Category: Hardware
Product Number: LT1072
I want to convert -48V DC fromtelecom power to +5V DC, I'm considering this schematic:
Sometimes rectifier output of telecom is -54 DC,hence I'm considering this schematic for -40V to -60V input.
I've calculated R1 and R2 using this formula:
R1= R2*(Vout-Vbe)/Vref
where, Vout = 5, Vbe= 0.6, Vref= 1.244
But when I simulated this schematic in LTspice, the output was +5.55V.
But I want it to 4.9V~5.2V. This +5V DC will be used for runnning microcontroller, sensors, and provide boolean output (+5V). How to solve this?
Besides this I want to know how to calculate the value of inductor (L1), for 1A and 1.25A. I went through the datasheet, but that was confusing to me.