The MLS modulation system 1050 of FIG. 9 illustrates one implementation of MLS modulator circuitry suitable for incorporation in a multi-level envelope tracker. However, other implementations of MLS modulator circuitry can be included in multi-level envelope trackers implemented in accordance with the teachings herein.

The MLS DC-to-DC converter 1025 generates a first regulated voltage V_MLS1, a second regulated voltage V_MLS2, and a third regulated voltage V_MLS3 based on providing DC-to-DC conversion of a battery voltage V_BATT. Although an example with three regulated voltages is shown, the MLS DC-to-DC converter 1025 can generate more or fewer regulated voltages. In certain implementations, at least a portion of the regulated voltages are boosted relative to the battery voltage V_BATT. Additionally or alternatively, one or more of the regulated voltages is a buck voltage having a voltage lower than the battery voltage V_BATT.

The decoupling capacitor bank 1030 aids in stabilizing the regulated voltages generated by the MLS DC-to-DC converter 1025. For example, the decoupling capacitor bank 1030 of FIG. 9 includes a first decoupling capacitor 1031 for decoupling the first regulated voltage V_MLS1, a second decoupling capacitor 1032 for decoupling the second regulated voltage V_MLS2, and a third decoupling capacitor 1033 for decoupling the third regulated voltage V_MLS3.