The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 17, 2025
Filed:
Jan. 28, 2022
Texas Instruments Incorporated, Dallas, TX (US);
Shita Guo, Dallas, TX (US);
Amit S. Rane, Santa Clara, CA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
An eye expander that increases the transmitter linearity of Pulse-Amplitude Modulation 4-Level (PAM4) signals having an inner eye and two outer eyes. In embodiments, the eye expander includes a semi-linear gain stage that increases the eye height of the outer eyes. In some of those embodiments, the semi-linear gain stage includes a semi-linear gain input transistor having a base or gate coupled to an input terminal and a collector or drain coupled to an output terminal, a semi-linear gain resistor coupled to the emitter or source of the semi-linear gain input transistor, and semi-linear gain transistor-resistor pairs that selectively connect the emitter or source of the semi-linear gain input transistor to ground. In some embodiments, the eye expander includes a limiting gain stage that reduces the eye height of the inner eye and a linear gain stage that increases the eye height of the inner and outer eyes.