CY7C65211A Data Line Voltage for DCP

[Pingelw]

What profiles are accepted by the CY7C65211A in device recognition / BCD configuration? What voltages are allowed / expected on D+ and D-? 

We are testing a new product with several different AC adapters for USB charging, 2 of which work perfectly and 1 of which enters a charging suspend state. We have not until now expected to define compatible chargers, and would like to understand if that is necessary and what qualities are necessary. 

Chargers 1 & 2 configure the BCD to DCP, allowing full charging ✔️

• D- = 3.3V
• D+ = 3.3V

Charger 3 configures the BCD to suspend, preventing charging ✖️

• D- = 3.6 V
• D+ = 4.0 V

In general, the CY7C65211A  has performed well for us for UART communication and most BCD configuration for charging. We would like to understand if this issue has demonstrated we have made an error in design or configuration, or if Charger 3's data line voltage is not supported by the CY7C65211A . 

[MallikaK_22 · Accepted solution]

Hi,

For the different stages (primary and secondary detection) in BC1.2, voltage in the range of (0.5-0.7V) on D+ and <0.4V on D- (vice versa for secondary detection are observed). Since, CY7C65211A supports BCD and complies with the USB Battery Charging Specification, the voltage levels on USB-serial should not be a problem. Regarding the values you have provided for charger 3, they are the values when the device is in suspend mode. In this case, the D+ voltage can go up to 3.8V. Also, since the other chargers are getting detected it should not be a hardware issue also. Probably, the 3rd charger is non-BC1.2 compliant. You can try testing with other chargers also.

Regards,

Mallika