Communication circuit with impedance matching

Patent metadata

Field	Value
Publication number	US-9537462-B2
Application number	US-201414286057-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 23, 2014
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

Aspects of the present disclosure are directed to addressing impedance-matching issues. As may be implemented in connection with one or more embodiments, an apparatus includes an integrated circuit (IC) chip having a signal-connection terminal and processing circuitry that passes signals along a communication path that is within the IC chip and connected to the signal-connection terminal. Impedance-matching circuitry operates to provide impedance-matching for the communication path, therein mitigating signal loss due to impedance-mismatching. A chip-mounting structure secures the IC chip and electrically connects thereto at the signal-connection terminal.

First claim

The invention claimed is:

1. An apparatus comprising:
an integrated circuit (IC) chip including:
a signal-connection terminal;
processing circuitry configured and arranged to pass signals along a communication path within the IC chip and connected to the signal-connection terminal; the processing circuitry including a switch circuit that is configured to selectively connect the signal-connection terminal to a channel from a plurality of channels connectable by the switch, the switch circuit introducing loading on the communication path that creates impedance-mismatching for a particular channel of the plurality of channels; and
impedance-matching circuitry configured and arranged to provide impedance-matching for the communication path and the particular channel, therein mitigating signal loss due to the impedance-mismatching; and

a chip-mounting structure configured and arranged to secure the IC chip and to electrically connect thereto at the signal-connection terminal; and
wherein the signal-connection terminal includes a plurality of connector pads on a lower surface of the IC chip, and the impedance-matching circuitry includes respective inductive circuits connected to each of the connector pads, each inductive circuit being configured and arranged to provide an impedance at the connector pad to which it is connected that matches an impedance of a communication path between the connector pad and an external load coupled thereto.

2. The apparatus of claim 1 , wherein the impedance-matching circuitry includes a variable-length inductor circuit and is configured and arranged to:
detect an external impedance provided by an external load and interconnections between the external load and the signal-connection terminal, and
provide the impedance-matching for the communication path by dynamically modifying the length of the variable-length inductor circuit and matching the detected impedance via the modified length.

3. The apparatus of claim 2 , wherein the impedance-matching circuitry includes at least one switch connected to the variable-length inductor and configured and arranged to modify inductance provided by the inductive circuit by connecting and disconnecting portions of the variable-length inductor.

4. The apparatus of claim 1 , wherein the impedance-matching circuitry includes an inductor on the particular channel, and the impedance-matching circuitry is configured and arranged to provide the impedance-matching for the communication path by using the switch circuit to connect the particular channel to the signal-connection terminal and thereby connecting the inductor to the signal-connection terminal.

5. The apparatus of claim 1 , wherein
the IC chip is configured and arranged to provide a capacitance, and
the impedance-matching circuitry includes an inductor that is configured and arranged with the IC chip to provide an LC circuit, having an impedance that matches an impedance presented to the IC chip via the signal-connection terminal, by using the capacitance provided by the IC chip and an inductance provided by the inductor, wherein the impedance-matching circuitry is configured and arranged to provide the LC circuit having the impedance by creating resonance with the capacitance.

6. The apparatus of claim 1 , wherein the impedance-matching circuitry includes a variable inductor circuit and is configured and arranged to:
detect an external impedance provided by an external load and interconnections between the external load and the signal-connection terminal, and
provide the impedance-matching for the communication path by dynamically modifying the inductance of the inductor circuit.

7. The apparatus of claim 1 , wherein the impedance-matching circuitry and the processing circuitry are embedded within a silicon layer of the IC chip, and wherein the IC chip is connected to the chip-mounting structure via bond pads including the signal-connection terminal and without using bond wires.

8. The apparatus of claim 1 , wherein
the IC chip has a lower planar surface and the signal-connection terminal is on the lower planar surface; and
the chip-mounting structure has an upper planar surface in contact with the lower planar surface of the IC chip, and another signal connection terminal on the upper planar surface in contact with the signal-connection terminal.

9. The apparatus of claim 1 , wherein the impedance-matching circuitry is configured and arranged to match an impedance provided by an external load connected to the signal-connection terminal via the chip-mounting structure, and to mitigate signal loss along a communication path along which the signals are passed between the processing circuitry and the external load.

10. The apparatus of claim 1 , wherein
the communication path includes interconnect circuitry that connects the processing circuitry to the signal-connection terminal, and
the impedance-matching circuitry and the interconnect circuitry are in a common silicon layer of the IC chip, and the impedance-matching circuitry is spaced apart from the interconnect circuitry by a portion of the silicon that mitigates inductive coupling between the impedance-matching circuitry and the interconnect circuitry.

11. The apparatus of claim 1 , wherein the impedance-matching circuitry is configured and arranged to provide an impedance to the signal-connection terminal based on a signal speed of the signals passed along the communication path.

12. The apparatus of claim 1 , wherein the IC chip has a lower planar surface with the signal-connection terminal being proximal to the lower planar surface and being connected to a chip-mounting node via the terminal, and wherein the impedance-matching circuitry is connected with the signal-connection terminal.

13. The apparatus of claim 1 :
wherein the impedance-matching circuitry includes an inductor in an inductive circuit located between the switch circuit and the signal-connection terminal.

14. A method comprising:
passing signals along a communication path within an integrated circuit (IC) chip, the IC chip including a signal-connection terminal and processing circuitry, the signal-connection terminal being electrically connected to a chip-mounting structure that secures the IC chip, the signals being passed via the signal-connection terminal;
selectively connecting the communication path to ports from a plurality of ports using a switch circuit that introduces a load that creates impedance-mismatching for the communication path when at least one of the plurality of ports is connected by the switch circuit; and
mitigating signal loss due to the impedance-mismatching, by providing impedance-matching for the communication path using an inductive circuit located between the switch circuit and the signal-connection terminal, the impedance matching being provided in response to the at least one of the plurality of ports being connected to the communication path by the switch circuit; and
wherein the signal-connection terminal includes a plurality of connector pads on a lower surface of the IC chip, and further including impedance-matching circuitry that includes respective inductive circuits connected to each of the connector pads, each inductive circuit being configured and arranged to provide an impedance at the connector pad to which it is connected that matches an impedance of a communication path between the connector pad and an external load coupled thereto.

15. The method of claim 14 , wherein mitigating signal loss due to impedance-mismatching includes using an inductor and a capacitance provided by the IC chip to match an impedance presented

Assignees

• Nxp Bv
• Nxp Bv

Inventors

• Vemula Madan
• Spehar James

Classifications

• H10W90/724

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/252

  comprising solid metals or solid metalloids, e.g. PbSn, Ag or Cu · CPC title

• H10W44/234

  Arrangements for impedance matching · CPC title

• H10W44/20

  at high-frequency [HF] or radio frequency [RF] · CPC title

• H03H11/30

  Automatic matching of source impedance to load impedance · CPC title