Power Supply Comparisons

Linear Power Supply vs. Switching Power Supply vs. Unregulated Power Supply

  Switching Regulated
Power Supplies
Linear Regulated
Power Supplies
Unregulated
Power Supplies
Circuit Design complex moderately complex simple
Part Count
high medium low
Load Regulation
0.05% to 0.5% .005% to 0.2% +10% (1/2 load to No Load (NL))
-10% (1/2 load to Full Load (FL))
Line Regulation 0.05% to 0.2% 0.005% to 0.05% directly proportional to
AC input change
Ripple (RMS) 10 mv to 25 mv 0.25 mv to 1.5 mv 0.5 v to 5 v
Transient
Recovery
300 microseconds
(1/2L to FL)
50-100 microseconds
(NL to FL)
N/A
Efficiency 70-85% 40-60% 90-95%
Hold-up Time 15-30 milliseconds 1-2 milliseconds  
EMI high very low very low
Leakage high low very low
Size
(power density)
small size
(high power density)
large size
(low power density)
medium size
(medium power density)
Weight
(Power to Weight Ratio)
light
(high)
heaviest
(low)
heavy
(low)
Power Factor 0.6 - 0.7 without PFC
>0.95 with PFC
0.6 - 0.7  0.6 - 0.7 
Cooling convection or fan convection or fan convection
Isolation yes yes yes
Input Voltage
Range
90 - 132 VAC
(without PFC)

     and/or

180 - 264 VAC
(without PFC)

-----------------
90 - 264 VAC
(with PFC)
105 - 125 VAC
     and/or
210 - 250 VAC 
0 - 125 VAC
0 - 250 VAC
Output directly
proportional to input
Values in chart above are for comparison purposes only.
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