USB2412 Ver la hoja de datos (PDF) - SMSC -> Microchip
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USB2412 Datasheet PDF : 27 Pages
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2.3
PIN
#
21
22
18
1
3
28
2
7
11
8
12
26
13
2-Port USB 2.0 Hi-Speed Hub Controller
Datasheet
Pin Descriptions (Grouped by Function)
SYMBOL
USBDM_UP
USBDP_UP
VBUS_DET
USBDP_DN1
USBDP_DN2
USBDM_DN1
USBDM_DN2
PRTPWR1
PRTPWR2
OCS_N1
OCS_N2
RBIAS
NON_REM1
Table 2.2 USB2412 Pin Descriptions
BUFFER
TYPE
DESCRIPTION
UPSTREAM USB 2.0 INTERFACES
IO-U
USB Bus Data: connect to the upstream USB bus data signals (host,
port, or upstream hub).
I/O12
Detect Upstream VBUS Power: detects the state of upstream VBUS
power. The SMSC hub monitors VBUS_DET to determine when to
assert the internal D+ pull-up resistor which signals a connect event.
When designing a detachable hub, this pin should be connected to
VBUS on the upstream port via a 2 to 1 voltage divider.
For self-powered applications with a permanently attached host, this
pin must be connected to a dedicated host control output, or
connected to 3.3 V domain that powers the host.‘
According to Section 7.2.1 of the USB 2.0 Specification 1., a
downstream port can never provide power to its D+ or D- pull-up
resistors unless the upstream port’s VBUS is in the asserted (powered)
state.
VBUS_DET monitors the state of the upstream VBUS signal and will
not pull-up the D+ resistor if VBUS is not active. If VBUS goes from
an active to an inactive state (Not Powered), the hub will remove
power from the D+ pull-up resistor within 10 seconds.
DOWNSTREAM USB 2.0 INTERFACES
IO-U
Hi-Speed USB Data: connect to the downstream USB peripheral
devices attached to the hub’s ports.
I/O12
IPU
I-R
I/O
USB Power Enable: enables power to USB peripheral devices that are
downstream, where the hub supports active high power controllers
only.
Over-Current Sense: input from external current monitor indicating an
over-current condition. This pin contains an internal pull-up to the 3.3 V
supply.
USB Transceiver Bias: a 12.0 kΩ (+/- 1%) resistor is attached from
ground to this pin to set the transceiver’s internal bias settings.
MISC
Non-removable Port Strap Option: this pin is sampled (in conjunction
with SUSP_IND/NON_REM0) at RESET_N negation to determine if
ports [2:1] contain permanently attached (non-removable) devices:
NON_REM[1:0] = 00: all ports are removable
NON_REM[1:0] = 01: port 1 is non-removable
NON_REM[1:0] = 10 and 11: ports 1 and 2 are non-removable
See Section 2.5, "Strap Option Pins" for details.
Revision 1.3 (12-27-11)
10
DATASHEET
SMSC USB2412
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