Radio frequency switch controller

Patent metadata

Field	Value
Publication number	US-9391648-B2
Application number	US-201514732477-A
Country	US
Kind code	B2
Filing date	Jun 5, 2015
Priority date	Aug 30, 2011
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

Implementations of radio frequency switch controllers within the scope of the appended claims are configured to reduce the impact of the clock signal induced spurs. In particular, implementations of switch controllers described herein include a poly-phase clocking scheme, as opposed to a single phase to clock the charge pump stages of an negative voltage generator. In some implementations poly-phase clocking schemes reduce the clock signal induced spurs and may preclude the need for additional on-chip or off-chip decoupling capacitors that add to the cost and physical size of a complete front end module solution.

First claim

What is claimed is:

1. A switch controller comprising:
a negative voltage generator including at least two sub-circuits configured to receive at least two control signals, each sub-circuit configured to receive a respective control signal of the at least two control signals and to draw from a regulated supply in response to an edge of the respective control signal, the negative voltage generator including one or more outputs configured to generate one or more negative voltages;
a control signal generator configured to provide the at least two control signals to the negative voltage generator such that the at least two control signals are separated by at least one non-zero phase difference;
a filter electrically connected to the one or more outputs of the negative voltage generator and configured to filter the one or more negative voltages; and
a level-shifter array configured to receive the one or more negative voltages and the regulated supply.

2. The switch controller of claim 1 wherein the at least one non-zero phase difference is selected to increase the frequency of an electrical spur induced by feed-through of at least one of the at least two control signals of the control signal generator.

3. The switch controller of claim 2 wherein a frequency of the electrical spur is increased beyond a natural frequency roll-off of a system including the switch controller.

4. The switch controller of claim 2 wherein a magnitude of the electrical spur is reduced at least in part as a function of a number of different phases of the at least two control signals received by the negative voltage generator.

5. The switch controller of claim 1 further comprising a dither generator configured to dither one or more of the at least two control signals provided by the control signal generator.

6. The switch controller of claim 1 wherein the at least two sub-circuits include at least two charge pumps.

7. The switch controller of claim 6 wherein the at least two charge pumps are electrically connected in series with one another.

8. The switch controller of claim 1 wherein the control signal generator includes a poly-phase oscillator configured to generate each of the at least two control signals with different phases.

9. The switch controller of claim 1 further comprising a voltage regulator configured to generate the regulated supply.

10. A method of negative voltage generation, the method comprising:
generating a plurality of clock signals of different phases using a clock source, the plurality of clock signals including a first clock signal and a second clock signal separated by a non-zero phase difference;
providing the plurality of clocks signals to a negative voltage generator that includes a plurality of charge pumps including a first charge pump and a second charge pump;
generating one or more negative voltages at one or more outputs of the negative voltage generator;
drawing from a regulated supply in response to an edge of the first clock signal using the first charge pump;
drawing from the regulated supply in response to an edge of the second clock signal using the second charge pump;
filtering the one or more negative voltages generated at the one or more outputs of the negative voltage generator using a filter; and
providing the one or more negative voltages and the regulated supply to a level shifter array.

11. The method of claim 10 further comprising dithering one or more of the plurality of clock signals using a dither generator.

12. A switch controller for a radio frequency system, the switch controller comprising:
a clock source configured to generate a plurality of clock signals including a first clock signal and a second clock signal, the first clock signal and the second clock signal having a non-zero phase difference;
a negative voltage generator including a plurality of charge pumps including a first charge pump and a second charge pump, the first charge pump configured to receive the first clock signal and to draw from a regulated supply in response to an edge of the first clock signal, the second charge pump configured to receive the second clock signal and to draw from the regulated supply in response to an edge of the second clock signal, the negative voltage generator including one or more outputs configured to generate one or more negative voltages;
a filter electrically connected to the one or more outputs of the negative voltage generator and configured to filter the one or more negative voltages; and
a level shifter array configured to receive the one or more negative voltages and the regulated supply.

13. The switch controller of claim 12 further comprising a dither generator configured to dither one or more of the plurality of clock signals.

14. The switch controller of claim 12 wherein the clock source includes a poly-phase oscillator.

15. The switch controller of claim 12 further comprising a voltage regulator configured to generate the regulated supply.

16. The switch controller of claim 12 wherein the first charge pump and the second charge pump are electrically connected in series with one another.

17. The switch controller of claim 1 wherein the filter includes a low pass filter that decreases a magnitude of an electrical spur induced by feed-through of at least one of the at least two control signals of the control signal generator.

18. The method of claim 10 further comprising controlling a radio frequency switch using the level shifter array.

19. The method of claim 10 further comprising generating the plurality of clock signals of different phases using a poly-phase oscillator.

20. The method of claim 10 further comprising generating the regulated supply using a voltage regulator.

Assignees

• Skyworks Solutions Inc

Inventors

• Popplewell Peter Harris Robert
• Pingot Jakub F
• Balteanu Florinel G

Classifications

• H04B1/44

  Transmit/receive switching · CPC title

• H02M3/073

  Charge pumps of the Schenkel-type · CPC title

• H02M3/07

  using capacitors charged and discharged alternately by semiconductor devices with control electrode {, e.g. charge pumps} · CPC title

• H04B15/06 Primary

  by local oscillators of receivers · CPC title

• H04B1/006 Primary

  using switches for selecting the desired band (H04B1/0057 takes precedence) · CPC title