Power management apparatus operable with multiple configurations
A power management apparatus operable with multiple configurations is disclosed. In embodiments disclosed herein, the power management apparatus can be configured to concurrently generate multiple modulated voltages based on a configuration including a single power management integrated circuit (PMIC) or a configuration including a PMIC and a distributed PMIC. Regardless of the configuration, the power management apparatus employs a single switcher circuit, wherein multiple reference voltage circuits are configured to share a multi-level charge pump (MCP). As a result, it is possible to reduce footprint of the power management apparatus while improving isolation between the multiple modulated voltages.
1. A power management apparatus comprising:
a switcher circuit comprising:
a multi-level charge pump (MCP) configured to operate based on a duty cycle to generate a low-frequency voltage as a function of a battery voltage;
a first reference voltage circuit configured to generate a first reference voltage based on the low-frequency voltage; and
a second reference voltage circuit configured to generate a second reference voltage based on the low-frequency voltage;
a control circuit configured to determine the duty cycle based on a selected one of a first target voltage and a second target voltage;
a first voltage circuit coupled to the first reference voltage circuit and configured to generate a first modulated voltage comprising a first initial modulated voltage generated based on the first target voltage and a first offset voltage modulated based on the first reference voltage; and
a second voltage circuit coupled to the second reference voltage circuit and configured to generate a second modulated voltage comprising a second initial modulated voltage generated based on the second target voltage and a second offset voltage modulated based on the second reference voltage.
2. The power management apparatus of claim 1 , wherein the first reference voltage circuit and the second reference voltage circuit are each configured to generate a respective one of the first reference voltage and the second reference voltage as an average of the low-frequency voltage.
3. The power management apparatus of claim 2 , wherein each of the first reference voltage circuit and the second reference voltage circuit is an inductor-capacitor (LC) circuit configured to resonate at a respective resonance frequency to generate the respective one of the first reference voltage and the second reference voltage as the average of the low-frequency voltage.
4. The power management apparatus of claim 2 , wherein the first reference voltage is substantially equal to the second reference voltage.
5. The power management apparatus of claim 1 , wherein:
the first voltage circuit comprises:
a first voltage amplifier configured to generate the first initial modulated voltage based on the first target voltage;
a first offset capacitor configured to raise the first initial modulated voltage by the first offset voltage to generate the first modulated voltage; and
a first hybrid circuit configured to modulate the first offset voltage based on the first reference voltage; and
the second reference voltage circuit comprises:
a second voltage amplifier configured to generate the second initial modulated voltage based on the second target voltage;
a second offset capacitor configured to raise the second initial modulated voltage by the second offset voltage to generate the second modulated voltage; and
a second hybrid circuit configured to modulate the second offset voltage based on the second reference voltage.
6. The power management apparatus of claim 5 , wherein the first hybrid circuit and the second hybrid circuit are each configured to:
operate in a switch mode to cause a respective one of the first offset voltage and the second offset voltage to be equal to a respective one of the first reference voltage and the second reference voltage; and
operate in a low dropout (LDO) mode to cause the respective one of the first offset voltage and the second offset voltage to be lower than the respective one of the first reference voltage and the second reference voltage.
7. The power management apparatus of claim 6 , wherein the control circuit is further configured to determine the selected one of the first target voltage and the second target voltage as any one of the first target voltage and the second target voltage having a higher root-mean-square (RMS) level.
8. The power management apparatus of claim 7 , wherein the control circuit is further configured to:
determine that the first target voltage has the higher RMS level than the second target voltage;
cause the MCP to generate the low-frequency voltage based on the first target voltage;
cause the first hybrid circuit to operate in the switch mode; and
cause the second hybrid circuit to operate in the LDO mode.
9. The power management apparatus of claim 7 , wherein the control circuit is further configured to:
determine that the second target voltage has the higher RMS level than the first target voltage;
cause the MCP to generate the low-frequency voltage based on the second target voltage;
cause the first hybrid circuit to operate in the LDO mode; and
cause the second hybrid circuit to operate in the switch mode.
10. The power management apparatus of claim 7 , wherein the control circuit is further configured to:
determine that the first target voltage and the second target voltage have an equal RMS level;
cause the MCP to generate the low-frequency voltage based on any of the first target voltage and the second target voltage;
cause the first hybrid circuit to operate in the switch mode; and
cause the second hybrid circuit to operate in the switch mode.
11. The power management apparatus of claim 1 , further comprising a power management integrated circuit (PMIC).
12. The power management apparatus of claim 11 , wherein the PMIC comprises the first voltage circuit, the second reference voltage circuit, the switcher circuit, and the control circuit.
13. The power management apparatus of claim 11 , wherein the PMIC comprises the first voltage circuit, the switcher circuit, and the control circuit.
14. The power management apparatus of claim 13 , further comprising a distributed PMIC separated from the PMIC and comprising the second reference voltage circuit.
15. A wireless device comprising a power management apparatus, the power management apparatus comprises:
a switcher circuit comprising:
a multi-level charge pump (MCP) configured to operate based on a duty cycle to generate a low-frequency voltage as a function of a battery voltage;
a first reference voltage circuit configured to generate a first reference voltage based on the low-frequency voltage; and
a second reference voltage circuit configured to generate a second reference voltage based on the low-frequency voltage;
a control circuit configured to determine the duty cycle based on a selected one of a first target voltage and a second target voltage;
a first voltage circuit coupled to the first reference voltage circuit and configured to generate a first modulated voltage comprising a first initial modulated voltage generated based on the first target voltage and a first offset voltage modulated based on the first reference voltage; and
a second voltage circuit coupled to the second reference voltage circuit and configured to generate a second modulated voltage comprising a second initial modulated voltage generated based on the second target voltage and a second offset voltage modulated based on the second reference voltage.