Apparatus, system and method for providing switching with a T-coil circuit

Patent metadata

Field	Value
Publication number	US-9401706-B2
Application number	US-201414165340-A
Country	US
Kind code	B2
Filing date	Jan 27, 2014
Priority date	Jan 27, 2014
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

Techniques and mechanisms for switching between a plurality of inputs each to receive a respective analog signal to be transmitted. In an embodiment, switch circuitry comprises a first input to receive a first signal, a second input to receive a second signal, and one or more T-coil circuits including a first T-coil circuit. A first configuration of the switch circuitry includes a first signal path via a first switch coupled between the first input and a primary input node of the first T-coil circuit. A second configuration of the switch circuitry includes a second signal path via a second switch coupled between the second input and a secondary input node of the first T-coil circuit. In an embodiment, control logic transitions the switch circuitry among a plurality of configurations including the first configuration and the second configuration.

First claim

What is claimed is:

1. An apparatus comprising: a switch circuit including:
one or more T-coil circuits comprising a first T-coil circuit, each of the one or more T-coil circuits including:
a respective capacitor; and
two respective inductors coupled in series with each other via a secondary input node of the T-coil circuit, wherein the capacitor of the T-coil circuit is coupled in parallel with the two inductors of the T-coil circuit between a primary input node of the T-coil circuit and an output node of the T-coil circuit;

a first input to receive a first signal;
a first switch coupled between the first input and the primary input node of the first T-coil circuit, the first switch to switchedly configure a first signal path for the first signal;
a second input to receive a second signal; and
a second switch coupled between the second input and the secondary input node of the first T-coil circuit, the second switch to switchedly configure a second signal path for the second signal.

2. The apparatus of claim 1 , wherein the second switch to switchedly configure the second signal path for providing the second signal from the second switch directly to the secondary input node of the first T-coil circuit.

3. The apparatus of claim 2 , the switch circuit further comprising:
a third input to receive a third signal; and
a third switch coupled between the third input and the secondary input node of the first T-coil circuit, the third switch to switchedly configure a third signal path for providing the third signal from the third switch directly to the secondary input node of the first T-coil circuit.

4. The apparatus of claim 1 , the switch circuit further comprising:
a third input to receive a third signal;
a third switch coupled between the third input and the secondary input node of the first T-coil circuit, the third switch to switchedly configure a third signal path for the third signal; and
a fourth switch to switchedly configure a fourth signal path between the second switch and the secondary input node of the first T-coil circuit, wherein the fourth signal path is also between the third switch and the secondary input node of the first T-coil circuit.

5. The apparatus of claim 1 , the one or more T-coil circuits further comprising a second T-coil circuit, wherein the second switch is coupled between the second input and the primary input node of the second T-coil circuit, and wherein the output node of the second T-coil circuit is coupled to the secondary input node of the first T-coil circuit, the switch circuit further comprising:
a third input to receive a third signal; and
a third switch coupled between the third input and the second T-coil circuit, the third switch to switchedly configure a third signal path for the third signal.

6. The apparatus of claim 1 , the one or more T-coil circuits further comprising:
a second T-coil circuit, wherein the second switch is coupled between the second input and the primary input node of the second T-coil circuit, and wherein the output node of the second T-coil circuit is coupled to the secondary input node of the first T-coil circuit; and
a third T-coil circuit, wherein the output node of the third T-coil circuit is coupled to the secondary input node of the second T-coil circuit;

the switch circuit further comprising:
a third input to receive a third signal; and
a third switch coupled between the third input and the primary input node of the third T-coil circuit, the third switch to switchedly configure a third signal path for the third signal.

7. The apparatus of claim 1 , further comprising a plurality of transmit circuits each coupled to a respective input of the switch circuit, the plurality of transmit circuits including a first transmit circuit to provide the first signal to the first input and a second transmit circuit to provide the second signal to the second input.

8. The apparatus of claim 1 , further comprising control logic coupled to the switch circuit, the control logic to transition the switch circuit between a first configuration and a second configuration, including the control logic to change a switch state of one of the first switch and the second switch.

9. A method comprising: with switch circuitry:
during a first configuration of the switch circuitry:
receiving a first signal at a first input, wherein the switch circuitry includes one or more T-coil circuits comprising a first T-coil circuit, each of the one or more T-coil circuits including:
a respective capacitor; and
two respective inductors coupled in series with each other via a secondary input node of the T-coil circuit, wherein the capacitor of the T-coil circuit is coupled in parallel with the two inductors of the T-coil circuit between a primary input node of the T-coil circuit and an output node of the T-coil circuit; and

wherein the first configuration includes a first signal path via a first switch coupled between the first input and the primary input node of the first T-coil circuit;
providing at an output node of the switch circuitry a first output signal based on the first signal; and

during a second configuration of the switch circuitry:
receiving a second signal at a second input of the switch circuitry, wherein the second configuration includes a second signal path via a second switch coupled between the second input and the secondary input node of the first T-coil circuit; and
providing at the output node a second output signal based on the second signal.

10. The method of claim 9 , further comprising:
transitioning the switch circuit between a first configuration and a second configuration, including changing a switch state of one of the first switch and the second switch.

11. The method of claim 9 , further comprising:
during a third configuration of the switch circuitry:
receiving a third signal at a third input of the switch circuitry, wherein the third configuration includes a third signal path via a third switch coupled between the third input and the secondary input node of the first T-coil circuit; and
providing at the output node a third output signal based on the third signal.

12. The method of claim 11 , wherein the one or more T-coil circuits further comprise a second T-coil circuit, wherein the second switch is coupled between the second input and the primary input node of the second T-coil circuit, wherein the third switch is coupled between the third input and the secondary input node of the second T-coil circuit, and wherein the output node of the second T-coil circuit is coupled to the secondary input node of the first T-coil circuit.

13. A system comprising:
a source device including a switch circuit comprising:
one or more T-coil circuits comprising a first T-coil circuit, each of the one or more T-coil circuits including:
a respective capacitor; and
two respective inductors coupled in series with each other via a secondary input node of the T-coil circuit, wherein the capacitor of the T-coil circuit is coupled in parallel with the two inductors of the T-coil circuit between a primary input node of the T-coil circuit and an output node of the T-coil circuit;

a first input to receive a first signal;
a first switch coupled between the first input and the primary input node of the first T-coil circuit, the first switch to switchedly configure a first signal path for the first signal;
a second input to receive a second signal; and
a second switch coupled between the second input and the secondary input node of the first T-coil circuit, the second switch to switchedly configure a second signal path for the second signal;

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Assignees

• Lattice Semiconductor Corp

Inventors

• Tirunagari Prashanth
• Agrawal Vinayak
• Sharma Namrta
• Manchikalapudi Manjusha
• Velitheri Rahul

Classifications

• H03K17/16 Primary

  Modifications for eliminating interference voltages or currents · CPC title

• H03K19/0175 Primary

  Coupling arrangements; Interface arrangements (interface arrangements for digital computers G06F3/00, G06F13/00) · CPC title