AT43312A Datasheet, PDF (1/27 Pages) ATMEL Corporation – Self and buspowered USB Hub Controller

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
• Per Port Overcurrent Monitoring
• Individual Port Power Control
• USB Connection Status Indicators
• 5V Operation with On-chip 3.3V Format
• 32-lead SOIC and LQFP
Overview
Introduction
The AT43312A is a 5 port USB hub chip supporting one upstream and four down-
stream ports. The AT43312A connects to an upstream hub or Host/Root Hub via Port0
and 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. A USB
hub with the AT43312A can operate as a bus-powered or self-powered through chip’s
power mode configuration pin. In the self-powered mode, port power can be switched
or unswitched. Overcurrent reporting and port power control can be individual or glo-
bal. An on-chip power supply eliminates the need for an external 3.3V supply.
The AT43312A supports the 12-Mb/sec full speed as well as 1.5-Mb/sec slow speed
USB transactions. To reduce EMI, the AT43312A’s oscillator frequency is 6 MHz even
though some internal circuitry operates at 48 MHz.
The AT43312A consists of a Serial Interface Engine, a Hub Repeater, and a Hub
Controller.
Self- and Bus-
powered USB
Hub Controller
AT43312A
SOIC
PWR2 1
PWR3 2
PWR4 3
VCC5 4
VSS 5
OSC1 6
OSC2 7
LFT 8
TEST 9
OVC4 10
OVC3 11
OVC2 12
OVC1 13
LPSTAT 14
SELF/BUS 15
STAT4 16
32 PWR1
31 DP4
30 DM4
29 DP3
28 DM3
27 VSS
26 DP2
25 DM2
24 CEXT
23 DP1
22 DM1
21 DP0
20 DM0
19 STAT1
18 STAT2
17 STAT3
LQFP Top View
DP3 1
DM4 2
DP4 3
PWR1 4
PWR2 5
PWR3 6
PWR4 7
VCC5 8
24 DMO
23 STAT1
22 STAT2
21 STAT3
20 STAT4
19 SELF/BUS
18 LPSTAT
17 OVC1
Rev. 1255F–USB–3/04
1