• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 1772 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS65982: Pull-down resistor on SBU signal

Antony Lin
Genius 13480 points
Other Parts Discussed in Thread: HD3SS460, TPS65982

i,

Do we need to add 2Mohm resistor to GND on SBU signals when using TPS65982?  It's suggested in HD3SS460, but not mentioned in TPS65982 datasheet.

Thanks!

Antony

  • 0
    TI__Mastermind 30280 points

    The VESA spec says:

    "Figure 3-1 illustrates the system design of a DFP_D on a USB Type-C connector connected to a UFP_D on a USB Type-C connector using a USB Type-C to USB Type-C Cable. The 2MΩ pull-down resistors on SBU1 and SBU2 are representative of the leakage of ESD and EMI/RFI components including termination to ensure no floating nodes, and are intended to show compliance with zSBUTermination in USB Type-C r1.0.

    Note: These schematics do not show the ESD protection and EMI/RFI components typically
    included in the system designs."

    Therefore, the 2MΩ pull-down resistor is not a real resistor, but rather a representation of a leakage resistance. The spec implies that the leakage resistance can also help meet the ZSBUTermination spec in Type-C. If ESD and EMI/RFI components are not used for some reason, zSBUTermination >= 950kΩ is a Type-C requirement.

    Please advise your customer to consult the VESA and spec directly, since we cannot post the document online due to licensing. The Type-C spec is public on the USB website.