摘要 |
A power management circuit comprises an energy pump, a control circuit and a power consuming circuit. The power management circuit is connected in serial with a current loop in a serial connection with a field device to cause a regulated voltage drop across the serial connection at an insertion voltage and to output an electrical power derived from the insertion voltage. The energy pump inputs at least a portion of the insertion voltage, and a feedback sense, and output a charging voltage based on the feedback sense. The charging voltage sources the electrical power output by the power management circuit. The control circuit regulates the insertion voltage by modulating the feedback sense to the energy pump, and modulates the feedback sense in response to an electrical change in the current loop. The power consuming circuit receives the electrical power from the power management circuit. |