Unpowered switch and bleeder circuit

• US 7,619,462 B2
• Filed: 02/09/2006
• Issued: 11/17/2009
• Est. Priority Date: 02/09/2005
• Status: Active Grant

• Current Assignee: pSemi Corporation (Murata Manufacturing Co Limited)
• Original Assignee: Peregrine Semiconductor Corporation (Murata Manufacturing Co Limited)
• Inventors: Kelly, Dylan J., Kemerling, Clint L.
• Primary Examiner(s): Luu; An T
• Application Number:
  US11/351,342
• Publication Number:
  US 20060199563A1
• Time in Patent Office: 1,377 Days
• Field of Search: None
• US Class Current: 327/427
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence

Abstract

A novel RF switch for switching radio frequency (RF) signals is disclosed. The RF switch may comprise both enhancement and depletion mode field-effect transistors (E-FETs and D-FETs) implemented as a monolithic integrated circuit (IC) on a silicon-on-insulator (SOI) substrate. The disclosed RF switch, with a novel bleeder circuit, may be used in RF applications wherein a selected switch state and performance are required when the switch and bleeder circuits are not provided with operating power (i.e., when the switch and bleeder circuits are “unpowered”).

Claims

1. A monolithic integrated circuit (IC) RF switch comprising a plurality of MixedMode RF switches coupled together in a cascaded series-shunt configuration such that the output of a preceding MixedMode RF switch is coupled to the input of an immediately subsequent MixedMode RF switch, an input of the cascaded series-shunt configuration being the input of a first one of the cascaded MixedMode RF switches and an output of the cascaded series-shunt configuration being the output of a last one of the MixedMode RF switches, wherein a MixedMode RF switch is defined as one of the following RF switch types:

(a) a depletion-enhancement (D-E) RF switch comprising;

(1) a depletion-mode switch (D-Sw) circuit operatively coupled to receive a first RF signal from an RF input of the D-E RF switch and to selectively convey the first RF signal to an output of the D-E RF switch under control of a first control line C1; and

(2) an enhancement-mode shunt (E-Sh) circuit operatively coupled to receive the first RF signal and to selectively convey the first RF signal to ground under control of a second control line C1x; and

(b) an enhancement-depletion (E-D) RF switch comprising;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to receive a second RF signal from an input of the E-D RF switch and to selectively convey the second RF signal to an output of the E-D RF switch under control of a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to receive the second RF signal from the input of the E-D RF switch and to selectively convey the second RF signal to ground under control of a fourth control line C2x.

2. The IC RF switch of claim 1, wherein each MixedMode RF switch is a D-E RF switch.

3. The IC RF switch of claim 1, wherein each MixedMode RF switch is an E-D RF switch.

4. A monolithic integrated circuit (IC) RF switch comprising at least one RF switch selected from the following RF switch types:

(a) a depletion-enhancement (D-E) RF switch comprising;

(1) a depletion-mode switch (D-Sw) circuit operatively coupled to receive a first RF signal from an RF input of the D-E RF switch and to selectively convey the first RF signal to an output of the D-E RF switch under control of a first control line C1; and

(2) an enhancement-mode shunt (E-Sh) circuit operatively coupled to receive the first RF signal and to selectively convey the first RF signal to ground under control of a second control line C1x; and

(b) an enhancement-depletion (E-D) RF switch comprising;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to receive a second RF signal from an input of the E-D RF switch and to selectively convey the second RF signal to an output of the E-D RF switch under control of a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to receive the second RF signal from the input of the E-D RF switch and to selectively convey the second RF signal to ground under control of a fourth control line C2x;

wherein when the IC RF switch is not provided with operating power it operates in an UNPOWERED-STATE, and wherein when the IC RF switch is provided with operating power it operates in a POWERED-STATE, further comprising a bleeder circuit operatively coupled to ground and to one of the control lines C1, C1x, C2 and C2x, wherein the bleeder circuit has a first impedance between ground and said one of the control lines when the RF switch operates in the POWERED-STATE, and a second impedance between ground and said one of the control lines when the RF switch operates in the UNPOWERED-STATE, and the second impedance is less than the first impedance.

5. The IC RF switch of claim 4, wherein the bleeder circuit further comprises:

a) a first depletion-mode p-type transistor (DP1) having a first channel node operatively coupled to said one of the control lines;

b) a first depletion-mode n-type transistor having a first channel node operatively coupled to a second channel node of DP1 and a second channel node operatively coupled to ground;

c) a second depletion-mode p-type transistor (DP2) having a first channel node operatively coupled to a gate of DP1, a second channel node operatively coupled to a gate of DN1, and a gate operatively coupled to a bias supply voltage VDD;

d) a VDD voltage divider circuit operatively coupled to VDD, ground, the gate of DP1, and the first channel node of DP2 to convey a divided voltage level of VDD to the gate of DP1 and to the first channel node of DP2; and

e) a VSS voltage divider circuit operatively coupled to a bias supply voltage VSS, ground, the gate of DN1, and the second channel node of DP2 to convey a divided voltage level of VSS to the gate of DN1 and to the second channel node of DP2.

