A compact board-mounted power supply module for telecommunications systems

The authors describe the circuit and components of a compact board-mounted power supply module. A single-ended forward converter without a reset circuit reduces transformer size and circuit power dissipation. A simple, wideband optoisolation circuit extends the feedback loop bandwidth and reduces the size of the output smoothing filter. A low-profile surface-mounted transformer allows the power supply module to be mounted on a 15 mm-pitch circuit board. The 10 W power supply module can be reduced to 20 cm³, which is half the conventional size