Embodiments described herein a method for controlling operating frequency for a wireless power charging system. Specifically, a transmitter coil at a wireless power transmitter is driven under an operating frequency and an input voltage. Deadtime information at the wireless power receiver is received, from a wireless power receiver having a receiver coil that receives wireless power from the transmitter coil. A microcontroller then determines, based on the received deadtime information or the operating frequency, whether the operating frequency deviates from a target operating frequency range. Based on the determination, one or both of the operating frequency or the input voltage are adjusted thereby causing the operating frequency to fall within the target operating frequency range.