ZHCSLY5A August 2020 – July 2021 TPS65994AD
PRODUCTION DATA
When configured as a source, the TPS65994AD detects when a cable or a Sink is attached using the Px_CC1 and Px_CC2 pins. When in a disconnected state, the TPS65994AD monitors the voltages on these pins to determine what, if anything, is connected. See USB Type-C Specification for more information.
Table 8-1 shows the Cable Detect States for a Source.
| Px_CC1 | Px_CC2 | CONNECTION STATE | RESULTING ACTION |
|---|---|---|---|
| Open | Open | Nothing attached | Continue monitoring both Px_CCy pins for attach. Power is not applied to Px_VBUS or VCONN. |
| Rd | Open | Sink attached | Monitor Px_CC1 for detach. Power is applied to Px_VBUS but not to VCONN (Px_CC2). |
| Open | Rd | Sink attached | Monitor Px_CC2 for detach. Power is applied to Px_VBUS but not to VCONN (Px_CC1). |
| Ra | Open | Powered Cable-No UFP attached | Monitor Px_CC2 for a Sink attach and Px_CC1 for cable detach. Power is not applied to Px_VBUS or VCONN (Px_CC1). |
| Open | Ra | Powered Cable-No UFP attached | Monitor Px_CC1 for a Sink attach and Px_CC2 for cable detach. Power is not applied to Px_VBUS or VCONN (Px_CC1). |
| Ra | Rd | Powered Cable-UFP Attached | Provide power on Px_VBUS and VCONN (Px_CC1) then monitor Px_CC2 for a Sink detach. Px_CC1 is not monitored for a detach. |
| Rd | Ra | Powered Cable-UFP attached | Provide power on Px_VBUS and VCONN (Px_CC2) then monitor Px_CC1 for a Sink detach. Px_CC2 is not monitored for a detach. |
| Rd | Rd | Debug Accessory Mode attached | Sense either Px_CCy pin for detach. |
| Ra | Ra | Audio Adapter Accessory Mode attached | Sense either Px_CCy pin for detach. |
When a TPS65994AD port is configured as a Source, a current IRpDef is driven out each Px_CCy pin and each pin is monitored for different states. When a Sink is attached to the pin a pull-down resistance of Rd to GND exists. The current IRpDef is then forced across the resistance Rd generating a voltage at the Px_CCy pin. The TPS65994AD applies IRpDef until it closes the switch from PP5V to Px_VBUS, at which time application firmware may change to IRp1.5A or IRp3.0A.
When the Px_CCy pin is connected to an active cable VCONN input, the pull-down resistance is different (Ra). In this case the voltage on the Px_CCy pin will be lower and the TPS65994AD recognizes it as an active cable.
The voltage on Px_CCy is monitored to detect a disconnection depending upon which Rp current source is active. When a connection has been recognized and the voltage on Px_CCy subsequently rises above the disconnect threshold for tCC, the system registers a disconnection.