With limited-power systems, the capacity of a power supply is limited and cannot be increased. Thus, power budget calculation is critical. However, the power budget calculation is not straight forward since included are estimates on power consumption for all radio circuits including unknown resistance of the supply cable, tolerances, margins, power pulses originated by radio network, and changes due to varying operating temperature. Consequently, discrepancies between power supply capacity, calculated power budget and actual power consumption can be substantially high leading to either design target failures or power supply overloading. In this work, a voltage-controlled current limiter controls maximum power consumption of a radio device. Both control voltage of the current limiter and radio power budget are set using resistance of the supply cable. Additionally, output voltage of the current limiter is used to adjust the radio power consumption. Hence, compared with published methods, the proposed method secures maximum power supply utilization while providing ultimate protection against the power supply overloading. Options for limited-power architectures are proposed.
