6.1.1.3 Low Drop Out Regulators vs. Buck Converters

In this video the energy efficiencies of Low Drop Out (LDO) regulators and Buck converters is discussed. A quick graph is generated in Sage Mathematics to compare the two circuits power consumption

LDO Efficiency:

$$P_{loss}=I*(V_{in}-V_{out})$$

Where $P_{loss}$ is heat dissipation, $I$ is the current drawn on the output, $V_{in}$ is the input voltage, and $V_{out}$ is the output voltage.

Buck Efficiency:

$$P_{loss}=(1-E)*V_{out}*I$$

Where $P_{loss}$ is heat dissipation, $E$ is the calculated efficiency, $I$ is the current drawn on the output, and $V_{out}$ is the output voltage.

Sage Simulation Script:

var("Vin",latex_name="V_{in}")
var("Vout",latex_name="V_{out}")
var("I")
var("E")
Vin=17
Vout=12
E=.87
PlossLDO=I*(Vin-Vout)
PlossBuck=Vout*I*(1-E)
plot(PlossLDO,(I,0,1.5))+plot(PlossBuck,(1,0,1.5),color="red")

References: