AN RF SWITCH WITH INTER-DOMAIN ESD PROTECTION

• US 20140321008A1
• Filed: 04/26/2013
• Published: 10/30/2014
• Est. Priority Date: 04/26/2013
• Status: Active Grant

• Current Assignee: Ferfics Limited
• Original Assignee: Ferfics Limited
• Inventors: KEANE, JOHN, O'Sullivan, John, O'Regan, Ian
• Granted Patent: US 9,520,251 B2
• Time in Patent Office: Days
• US Class Current: 361/56
• CPC Class Codes: H01H 11/00 Apparatus or processes specially adapted for the manufacture of electric switches processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88
• CPC Class Codes: H02H 9/046 responsive to excess voltage appearing at terminals of integrated circuits protection by specific structural integration design H01L27/0248
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H03K 17/693 Switching arrangements with several input- or output-terminals, e.g. multiplexers, distributors logic circuits H03K19/00; code converters H03M5/00, H03M7/00

Abstract

An RF switch with inter-domain ESD protection. The RF switch comprises an RF domain section having a plurality of RF switching elements; and a DC domain section having circuitry configured for driving the RF switching elements. At least one primary ESD protection element is operably coupled between the RF domain section and DC domain section.

Claims

1. An RF switch with inter-domain ESD protection;

the RF switch comprising;

an RF domain section having a plurality of RF switching elements;

a DC domain section having circuitry configured for driving the RF switching elements; and

at least one primary ESD protection element operably coupled between the RF domain section and DC domain section.

2. An RF switch as claimed in claim 1, wherein the at least one primary ESD protection element is provided on a semiconductor substrate containing the RF domain section and the DC domain section.

3. An RF switch as claimed in claim 1, wherein the at least one primary ESD protection element is operably coupled between a supply voltage node in the DC domain section and an RF ground reference node in the RF domain section.

4. An RF switch as claimed in claim 3, wherein the RF domain section includes one or more RF ground reference nodes each associated with a corresponding transistor connecting two RF nodes.

5. An RF switch as claimed in claim 1, wherein the DC domain section comprises one or more secondary ESD protection elements.

6. An RF switch as claimed in claim 5, wherein the DC domain section comprises two secondary ESD protection elements.

7. An RF switch as claimed in claim 6, wherein one of the secondary ESD protection elements is operably coupled to an output node of a voltage regulator in the DC domain section.

8. An RF switch as claimed in claim 7, wherein the other one of the secondary ESD protection elements is operably coupled to an output node of a negative voltage generator in the DC domain section.

9. An RF switch as claimed in claim 1, further comprising a plurality of RF isolation filters operably coupled between the DC domain section and the RF domain section, the respective RF isolation filters include resistive loads which are scaled relatively to an effective resistive load that occurs between an output node of the RF isolation filter and a terminal of an RF switch element.

10. An RF switch as claimed in claim 1, further comprising at least one RF isolation filter having an ESD protection element, the at least one RF isolation filter being operably coupled between the DC domain section and the RF domain section.

11. An RF switch as claimed in claim 10, wherein the at least one RF isolation filter comprises a pair of capacitors and a resistor operably coupled there between, one of the capacitors is associated with the DC domain section and the other capacitor is associated with the RF domain section, the ESD protection element is operably coupled to the resistor.

12. An RF switch as claimed in claim 1, wherein the RF domain section comprises at least one stack of transistors, and a clamping element is associated with each transistor.

13. An RF switch as claimed in claim 12, wherein the clamping element is operably coupled between a body terminal and a gate terminal of the corresponding transistor.

14. An RF switch as claimed in claim 13, wherein the clamping element comprises a transistor.

15. An RF switch as claimed in claim 14, wherein the clamping element comprises a MOSFET transistor.

16. An RF switch as claimed in claim 13, wherein the clamping element is turned off during normal operation of the RF switch and is turned on in response to experiencing an ESD event.

17. A semiconductor substrate having an RF switch circuit with inter-domain ESD protection fabricated thereon, wherein the RF switch circuit comprises:

an RF domain section having a plurality of RF switching elements;

a DC domain section having circuitry configured for driving the RF switching elements; and

at least one primary ESD element operably coupled between the RF domain section and DC domain section.

18. A semiconductor substrate as claimed in claim 17 comprising a silicon-on-insulator arrangement.

19. A method of fabricating an RF switch circuit having inter-domain ESD protection;

the method comprises;

providing an RF domain section having a plurality of RF switching elements on a semiconductor substrate;

providing a DC domain section having circuitry configured for driving the RF switching elements on the semiconductor substrate; and

providing at least one primary ESD protection element operably coupled between the RF domain section and DC domain section on the semiconductor substrate.

20. A method as claimed in claim 19, wherein the at least one primary ESD protection element is operably coupled between a supply voltage node in the DC domain section and an RF ground reference node in the RF domain section.

21. A method as claimed in claim 19, further comprising:

providing one or more secondary ESD protection elements in the DC domain section.

22. A method as claimed in claim 21, further comprising:

coupling one of the secondary ESD protection elements to an output node of a voltage regulator in the DC domain section.

23. A method as claimed in claim 22, further comprising:

coupling a further secondary ESD protection elements to an output node of a negative voltage generator in the DC domain section.

24. A method as claimed in claim 19, further comprising coupling a plurality of RF isolation filters between the DC domain section and the RF domain section, the respective RF isolation filters include resistive loads which are scaled relatively to an effective resistive load that occurs between an output node of the RF isolation filter and a terminal of an RF switch element.

25. A method as claimed in claim 19, further comprising:

providing at least one RF isolation filter having an ESD protection element between the DC domain section and the RF domain section.

26. A method as claimed in claim 25, wherein the at least one RF isolation filter comprises a pair of capacitors and a resistor operably coupled there between, one of the capacitors is associated with the DC domain section and the other capacitor is associated with the RF domain section, the ESD protection element is operably coupled to the resistor.

27. A method as claimed in claim 19, further comprising:

providing at least one stack of transistors in the RF domain section, and

providing respective clamping elements on the semiconductor substrate which are associated with corresponding transistors.

28. A method as claimed in claim 27, further comprising:

coupling the respective clamping element between a body terminal and a gate terminal of the corresponding transistors.