| 摘要 |
A multi-mode, dynamic, DC-DC converter supplies a dynamically varying voltage, as required, from a battery to an RF power amplifier (PA). In envelope tracking mode, a fast DC- DC converter generates a dynamic voltage that varies based on the amplitude envelope of an RF signal, and regulates the voltage at the PA. A slow DC-DC converter generates a steady voltage and regulates the voltage across a link capacitor. The fast and slow converters are in parallel from the view of the PA, and the link capacitor is between the fast converter and the PA. Because different nodes are regulated, no current sharing is possible between the converters. The link capacitor boosts the dynamic voltage level, allowing a maximum dynamic voltage at the load to exceed the battery voltage. In power level tracking mode, the fast converter is disabled and the link capacitor is configured to be in parallel with the load. The slow converter directly regulates the PA, and the link capacitor is in parallel with (added to) an output capacitor. Multiple wireless network standards may be supported, allowing for the sharing of RF circuits. |
