Design of Portable Multiple Outputs Adjustable DC Power Supply

Adjustable DC power supplies are essential tools in electronic laboratories, offering precise control over voltage (CV mode) and current (CC mode) to meet various testing needs. This paper presents the design of a portable, multiple-output, adjustable DC power supply based on synchronous Buck and Buck-Boost converter topologies. Powered by a Li-ion battery pack (two batteries in series), the system delivers four distinct DC voltages: 3.3V, 5V, 12V, and −12V. Each output channel features independent constant current control logic, allowing for adjustable current limits or current sourcing. A Type-II feedback compensation network is used to limit the op-amp's bandwidth. Reference voltages are delivered by DACs that are controlled by MCU. To generate negative voltage, a variation a Buck topology circuit is used. Results demonstrate an output error margin of 0.46% for the 3.3V channel, 0.40% for the 5V, 0.10% for the −12V channels and 0.02% for the 12V channel. The system can provide up to 5A of current with an efficiency approaching 90%.