公开(公告)号：US10002101B2

公开(公告)日：2018-06-19

申请号：US14641170

申请日：2015-03-06

Applicant: Apple Inc.

Inventor： Songping Wu ,  Zhiping Yang ,  Kirill Kalinichev ,  Greg Nayman ,  Georgi Beloev

IPC: G06F13/00 ,  G06F13/42 ,  G06F13/40 ,  G06F1/32

CPC classification number: G06F13/4282 ,  G06F1/3287 ,  G06F13/4022

Abstract: Methods and apparatus for equalization of a high speed serial bus. A well-tuned passive equalization circuit for use with high frequency differential signals suffer from e.g., impedance mismatches, impedance discontinuities (e.g., connectors, etc.). In one embodiment, a shunting circuit is inserted between the differential terminals of a Universal Serial Bus (USB) cable, connector, etc. The shunting circuit is configured to “open” at low frequencies to enable Full Speed (FS) enumeration, while also providing sufficiently high impedance at high frequencies to enable High Speed (HS) operation. In one such implementation, the shunting circuit includes a tuned resistor, capacitor, inductor, and switch element arranged in series.