DC-DC converter for envelope tracking
View Patent ↗Embodiments provide a DC-DC converter (DC-DC=direct current to direct current) for envelope tracking. The DC-DC converter includes a digital control stage and a driving stage. The digital control stage is configured to provide a digital control signal based on digital information describing an amplitude of a digital baseband transmit signal. The driving stage is configured to provide a supply voltage for an RF amplifier (RF=radio frequency) based on the digital control signal.
1. A DC-DC converter for envelope tracking, comprising:
a digital control stage comprising a digital modulator that is configured to generate a digital control signal in response to receiving digital information describing an amplitude of a digital baseband transmit signal and a digital value of a digital voltage reading from a battery voltage; and
a driving stage configured to provide a supply voltage for an RF amplifier based on the digital control signal.
2. The DC-DC converter according to claim 1 , wherein the digital modulator is further configured to generate a modulated digital control signal based on the digital information describing the amplitude of the digital baseband transmit signal.
3. The DC-DC converter according to claim 2 , wherein the digital modulator is configured to control a pulse width of the modulated digital control signal as a function of the digital information describing the amplitude of the digital baseband transmit signal.
4. The DC-DC converter according to claim 2 , wherein the digital modulator is configured to control a period of the modulated digital control signal as a function of the digital voltage reading of the battery voltage.
5. The DC-DC converter according to claim 2 , wherein the the digital modulator comprises a digital PWM that is configured to control a pulse width of the modulated digital control signal as a function of the digital information and control a modulation period of the modulated digital control signal as a function of the digital value of the digital voltage reading of the battery voltage.
6. The DC-DC converter according to claim 2 , wherein the digital control stage comprises a data item provider configured to generate one of a plurality of possible data items based on the digital information describing the amplitude of the digital baseband transmit signal;
wherein the digital modulator is configured to set a pulse width of the modulated digital control signal based on the one data item.
7. The DC-DC converter according to claim 6 , wherein the data item provider is further configured to generate the one data item based on the digital value of the digital voltage reading of the battery voltage;
wherein the digital modulator is configured to set a period of the modulated digital control signal based on the one data item.
8. The DC-DC converter according to claim 6 , wherein the data item provider is configured to select the one of the plurality of possible data items from a lookup table as a function of the digital information and the digital value of the digital voltage reading.
9. The DC-DC converter according to claim 1 , wherein the driving stage comprises an inverter configured to generate a first voltage in response to a first state of the digital control signal and to generate a second voltage in response to a second state of the digital control signal as the supply voltage for the RF amplifier.
10. The DC-DC converter according to claim 9 , wherein the first voltage comprises a supply voltage of a DC power supply and the second voltage comprises a reference voltage.
11. A DC-DC converter for envelope tracking, comprising:
a digital modulator configured to receive digital information that describes an amplitude of a digital baseband transmit signal from a transmitter and a digital value of a digital voltage reading from a DC power supply, and generate a modulated digital control signal as a function of the digital information and the digital value;
an inverter configured to provide a first voltage in response to a first state of the modulated digital control signal and to provide a second voltage in response to a second state of the modulated digital control signal as a supply voltage for an RF amplifier.
12. The DC-DC converter according to claim 11 , wherein the digital modulator is configured to set a pulse width of the modulated digital control signal based on the digital information describing the amplitude of the digital baseband transmit signal, and set a period of the modulated digital control signal based on the digital value.
13. The DC-DC converter according to claim 11 , wherein the DC-DC converter comprises an A/D converter configured to A/D convert an analog voltage reading of the DC power supply into the digital voltage reading of the DC power supply;
wherein the digital modulator is configured to set a period of the modulated digital control signal based on the digital value of the digital voltage reading of the DC power supply.
14. The DC-DC converter according to claim 11 , wherein the the digital modulator comprises a digital PWM configured to generate the modulated digital control signal that controls the supply voltage as a function of a pulse width from the digital information and the digital value.
15. The DC-DC converter according to claim 11 , wherein the digital modulator is further configured to obtain one of a plurality of possible data items from a lookup table in response to receiving the information describing the amplitude of the digital baseband transmit signal and the digital value of the digital voltage reading;
wherein the digital modulator is configured to set a pulse width of the modulated digital control signal based on the one of the plurality of possible data items.
16. The DC-DC converter according to claim 15 , wherein the DC-DC converter comprises an A/D converter configured to A/D convert an analog voltage reading of a DC power supply into a digital voltage reading of the DC power supply;
wherein the digital modulator is further configured to process the one data item from the lookup table in response to the digital voltage reading of the DC power supply and
to set a period of the modulated digital control signal based on the one data item.
17. The DC-DC converter according to claim 11 , wherein the first voltage is a supply voltage of a DC power supply and the second voltage is a reference voltage.
18. The DC-DC converter according to claim 11 , wherein the DC-DC converter comprises a low pass filter for low pass filtering the supply voltage for the RF amplifier.
19. A method for envelope tracking, comprising:
receiving, via a transmitter, digital information that indicates an amplitude of a digital baseband transmit signal of the transmitter and a digital value of a digital voltage reading from a power supply;
generating, via a digital modulator, a digital control signal based on the digital information and the digital value; and
providing a supply voltage for an RF amplifier based on the digital control signal.
20. A method for manufacturing a DC-DC converter for envelope tracking, comprising:
providing a digital control stage configured to generate a digital control signal from a digital information received from a digital transmitter that describes an amplitude of a digital baseband transmit signal of the digital transmitter and from a digital value received from a digital voltage reading of a battery voltage; and
providing a driving stage configured to generate a supply voltage for a RF amplifier based on the digital control signal.
21. The method according to claim 20 , wherein the digital control stage is provided on a silicon of a same chip as the digital transmitter.
22. The method according to claim 21 , wherein the driving stage is provided on the same chip as the digital transmitter.