This board demonstrates a +12 V AC/DC buck and −12 V AC/DC non-isolated buck/boost-mode SMPS that can be used to supply up to 2.5 W into a load. Operation in buck or buck/boost-mode can be selected with the on-board jumper.
The switch mode converter operates at a maximum frequency of around 50 kHz.
Overcurrent and short-circuit protection are built in. Under no-load conditions, the power consumption of this converter is in the range of 10 mW. EMI filtering and (optional) surge voltage protection using TVS diodes is implemented in this circuit.