Akanimo
Advanced Member level 3
Okay. If the Vf is between 3.3V and 5V, whatever the Vf is, and if you are sure that you want Vout of 5V, then you need a resistor of (Vout-Vf)/20mA in series with the LED at the output. You have to realize that that resistor is going to contribute to some power loss and, consequently, drop in efficiency.
Now, let's discuss the reference voltage. For this purpose, I'd recommend a 2.5V zener diode. This means that you will have equal resistances in the output voltage resistive divider circuit.
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22k or 27k should do for each of the two resistors.
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Now, we need to select an inductance value. Which conduction mode do you prefer? CCM or DCM?
Now, let's discuss the reference voltage. For this purpose, I'd recommend a 2.5V zener diode. This means that you will have equal resistances in the output voltage resistive divider circuit.
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22k or 27k should do for each of the two resistors.
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Now, we need to select an inductance value. Which conduction mode do you prefer? CCM or DCM?