Multi-voltage generation circuit
A multi-voltage power generation circuit is disclosed. More specifically, the multi-voltage generation circuit includes multiple voltage modulation circuits that are configured to generate and maintain multiple modulated voltages. In a non-limiting example, the multiple modulated voltages can be used for amplifying multiple radio frequency (RF) signals concurrently. Contrary to using multiple direct-current (DC) to DC (DC-DC) converters for generating the multiple modulated voltages, the voltage modulation circuits are configured to share a single current modulation circuit based on time-division. By sharing a single current modulation circuit among the multiple voltage modulation circuits, it is possible to concurrently support multiple load circuits (e.g., power amplifier circuits) with significantly reduced footprint.
1 . A multi-voltage generation circuit comprising:
a current modulation circuit configured to generate a plurality of low-frequency currents;
a plurality of voltage modulation circuits configured to share the current modulation circuit based on a time-division schedule and each comprising:
a respective one of a plurality of voltage amplifiers configured to generate a respective one of a plurality of modulated initial voltages based on a respective one of a plurality of modulated target voltages; and
a respective one of a plurality of offset capacitors each modulated to a respective one of a plurality of offset voltages by a respective one of the plurality of low-frequency currents such that the respective one of the plurality of offset voltages can raise the respective one of the plurality of modulated initial voltages to thereby generate a respective one of a plurality of modulated voltages; and
a control circuit configured to:
determine the time-division schedule comprising an order of a plurality of non-overlapping charge intervals for generating the plurality of low-frequency currents, respectively, in one or more operation periods; and
cause the current modulation circuit to generate a respective one of the plurality of low-frequency currents in a respective one of the plurality of non-overlapping charge intervals in each of the one or more operation periods according to the determined order.
2 . The multi-voltage generation circuit of claim 1 , wherein the control circuit is further configured to determine the order of the plurality of non-overlapping charge intervals to minimize a relative change in any of the plurality of low-frequency currents between each adjacent pair of the plurality of non-overlapping charge intervals.
3 . The multi-voltage generation circuit of claim 1 , wherein the current modulation circuit comprises:
a multi-level charge pump (MCP) configured to operate based on a plurality of duty cycles to generate a plurality of low-frequency voltages each as a function of a battery voltage; and
a power inductor coupled between the MCP and a common node and configured to induce the plurality of low-frequency currents based on the plurality of low-frequency voltages, respectively;
wherein the control circuit is further configured to determine the plurality of duty cycles in accordance with the determined order for generating the plurality of low-frequency currents to thereby cause the current modulation circuit to generate the plurality of low-frequency currents in each of the one or more operation periods.
4 . The multi-voltage generation circuit of claim 3 , wherein the control circuit is further configured to cause each of the plurality of offset capacitors to be charged to the respective one of the plurality of offset voltages during a respective one of the plurality of non-overlapping charge intervals.
5 . The multi-voltage generation circuit of claim 4 , wherein the control circuit is further configured to:
determine a plurality of discharge intervals in each of the one or more operation periods each non-overlapping with the respective one of the plurality of charge intervals; and
cause each of the plurality of offset capacitors to be discharged to maintain the respective one of the plurality of modulated voltages during a respective one of the plurality of discharge intervals.
6 . The multi-voltage generation circuit of claim 5 , wherein each of the plurality of voltage modulation circuits further comprises:
a respective voltage output that outputs the respective one of the plurality of modulated voltages, wherein the respective one of the plurality of offset capacitors is coupled between a respective one of the respective one of the plurality of voltage amplifiers and the respective voltage output;
a respective bypass switch coupled between the respective output of the respective one of the plurality of voltage amplifiers and a ground; and
a respective on-off switch coupled between the power inductor and the respective voltage output.
7 . The multi-voltage generation circuit of claim 6 , wherein the control circuit is further configured to, for each of the plurality of voltage modulation circuits:
close the respective on-off switch during the respective one of the plurality of non-overlapping charge intervals to provide a respective one of the plurality of low-frequency currents from the common node to the respective voltage output;
close the respective bypass switch during the respective one of the plurality of non-overlapping charge intervals such that the respective one of the plurality of low-frequency currents can charge the respective one of the plurality of offset capacitors to the respective one of the plurality of offset voltages; and
cause the respective one of the plurality of voltage amplifiers to source or sink a respective high-frequency current during the respective one of the plurality of non-overlapping charge intervals to thereby maintain the respective one of the plurality of modulated voltages.
8 . The multi-voltage generation circuit of claim 7 , wherein the control circuit is further configured to, for each of the plurality of voltage modulation circuits:
open the respective on-off switch during the respective one of the plurality of discharge intervals to block the respective one of the plurality of low-frequency currents from flowing from the common node to the respective voltage output; and
open the respective bypass switch during the respective one of the plurality of discharge intervals such that the respective one of the plurality of offset capacitors is discharged to maintain the respective one of the plurality of modulated voltages.
