ECE 556 Lab 5 Pre-Lab Calculations
Problem 1
Design a continuous mode buck-boost switching regulator with the following specifications:
• 12 V ≤ Vin ≤ 14 V
• Vo = -25 V
• Io ≤ 2 A
Available Parts
1. Coilcraft p/n PCV-2-274-10, 270 µH Inductor
2. Coilcraft p/n PCV-2-394-05L, 394 µH Inductor
3. Coilcraft p/n PCV-2-564-08L, 564 µH Inductor
4. 10,000 µF Capacitor
Specify the following items in your design:
• Inductor: inductance value, peak current, average current.
• Capacitor: capacitance value, RMS ripple current, voltage rating
• Diode: peak current, RMS current
Turn in:
• A MathCAD or Maple file that documents every calculation and the choice of each part. This file should be designed so
that you can easily change the design parameters so that you can use it to design other buck-boost DC-DC converters.
You should be able to change the switching frequency, input voltage, output voltage, and output power (or current).
• Turn in datasheets for your inductor and capacitor with the values highlighted.
• The following PSpice simulations.
1. Output voltage at full load for minimum input voltage.
2. Inductor current at full load for minimum input voltage.
3. Output voltage at full load for maximum input voltage.
4. Inductor current at full load for maximum input voltage.
For the simulations, you must simulate the feedback control using a comparator and an error amp using the ABM parts. Start
with a capacitor initial condition of zero. Include capacitor ESR in your simulations.