JAJSKH4A April 2022 – May 2024 TUSB1104
PRODUCTION DATA
In Fixed EQ operation, a single EQ setting is used for all possible devices inserted into the USB receptacle (with or without an USB cable). It is recommended to set TUSB1104 CEQ[1:0] pins if pin-strap mode, or CEQ1_SEL and CEQ2_SEL if I2C mode to about 4 db to 5 dB greater than loss of the post channel (XCD). For example, if post channel is 0.5 inches, then assuming -1 dB per inch at 5 GHz, CEQ1_SEL and CEQ2_SEL should be programmed to 4.5 to 5.5 dB. It is recommended to perform USB 3.1 Rx JTOL long and short channel tests to optimize the setting. Depending of the USB 3.2 Host, a single EQ setting which satisfies both the long and short channel tests may not be possible. If this is the case, then it is recommended to use AEQ mode.