawn by SMPS
SECTION 4 |
Powering Direct / Embedded Switch
Mode Power Supplies (SMPS)