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  1. I saw the data sheet of the LTC3703 and there was a design example on page 27, i followed the same procedure. LTC3703 Data Sheet Specifications: VIN = 24V to 100V, VOUT = 12V, IOUT(Max) = 10A, f = 250kHz 1. RSET As per the formula in the data sheet RSET(kOhm) = 7100/(250 - 25) = 31.5KOhm -> eq1 2. Inductor value for about 40% ripple current at maximum VIN L = 12/250K*0.4*10(1 - 12/100) = 10.56uH. -> eq2 3. Minimum On-time ton(min) = 12/(100*250kHz) = 480nS -> eq3 which is above LTC3703's 200ns Minimum on-time. 4. Top and Bottom MOSFET switch Since the drain of each MOSFET will see the full supply voltage 100V (max) plus any ringing, choose a 125V MOSFET to provide a margin of safety. PMAIN = 1.32W -> eq4 = 96.4DegC. =1.84 -> eq5 TJ = 70 + 1.84*20 = 106.8 5. Current Limit Resistor RDS(ON) = (25mOhm)/2 [1 + 0.009(105 - 25)] = 21.5mOhm IMAX pin voltage = 10*0.0215 = 0.215V RMAX = 0.215/12uA = 18k -> eq6 6. CIN is chosen for an RMS current rating of 5A (IMAX/2) at 85DegC. 7. For the output capacitor 2 low ESR OS-CON capacitors (18mF) are used. The LTSPICE model is in progress, i have completed to the below level, the work is still in progress, i also need to choose the MOSFET. But based on the above steps, could you please provide comments. design.pdf
  2. I have started going through the data sheet and trying to download ltspice simulation models for buck converter, but the above circuit i could not locate, have you created on your own? just for information.
  3. Thank you for the reply, by help from other forums online i selected LTC3703 regulator, and from the application note in the data sheet https://pdf1.alldatasheet.com/datasheet-pdf/view/97352/LINER/LTC3703.html Can i use this circuit as is to meet the requirements i mentioned? I want current upto 10 Amps, can i change the circuit accordingly? Please advise.
  4. I need to design a buck converter with the following requirements, Input voltage 24V - 100V (2 - 10 Amps) and the output voltage shall be 12V (20 Amps). I started with the following circuit available in the net. The Diode, Inductor, Capacitor i have not yet selected, First question is how do i switch the MOSFET, do i need to interface a micro controller to calculate the duty cycle based on the output current, input voltage? I am new to hardware design. Please help.
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