Method And System For Split Voltage Domain Transmitter Circuits

• US 20170257171A1
• Filed: 05/16/2017
• Published: 09/07/2017
• Est. Priority Date: 10/02/2007
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Luxtera Incorporated (Cisco Systems, Inc.)
• Inventors: Welch, Brian, Kucharski, Daniel
• Granted Patent: US 10,367,664 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/4201 Packages, e.g. shape, construction, internal or external details
• CPC Class Codes: G02B 6/4242 Mounting of the optical light guide to the lid of the package
• CPC Class Codes: H04B 10/501 Structural aspects
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04B 10/564 Power control
• CPC Class Codes: H04B 10/60 Receivers
• CPC Class Codes: H04B 10/693 Arrangements for optimizing the preamplifier in the receiver
• CPC Class Codes: H04L 25/0272 Arrangements for coupling to multiple lines, e.g. for differential transmission
• CPC Class Codes: H04L 25/061 providing hard decisions only; arrangements for tracking or suppressing unwanted low frequency components, e.g. removal of dc offset removal of dc offset in coupling arrangements H04L25/029, H04L25/0296

Abstract

Methods and systems for split voltage domain transmitter circuits are disclosed and may include a two-branch output stage including a plurality of CMOS transistors, each branch of the two-branch output stage comprising two stacked CMOS inverter pairs from among the plurality of CMOS transistors; the two stacked CMOS inverter pairs of a given branch being configured to drive a respective load, in phase opposition to the other branch; and a pre-driver circuit configured to receive a differential modulating signal and output, to respective inputs of the two stacked CMOS inverters, two synchronous differential voltage drive signals having a swing of half the supply voltage and being DC-shifted by half of the supply voltage with respect to each other. The load may include a series of diodes that are driven in differential mode via the drive signals. An optical signal may be modulated via the diodes.

Claims

1. An integrated electro-optical modulator interface comprising:

a two-branch output stage comprising a plurality of CMOS transistors, each branch of said two-branch output stage comprising two stacked CMOS inverter pairs from among said plurality of CMOS transistors;

said two stacked CMOS inverter pairs of a given branch being configured to drive a respective load, in phase opposition to the other branch; and

a pre-driver circuit configured to receive a differential modulating signal and output, to respective inputs of said two stacked CMOS inverters, two synchronous differential voltage drive signals having a swing of half the supply voltage and being DC-shifted by half of the supply voltage with respect to each other.

2. The integrated electro-optical modulator interface according to claim 1, wherein said load comprises a series of diodes that are driven in differential mode via said drive signals.

3. The integrated electro-optical modulator interface according to claim 2, comprising modulating an optical signal via said diodes.

4. The integrated electro-optical modulator interface according to claim 2, wherein said diodes are integrated in a Mach-Zehnder modulator.

5. The integrated electro-optical modulator interface according to claim 2, wherein said diodes are connected in a distributed configuration.

6. The integrated electro-optical modulator interface according to claim 2, comprising communicating said amplified signals to said diodes via transmission lines.

7. The integrated electro-optical modulator interface according to claim 6, wherein said transmission lines are even-mode coupled.

8. The integrated electro-optical modulator interface according to claim 1, further comprising circuitry tying middle nodes of each branch of said two-branch output stage to one of respective supply voltage rails and an additional half supply voltage rail.

9. The integrated electro-optical modulator interface according to claim 1, comprising generating a voltage domain boundary value of one half the supply voltage via symmetric stacked circuits.

10. An electro-optical modulator interface comprising:

a two-branch output stage, each branch comprising a plurality of stacked CMOS inverter pairs;

said plurality of stacked CMOS inverter pairs of a given branch being configured to drive a respective load in phase opposition to the other branch; and

a pre-driver circuit coupled to said plurality of stacked CMOS inverter pairs and configured to generate two synchronous differential voltage drive signals having a swing of half a supply voltage and being DC-shifted by half of the supply voltage with respect to each other.

11. The electro-optical modulator interface according to claim 10, wherein said load comprises a series of diodes that are driven in differential mode via said drive signals.

12. The electro-optical modulator interface according to claim 11, wherein said one or more circuits modulates an optical signal via said diodes.

13. The electro-optical modulator interface according to claim 11, wherein said diodes are integrated in a Mach-Zehnder modulator.

14. The electro-optical modulator interface according to claim 11, wherein said diodes are integrated in a ring modulator.

15. The electro-optical modulator interface according to claim 11, wherein said diodes are connected in a distributed configuration.

16. The electro-optical modulator interface according to claim 11, wherein said one or more circuits communicates said amplified signals to said diodes via transmission lines.

17. The electro-optical modulator interface according to claim 16, wherein said transmission lines are even-mode coupled.

18. The electro-optical modulator interface according to claim 10, further comprising circuitry tying middle nodes of each branch of said two-branch output stage to one of respective supply voltage rails and an additional half supply voltage rail.

19. A method of electro-optical interfacing using an electro-optical modulator interface comprising a two-branch output stage, each branch comprising a plurality of stacked CMOS inverter pairs, the method comprising:

driving, using the plurality of stacked CMOS inverter pairs of a given branch, a respective load coupled between an output of each of the plurality of stacked CMOS inverter pairs in phase opposition to the other branch; and

generating, using a pre-driver circuit coupled to the plurality of stacked CMOS inverter pairs, two synchronous differential voltage drive signals having a swing of half a supply voltage and being DC-shifted by half of the supply voltage with respect to each other.

20. The method according to claim 19, further comprising circuitry tying middle nodes of each branch of said two-branch output stage to one of respective supply voltage rails and an additional half supply voltage rail.