9 . The multi-voltage generation circuit of claim 7 , wherein each of the plurality of voltage amplifiers is further configured to generate a respective one of a plurality of sense currents indicating a respective amount of the high-frequency current that is sourced/sunk by the respective one of the plurality of voltage amplifiers during the respective one of the plurality of non-overlapping charge intervals.
10 . The multi-voltage generation circuit of claim 9 , wherein the control circuit is further configured to determine each of the plurality of duty cycles based on one or more of:
the respective one of the plurality of modulated initial voltages;
the respective one of the plurality of offset voltages;
the respective one of the plurality of modulated voltages; and
the respective one of the plurality of sense currents.
11 . A method for generating multiple low-frequency currents comprising:
determining a time-division schedule comprising an order of a plurality of non-overlapping charge intervals for generating a plurality of low-frequency currents, respectively, in one or more operation periods;
generating a respective one of the plurality of low-frequency currents in a respective one of the plurality of non-overlapping charge intervals in each of the one or more operation periods according to the determined order in the time-division schedule;
generating a respective one of a plurality of modulated initial voltages based on a respective one of a plurality of modulated target voltages; and
modulating a respective one of a plurality of offset voltages by a respective one of the plurality of low-frequency currents such that the respective one of the plurality of offset voltages can raise the respective one of the plurality of modulated initial voltages to thereby generate a respective one of a plurality of modulated voltages.
12 . The method of claim 11 , further comprising determining the order of the plurality of non-overlapping charge intervals to minimize a relative change in any of the plurality of low-frequency currents between each adjacent pair of the plurality of non-overlapping charge intervals.
13 . The method of claim 11 , further comprising:
operating based on a plurality of duty cycles to generate a plurality of low-frequency voltages each as a function of a battery voltage;
inducing the plurality of low-frequency currents based on the plurality of low-frequency voltages, respectively; and
determining the plurality of duty cycles in accordance with the determined current generation in order to thereby generate the plurality of low-frequency currents in each of the one or more operation periods.
14 . The method of claim 13 , further comprising charging a plurality of offset capacitors in the plurality of non-overlapping charge intervals based on the plurality of low-frequency currents, respectively.
15 . The method of claim 14 , further comprising:
determining a plurality of discharge intervals in each of the one or more operation periods each non-overlapping with the respective one of the plurality of charge intervals; and
discharging the plurality of offset capacitors in the plurality of discharge intervals, respectively.
16 . A multi-voltage power management circuit comprising:
a plurality of power amplifier circuits configured to concurrently amplify a plurality of radio frequency (RF) signals based on a plurality of modulated voltages, respectively; and
a multi-voltage generation circuit comprising:
a current modulation circuit configured to generate a plurality of low-frequency currents;
a plurality of voltage modulation circuits configured to share the current modulation circuit based on a time-division schedule and each comprising:
a respective one of a plurality of voltage amplifiers configured to generate a respective one of a plurality of modulated initial voltages based on a respective one of a plurality of modulated target voltages; and
a respective one of a plurality of offset capacitors each modulated to a respective one of a plurality of offset voltages by a respective one of the plurality of low-frequency currents such that the respective one of the plurality of offset voltages can raise the respective one of the plurality of modulated initial voltages to thereby generate a respective one of the plurality of modulated voltages; and
a control circuit configured to:
determine the time-division schedule comprising an order of a plurality of non-overlapping charge intervals for generating the plurality of low-frequency currents, respectively, in one or more operation periods; and
cause the current modulation circuit to generate a respective one of the plurality of low-frequency currents in a respective one of the plurality of non-overlapping charge intervals in each of the one or more operation periods according to the determined order.
17 . The multi-voltage power management circuit of claim 16 , wherein the control circuit is further configured to determine the order of the plurality of non-overlapping charge intervals to minimize a relative change in any of the plurality of low-frequency currents between each adjacent pair of the plurality of non-overlapping charge intervals.
18 . The multi-voltage power management circuit of claim 16 , wherein the current modulation circuit comprises:
a multi-level charge pump (MCP) configured to operate based on a plurality of duty cycles to generate a plurality of low-frequency voltages each as a function of a battery voltage; and
a power inductor coupled between the MCP and a common node and configured to induce the plurality of low-frequency currents based on the plurality of low-frequency voltages, respectively;
wherein the control circuit is further configured to determine the plurality of duty cycles in accordance with the determined order for generating the plurality of low-frequency currents to thereby cause the current modulation circuit to generate the plurality of low-frequency currents in each of the one or more operation periods.
19 . The multi-voltage power management circuit of claim 18 , wherein the control circuit is further configured to cause each of the plurality of offset capacitors to be charged to the respective one of the plurality of offset voltages during a respective one of the plurality of non-overlapping charge intervals.
20 . The multi-voltage power management circuit of claim 19 , wherein the control circuit is further configured to:
determine a plurality of discharge intervals in each of the one or more operation periods each non-overlapping with the respective one of the plurality of charge intervals; and
cause each of the plurality of offset capacitors to be discharged to maintain the respective one of the plurality of modulated voltages during a respective one of the plurality of discharge intervals.