6. The IC RF switch of claim 5, wherein the bleeder circuit further comprises:

a) a third depletion-mode p-type transistor (DP3) interposed between the first channel node of DP1 and said one of the control lines, wherein the first channel node of DP1 is operatively coupled to a second channel node of DP3, a first channel node of DP3 is operatively coupled to said one of the control lines, and a gate of DP3 is operatively coupled to ground;

b) a second depletion-mode n-type transistor (DN2) interposed between the second node of DP1 and the first channel node of DN1, wherein a second channel node of DN2 is operatively coupled to the first channel node of DN1, and a first channel node of DN2 is operatively coupled to the second channel node of DP1, and a gate of DN2 is operatively coupled to ground; and

c) a fourth depletion-mode p-type transistor (DP4) interposed between the second channel node of DP2 and both the gate of DN1 and the VSS voltage divider circuit, wherein a first channel node of DP4 is operatively coupled to the second channel node of DP2, a second channel node of the DP4 is operatively coupled to the gate of DN1, and a gate of DP4 is operatively coupled to receive the divided voltage level of VDD.

7. The IC RF switch of claim 6, wherein the bleeder circuit further comprises:

a) a fifth depletion-mode p-type transistor (DP5), wherein a first channel node of DP5 is operatively coupled to VSS, and wherein a second channel node of DP5 is operatively coupled to ground, and wherein a gate of DP5 is operatively coupled to the VDD voltage divider circuit to receive the divided voltage level of VDD; and

b) a capacitor, wherein a first node of the capacitor is operatively coupled to the first channel node of DP5 and to VSS, and wherein a second node of the capacitor is operatively coupled to ground.

8. A monolithic integrated circuit (IC) RF switch comprising at least one RF switch selected from the following RF switch types:

(a) a depletion-enhancement (D-E) RF switch comprising;

(1) a depletion-mode switch (D-Sw) circuit operatively coupled to receive a first RF signal from an RF input of the D-E RF switch and to selectively convey the first RF signal to an output of the D-E RF switch under control of a first control line C1; and

(2) an enhancement-mode shunt (E-Sh) circuit operatively coupled to receive the first RF signal and to selectively convey the first RF signal to ground under control of a second control line C1x; and

(b) an enhancement-depletion (E-D) RF switch comprising;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to receive a second RF signal from an input of the E-D RF switch and to selectively convey the second RF signal to an output of the E-D RF switch under control of a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to receive the second RF signal from the input of the E-D RF switch and to selectively convey the second RF signal to ground under control of a fourth control line C2x;

wherein at least one of the D-Sw circuit, E-Sh circuit, E-Sw circuit, and D-Sh circuit components comprises a plurality of transistors coupled together in a stacked configuration such that channels of the plurality of transistors are coupled in series.

9. The IC RF switch of claim 8, wherein the plurality of transistors are configured in a symmetrically stacked configuration.

10. The IC RF switch of claim 8, wherein the plurality of transistors are configured in an asymmetrically stacked configuration.

11. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch, comprising:

(a) a first RF switch for selectively conveying a first RF signal between a first RF input node and an RF common node (RFcommon), the first RF switch including a D-E RF switch that has;

(1) a depletion-mode switch (D-Sw) circuit controlled by a first control line C1 and operatively coupled to selectively convey the first RF signal to RFcommon; and

(2) an enhancement-mode shunt (E-Sh) circuit controlled by a second control line C1x and operatively coupled to selectively convey the first RF signal to ground; and

(b) a second RF switch for selectively conveying a second RF signal between a second RF input node and RFcommon, the second RF switch including an E-D RF switch that has;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to convey the second RF signal to RFcommon under control of a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to convey the second RF signal to ground under control of a fourth control line C2x;

wherein the first RF switch or the second RF switch includes a plurality of RF switches cascaded in series between the corresponding input node and RFcommon.

12. The SPDT RF switch of claim 11, further comprising a plurality of cascaded D-E RF switches configured to selectively convey the first RF signal between the first RF input node and RFcommon.

13. The SPDT RF switch of claim 11, further comprising a plurality of cascaded E-D RF switches configured to selectively convey the second RF signal between the second RF input node and RFcommon.

14. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch. comprising:

(a) a D-E RF switch for selectively conveying a first RF signal between a first RF input node and an RF common node (RFcommon), including;

(1) a depletion-mode switch (D-Sw) circuit controlled by a first control line C1 and operatively coupled to selectively convey the first RF signal to RFcommon; and

(2) an enhancement-mode shunt (E-Sh) circuit controlled by a second control line C1x and operatively coupled to selectively convey the first RF signal to ground; and

(b) an E-D RF switch for selectively conveying a second RF signal between a second RF input node and RFcommon, including;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to convey the second RF signal to RFcommon under control of a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to convey the second RF signal to ground under control of a fourth control line C2x;

wherein when the switch is not provided with operating power it operates in an UNPOWERED-STATE, and wherein when the switch is provided with operating power it operates in a POWERED-STATE, further comprising a bleeder circuit operatively coupled to ground and to one of the control lines, wherein the bleeder circuit has a first impedance between ground and said one of the control lines when the RF switch operates in the POWERED-STATE, and wherein the bleeder circuit has a second impedance between ground and said one of the control lines when the RF switch operates in the UNPOWERED-STATE, and wherein the second impedance is less than the first impedance.

15. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch, comprising:

(a) a D-E RF switch for selectively conveying a first RF signal between a first RF input node and an RF common node (RFcommon), including;

(1) a depletion-mode switch (D-Sw) circuit controlled by a first control line C1 and operatively coupled to selectively convey the first RF signal to RFcommon; and

(2) an enhancement-mode shunt (E-Sh) circuit controlled by a second control line C1x and operatively coupled to selectively convey the first RF signal to ground; and

(b) an E-D RF switch for selectively conveying a second RF signal between a second RF input node and RFcommon, including;

(1) an enhancement-mode switch (E-Sw) circuit operatively coupled to convey the second RF signal to RFcommon under control of a third control line C2; and

(2) a depletion-mode shunt (D-Sh) circuit operatively coupled to convey the second RF signal to ground under control of a fourth control line C2x;

wherein at least one of the D-Sw circuit, E-Sh circuit, E-Sw circuit, and D-Sh circuit components comprises a plurality of transistors coupled together in a stacked configuration such that channels of the plurality of transistors are coupled in series.

16. The SPDT RF switch of claim 15, wherein the plurality of transistors are configured in a symmetrically stacked configuration.

17. The SPDT RF switch of claim 15, wherein the plurality of transistors are configured in an asymmetrically stacked configuration.

18. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch, comprising:

(a) a first E-D RF switch configured to selectively convey a first RF signal between a first RF input node and an RF common node (RFcommon), including;

(1) a first enhancement-mode switch (E-Sw) circuit operatively coupled to selectively convey the first RF signal to the RFcommon under control of a first control line C1; and

(2) a first depletion-mode shunt (D-Sh) circuit operatively coupled to selectively convey the first RF signal to ground under control of a second control line C1x; and

(b) a second E-D RF switch configured to selectively convey a second RF signal between a second RF input node and RFcommon, including;

(1) a second enhancement-mode switch (E-Sw) circuit operatively coupled to selectively convey the second RF signal to RFcommon under control of a third control line C2; and

(2) a second depletion-mode shunt (D-Sh) circuit operatively coupled to selectively convey the second RF signal to ground under control of a fourth control line C2x;

wherein when the switch is not provided with operating power it operates in an UNPOWERED-STATE and when the switch is provided with operating power it operates in a POWERED-STATE, further comprising a bleeder circuit operatively coupled to ground and to at least one of the control lines, wherein the bleeder circuit has a first impedance between ground and said one of the control lines when the RF switch operates in the POWERED-STATE and a second impedance between ground and said one of the control lines when the RF switch operates in the UNPOWERED-STATE, and the second impedance is less than the first impedance.

19. The SPDT RF switch of claim 18, wherein at least one of the E-D RF switches comprises a plurality of E-D RF switches coupled together in a cascaded series-shunt configuration such that the output of each preceding E-D RF switch is coupled to the input of an immediately subsequent E-D RF switch, an input of the cascaded series-shunt configuration being the input of a first E-D RF switch and an output of the cascaded series-shunt configuration being the output of a last E-D RF switch.

20. A monolithic integrated circuit single-pole double-throw (SPDT) RF switch, comprising:

(a) a first E-D RF switch configured to selectively convey a first RF signal between a first RF input node and an RF common node (RFcommon), including;

(1) a first enhancement-mode switch (E-Sw) circuit operatively coupled to selectively convey the first RF signal to the RFcommon under control of a first control line C1; and

(2) a first depletion-mode shunt (D-Sh) circuit operatively coupled to selectively convey the first RF signal to ground under control of a second control line C1x; and

(b) a second E-D RF switch configured to selectively convey a second RF signal between a second RF input node and RFcommon, including;

(1) a second enhancement-mode switch (E-Sw) circuit operatively coupled to selectively convey the second RF signal to RFcommon under control of a third control line C2; and

(2) a second depletion-mode shunt (D-Sh) circuit operatively coupled to selectively convey the second RF signal to ground under control of a fourth control line C2x;

wherein at least one of the first E-Sw circuit, the first D-Sh circuit, the second E-Sw circuit and the second D-Sh circuit comprises a plurality of transistors coupled together in a stacked configuration such that channels of the plurality of transistors are coupled in series.

21. The SPDT RF switch of claim 20, wherein the plurality of transistors are configured in a symmetrically stacked configuration.

22. The SPDT RF switch of claim 20, wherein the plurality of transistors are configured in an asymmetrically stacked configuration.