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