The circuit described here is a 12-V dc to 5-V dc (±5%) switched-mode power supply (SMPS). The supply uses a 12-V input from an array of four 3-V dc, 40-mA solar cells connected in series.

This project simulates a basic buck converter using LTspice. It takes a 12V DC input and steps it down to a ~5V DC output using a PWM-controlled NMOS transistor, an inductor, diode, and capacitor.

Circuit Analysis Figure 1 shows the schematic diagram. The heart of the circuit is the TPS54332DDA chip 1. According to the datasheet: “The TPS54332 is a 28-V, 3.5-A, step-down (buck) converter with ...