SLLS414F March 2000 – August 2015 TUSB2077A
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The EXTMEM pin (pin 47) enables or disables the optional EEPROM interface. When EXTMEM is high, the vendor and product IDs (VID and PID) use defaults, such that the message displayed during enumeration is General Purpose USB Hub.
The TUSB2077A supports bus-powered and self-powered modes. External power-management devices, such as the TPS2044, are required to control the 5-V power source switching (on/off) to the downstream ports and to detect an overcurrent condition from the downstream ports individually or ganged. An individually port power controlled hub switches power on or off to each downstream port as requested by the USB host. Also when an individually port power controlled hub senses an overcurrent event, only power to the affected downstream port will be switched off. A ganged hub switches on power to all its downstream ports when power must be on for any port. The power to the downstream ports is not switched off unless all ports are in a state that allows power to be removed. Also, when a ganged hub senses an overcurrent event, power to all downstream ports will be switched off.