TUSB2043

4-PORT HUB FOR THE UNIVERSAL SERIAL BUS

WITH OPTIONAL SERIAL EEPROM INTERFACE

SLLS308A – FEBRUARY 1999 – REVISED AUGUST 1999

2

POST OFFICE BOX 655303

description (continued)

Configuring the GANGED input determines the power switching and over-current detection modes for the

downstream ports. External power management devices such as the TPS2044 are required to control the 5-V

source to the downstream ports according to the corresponding values of the PWRON pin. Upon detecting any

over-current conditions, the power management device sets the corresponding OVRCUR pin of the TUSB2043

to a logic low. If GANGED is high, all PWRON outputs switch together and if any OVRCUR is activated, all ports

transition to power-off state. If GANGED is low, the PWRON outputs and OVRCUR inputs operate on a per port

basis.

The EXTMEM pin enables or disables the optional EEPROM interface. When the EXTMEM pin is high, the

product ID (PID) displayed during enumeration is General-Purpose USB Hub. For this default, pin 5 is disabled

and pin 6 functions as the GANGED input pin. If custom PID and Vendor ID (VID) descriptors are desired, the

EXTMEM pin must be low (EXTMEM = 0). For this configuration, pin 5 and pin 6 function as the EEPROM

interface with pin 5 and pin 6 functioning as the EECLK and EEDATA, respectively. See Table 1 for a description

of the EEPROM memory map.

Other useful features of the TUSB2043 include a package with a 0.8 mm pin pitch for easy PCB routing and

assembly, push-pull outputs for the PWRON pins eliminate the need for pullup resistors required by traditional

open collector I/Os, and OVRCUR pins with noise filtering for increased immunity to voltage spikes.