USB 2.0 Hi-Speed 3-Port Hub Controller Optimized for Portable Applications
Datasheet
Table 8.2 CHRGDET[1:0] Configuration Definitions (continued)
CHRGDET[1:0]
DEFINITION
‘11’
Charger detected.
Draw battery charger current from VBUS (1.0A+).
Note:
The actual current amount for the charger will be
system dependant.
8.1.2
Downstream Battery Charging
The device can be configured by an OEM to have the downstream ports to support battery charging.
The Hub's role in battery charging is to provide an acknowledge to a device's query as to if the hub
system supports USB battery charging. The hub silicon does not provide any current or power FETs
or any additional circuitry to actually charge the device. Those components must be provided as
externally by the OEM.
DC Power
INT
SCLSMSC
SOC
SDA
Hub
PRTPWRA
VBUS[n]
Figure 8.1 Battery Charging External Power Supply
If the OEM provides an external supply capable of supplying current per the battery charging
specification, the hub can be configured to indicate the presence of such a supply to the device.This
indication, per the PRTCTLA output, is for all downstream ports.
Note: Battery charging is not available on downstream HSIC ports.
8.1.2.1
Downstream Battery Charging Modes
In the terminology of the USB Battery Charging Specification, if a port is configured to support battery
charging, the downstream port is a considered a CDP (Charging Downstream Port) if connected to a
USB host, or a DCP (Dedicated Charging Port) if not connected to a USB host. If the port is not
configured to support battery charging, the port is considered an SDP (Standard Downstream Port).
All charging ports have electrical characteristics different from standard non-charging ports.
SMSC USB3813
51
Revision 1.0 (06-17-13)
DATASHEET
SMSC [ SMSC CORPORATION ]
