CYUSB3324 - ATA Host charging

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RoPr_4700606
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We have a custom board designed for use with the CYUSB3324 part. We are able to use the board as a hub, with the ID shorted to ground. If we hook the ID thru the 73.2Kohm to ground (Samsung tablet), there is no enumeration. I have read the data sheet and the app note KBA96321. The parts is strapped for internal ROM, with strapping as defined in the data sheet Table 6. VBUS_US is connected to 5V.

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yali_4701491
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did you try 80K resistor at ID pin as suggested in KBP96321 ?

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Sananya_14
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750 replies posted 500 replies posted 250 solutions authored

Hello,

-Could you please confirm if the RID_A value for the Samsung tablet is 73.2kohm?

-Could you please check if the US_PWREN pin is asserted? Is the hub asserting the SUSPEND pin after the tablet is connected?

Best Regards,

Sananya

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-We have a decade box hooked up to the ID pin, so yes we have tried 73.2K.

-If we hookup with the 73.2K, the US_PWREN pin appears to stay asserted (low), and the chip stays in suspend. When we are in VLC, it says USB connected, and then USB disconnected. We are using the TI part TPS2556, and with US_PWREN low, it is applying power to the US_VBUS power pin the whole time.

--If we ground the ID, re-hookup the CYUSB3324 board, the part enumerates and comes out of suspend.

--On the downstream ports, the development boards hook 100ohms across VBUS power if the power is not applied. This is not present on the US_VBUS in your kits.

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yali_4701491
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did you try 80K resistor at ID pin as suggested in KBP96321 ?

After getting my head screwed on straight, I used 80K and it is working. Thanks for your help. Note, cable length seems to affect the results.

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RoPr_4700606
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I was able to get the evaluation board to charge the tablet with USB traffic, however something failed on the board. Looking for the fault. We were using 73.2K for the ID resistor.

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Try 80K

On Thu, May 21, 2020 at 7:03 PM RoPr_4700606 <community-manager@cypress.com>

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