Embodiments of an analog-to-digital converter (ADC) and methods for controlling RF power levels are generally described herein. Other embodiments may be described and claimed. In some embodiments, the ADC includes an internal-reference digital-to-analog converter (DAC) having a resistive structure with linearly-spaced contact nodes. The linearly-spaced contact nodes may provide corresponding reference voltages that vary exponentially with respect to the linearly-spaced contact nodes allowing the ADC to achieve a logarithmic response.