1
Features
•
Full Compliance with USB Spec Rev 1.1
•
Four Downstream Ports
•
Full-speed and Low-speed Data Transfers
•
Bus-powered Controller
•
Bus-powered or Self-powered Hub Operation
•
Port Overcurrent Monitoring
•
Port Power Switching
•
5V Operation with On-chip 3.3V Regulator
•
24-pin SOIC
Description
The AT43301 is a 5-port USB hub chip supporting one upstream and four down-
stream ports. The AT43301 connects to an upstream hub or host/root hub via Port0,
while the other ports connect to external downstream USB devices. The hub re-trans-
mits the USB differential signal between Port0 and Ports[1:4] in both directions. The
AT43301 is designed for very low-cost bus-powered or self-powered hub applications
and comes in a 24-pin SOIC package.
The AT43301 supports the 12 Mb/s full speed as well as 1.5 Mb/s slow speed USB
transactions. To reduce EMI, the AT43301’s oscillator frequency is 6 MHz even
though some internal circuitry operates at 48 MHz.
Low-cost USB
Hub Controller
AT43301
Rev. 1137C–08/99
Pin Configurations
Top View
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
VCC
VSS
CEXT1
OSC1
OSC2
LFT
STAT
PWR
OVC
LPSTAT
TEST
SELF/BUS
NC
DP4
DM4
DP3
DM3
DP2
DM2
DP1
DM1
DP0
DM0
VSS
