A synchronous buck converter based on a DrMOS device is designed and characterized. The effect of diode emulation mode on light-load power efficiency and ringing at the switching node is evaluated by measurements. The power efficiency is measured for different switching frequencies, output voltages and load currents. The measurement results show that the diode emulation mode increases the light-load efficiency by nearly 50% under certain operating conditions. The ringing observed at the switching node during the diode emulation mode causes an increase in the coupling between the designed converter and the transverse electromagnetic cell by up to 15 dB.