AT43312 Datasheet, PDF (1/21 Pages) ATMEL Corporation – Self- and Bus- Powered USB Hub Controller

Features
• Full compliance with USB spec Rev 1.0
• Four downstream ports
• Full speed and low speed data transfers
• Self-Powered or Bus-Powered modes of operation
• Per port overcurrent monitoring
• Individual port power switch control
• USB connection status indicators
Description
The AT43312 is a 5 port USB hub chip supporting one upstream and four downstream
ports. The AT43312 connects to an upstream hub or Host/Root Hub via Port0 and the
other ports connect to external downstream USB devices. The hub re-transmits the
USB differential signal between Port0 and Ports[1:4] in both directions. A USB hub
with the AT43312 can operate as a bus-powered or self-powered through chip’s
power mode configuration pin. The AT43312 is pin- and function-compatible with the
AT43311 and can be used as a replacement for the AT43310 with one pin modifica-
tion.
The AT43312 supports the 12 Mb/s full-speed as well as 1.5 Mb/s slow-speed USB
transactions. To reduce EMI, the AT43312’s oscillator frequency is 6 MHz even
though some internal circuitry operates at 48 MHz.
Self- and Bus-
Powered USB
Hub Controller
AT43312
Pin Configurations
SOIC/DIP
PWR2 1
PWR3 2
PWR4 3
VCC5 4
GND 5
OSC1 6
OSC2 7
LFT 8
VCCA 9
OVL4 10
OVL3 11
OVL2 12
OVL1 13
VREF 14
BUS/SELF 15
STAT4 16
32 PWR1
31 DP4
30 DM4
29 DP3
28 DM3
27 GND
26 DP2
25 DM2
24 VCC3
23 DP1
22 DM1
21 DP0
20 DM0
19 STAT1
18 STAT2
17 STAT3
Rev. 1002A-A–01/98
1