A switched-mode power supply includes an input, an output, and a transformer including primary and secondary windings. The power supply also includes a synchronous rectifier coupled to selectively conduct current through the secondary winding of the transformer. The synchronous rectifier includes a source, a gate and a drain terminal. The power supply further includes a controller having a supply voltage terminal and a gate terminal to supply a control signal to the gate of the synchronous rectifier, and a circuit coupled between the supply voltage terminal of the controller and at least one of the gate terminal of the controller and the drain terminal of the synchronous rectifier to supply power from the gate terminal of the controller or the drain terminal of the synchronous rectifier to the supply voltage terminal of the controller. Methods of supplying power in switched-mode power supplies are also disclosed.