| 摘要 |
A switching apparatus comprises a number of instantiations of switching load cells operating at a first voltage and at a second voltage to switch a digital structure. The instantiations are turned on by a respective control bits. Each load cell comprises a charging capacitor coupled to a power amplifier. An output node can be coupled to a load capacitance. Switching circuitry couples the charging capacitor to the load capacitance and connects a voltage regulator to the output node to regulate voltage to the second voltage. The timing logic couples the charging capacitor to the first voltage, couples the charging capacitor to the load capacitance and disconnects the first voltage from the charging capacitor during a switching event, disconnects the charging capacitor from the load capacitance and connects the voltage regulator to the output node after the switching event. The apparatus may be embodied in envelope tracking. |
