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:
May. 11, 2021
Filed:
Nov. 15, 2019
Texas Instruments Incorporated, Dallas, TX (US);
Win Naing Maung, Plano, TX (US);
Charles Michael Campbell, Wylie, TX (US);
TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US);
Abstract
An input/output (I/O) level shifter for a subscriber identification module (SIM) interface includes a controller configured to apply a first enable signal to turn ON a first transmitter when the direction of packet flow is from an interface device to a SIM card, and is configured to apply a second enable signal to turn ON a second transmitter when the direction of packet flow is from the SIM card to the interface device. The controller is configured to not apply the first and the second enable signals concurrently. The controller selectively controls the ON/OFF period of the first and the second transmitter to maintain half-duplex communication on the interface I/O line and the SIM I/O line to prevent undesired positive data feedback.