LOW LEAKAGE CURRENT SWITCH CONTROLLER

• US 20170300076A1
• Filed: 02/28/2017
• Published: 10/19/2017
• Est. Priority Date: 02/29/2016
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: LIANG, Bang Li, POPPLEWELL, Peter Harris Robert, BABCOCK, Gregory Edward
• Granted Patent: US 10,838,446 B2
• Time in Patent Office: Days
• CPC Class Codes: G05F 1/468 characterised by reference voltage circuitry, e.g. soft start, remote shutdown
• CPC Class Codes: G05F 1/595 semiconductor devices connected in series
• CPC Class Codes: H04B 1/44 Transmit/receive switching

Abstract

Low leakage current switch controller. In some embodiments, a controller for a radio-frequency switch can include a low-dropout regulator configured to generate a plurality of reference voltage levels for operation of a switch, or to be in a sleep mode to conserve power, based on a control signal received through a common input node. The controller can further include a mode detector in communication with the low-dropout regulator, and be configured to provide a first form of the control signal to the common input node to allow the plurality of reference levels to be generated by the low-dropout regulator, or a second form of the control signal to the common input node to put the low-dropout regulator in the sleep mode.

Claims

1. A controller for a radio-frequency switch, the controller comprising:

a low-dropout regulator configured to generate a plurality of reference voltage levels for operation of a switch, or to be in a sleep mode to conserve power, based on a control signal received through a common input node; and

a mode detector in communication with the low-dropout regulator, and configured to provide a first form of the control signal to the common input node to allow the plurality of reference levels to be generated by the low-dropout regulator, or a second form of the control signal to the common input node to put the low-dropout regulator in the sleep mode.

2. The controller of claim 1 wherein the low-dropout regulator is substantially free of a dedicated power down pin, separate from the common input node, for receiving a power down signal to put the low-dropout regulator into the sleep mode.

3. The controller of claim 1 wherein the common input node is connected to an enable pin, and the first form of the control signal is an enable signal.

4. The controller of claim 3 wherein the second form of the control signal is a disable signal that puts the low-dropout regulator in the sleep mode.

5. The controller of claim 1 wherein the mode selector is configured to be always alive when operation of the switch is possible.

6. The controller of claim 1 further comprising a low power bandgap circuit configured to provide a bandgap reference voltage to the low-dropout regulator.

7. The controller of claim 6 wherein the low power bandgap circuit is configured to be always alive when operation of the switch is possible.

8. The controller of claim 6 wherein the low-dropout regulator includes an error amplifier configured to be controlled by the control signal from the mode detector, and to generate an output voltage Vout based on inputs including the bandgap reference voltage and a feedback voltage.

9. The controller of claim 8 wherein the low-dropout regulator further includes a first transistor having a gate controlled by the output voltage Vout from the error amplifier, and a source connected to a supply voltage.

10. The controller of claim 9 wherein the low-dropout regulator further includes a second transistor having a gate controlled by the control signal from the mode detector, and a source connected to a drain of the first transistor.

11. The controller of claim 10 wherein the low-dropout regulator further includes a plurality of source followers implemented in series with one end connected to a drain of the second transistor and the other end coupled to ground, such that a source of each of the source followers provides a respective reference voltage levels.

12. The controller of claim 11 wherein the low-dropout regulator further includes a resistor feedback network configured to provide input voltage levels for the source followers.

13. The controller of claim 11 wherein the resistor feedback network is configured to share a single DC current path to achieve a low leakage current.

14. The controller of claim 1 wherein the mode detector includes a logic circuit that includes a plurality of NOT gates each configured to receive an input logic signal and generate an output, an AND gate having a plurality of inputs coupled to the outputs of the NOT gates and an output, and a downstream NOT gate having an input coupled to the output of the AND gate and an output for providing the control signal.

15. The controller of claim 14 wherein the logic circuit is configured such that the first form of the control signal at the output of the downstream NOT gate has a high logic value when at least one of the input logic signals has a high logic value.

16. The controller of claim 14 wherein the logic circuit is configured such that the second form of the control signal at the output of the downstream NOT gate has a low logic value when each of the input logic signals has a low logic value.

17. The controller of claim 14 further comprising a level clipper configured to receive a plurality of input signals and provide level clipped signals as the input logic signals for the logic circuit.

18. (canceled)

19. (canceled)

20. A radio-frequency module comprising:

a packaging substrate configured to receive a plurality of components;

a switching circuit implemented on the packaging substrate; and

a control circuit implemented on the packaging substrate and configured to control operation of the switching circuit, the controller including a low-dropout regulator configured to generate a plurality of reference voltage levels for the operation of the switching circuit, or to be in a sleep mode to conserve power, based on a control signal received through a common input node, the controller further including a mode detector in communication with the low-dropout regulator, and configured to provide a first form of the control signal to the common input node to allow the plurality of reference levels to be generated by the low-dropout regulator, or a second form of the control signal to the common input node to put the low-dropout regulator in the sleep mode.

21. The radio-frequency module 20 wherein the switching circuit is implemented on a first semiconductor die and the controller is implemented on a second semiconductor die.

22. The radio-frequency module 20 wherein the switching circuit is implemented on a semiconductor die and the controller is also implemented on the same semiconductor die.

23. (canceled)

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)