i'm using CY7C68013A-56BAXC, and EEPROM in the board. i have a problem when connect the board with galaxy s9 series. some boards work properly. but other boards does not recognized. and 5v power is not supplied from mobile.
1. If the signal on the DM and connector of the connector is open, the power of the board that was not turned on is also turned on.
2. When the DM and DP signals to the connector are connected, some boards are recognized and others are not.
3. Boards that are not recognized are not powered.
Please let me know how your board is designed and how its connected to the Mobile:
1. Does it have a type C plug (dongle design) or does it have a Type-C receptacle and you are using a type C cable to connect it.
2. Please share the schematics of your board design.
3. Is the problem specific to Samsung Galaxy S9 series?
thank you for reply
1. We use the connector by connecting it directly to the mobile.
connector model is 1007-24M.
2. We cannot deliver it because of the company's policy. Sorry.
3. The problem is with the S9 series. And the next series is the same. When connecting to the S9 series, 5 out of 10 are recognized and the rest are not recognized. But the S8 series is fine.
We only accept DM and DP signals and Vbus from the usb connector. The sequence recognized when connecting to mobile is curious. What are the roles of DM and DP in the recognition process?
In the PCB layout, 90 ohm impedance matching was done and the tracking width and routing length were also modified.
Please probe and check the VBUS and CC line voltages level traces when the board is connected to the Samsung Mobile Device.
Check if the voltage level on the CC pin (A5) is around 2.18V and if there is any VBUS voltage spike on connect.
Please do share the oscilloscope traces.
When using a Type C connector, all the VBUS pins (A9, A4, B9, B4) from the connector should be tied together and supplied as a single VBUS rail to the device and all the Ground pins (A1, A12, B1, B12) from the connector should be tied to ground.
It is recommended to have ESD protection on VBUS, D+ and D- pins.
Please refer to this KBA: Designing FX3™/CX3-Based USB Type-C Products - KBA218460 for an example on Type C based designs. You can leave the Superspeed Tx and RX lines unconnected.