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-lead SOIC and 32-lead LQFP
Low-cost USB
Hub Controller
1. 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 is available in a 24-lead SOIC and a 32-lead LQFP packages. The 32-lead ver-
sion of the AT43301, the AT43301-AC, has a 48 MHz clock input.
AT43301
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.
Figure 1-1. Pin Configurations
32-lead LQFP Top View
24-lead SOIC Top View
AT43301-SC
VCC
VSS
1
24
23
22
21
20
19
18
17
16
15
14
13
NC
2
DP4
DM4
DP3
DM3
DP2
DM2
DP1
DM1
DP0
DM0
VSS
CEXT1
OSC1
OSC2
LFT
3
NC
DM4
DP4
1
2
3
4
5
6
7
8
24 NC
23 DP0
4
22 DM0
5
48
21 VSS
AT43301-AC
6
VCC
VSS
CEXT1
NC
20 NC
STAT
7
19 SELF/BUS
18 TEST
17 LPSTAT
PWR
8
OVC
9
LPSTAT
TEST
10
11
12
SELF/BUS
1137J–USB–01/06