XR22801 Datasheet, PDF (6/42 Pages) Exar Corporation – Hi-Speed USB to 10/100 Ethernet Bridge

XR22801
Pin No.
Pin Name
11
3V3_OUT
12
GND
13
ETH_TX–
14
ETH_TX+
15
ETH_RX+
16
ETH_RX–
17
E0/RI#/RWK#/G0
18
E1/CD#/G1
19
ETH_LINK
20
CAP2
21
GND
22
GND
23
E6/RX/RWK#
24
E7/TX
25
E5/RTS#/RS485/G5
26
E4/CTS#/G4
27
LOW_PWR#
28
GND
29
E2/DSR#/G2
30
E3/DTR#/G3
31
SCL
32
SDA
Type
PWR
PWR
O
O
I
I
I/O
I/O
O
I
PWR
PWR
I/O
I/O
I/O
I/O
O
PWR
I/O
I/O
I/O OD
I/O OD
Description
3.3 V output power. Connect externally to CAP1 and CAP2 using short trace and decouple
with minimum of 4.7uF capacitor
Power supply common, ground
Ethernet transmit data out negative
Ethernet transmit data out positive
Ethernet receive data in positive
Ethernet receive data in negative
Enhanced general purpose IO, or UART Ring Indicator, or remote wakeup, or general purpose
IO. Defaults to UART GPIO input. Refer to Remote Wakeup section on page 9.
Enhanced general purpose IO, or UART Carrier Detect, or general purpose IO. Defaults to
UART GPIO input.
Ethernet 10/100 Activity Indicator. Toggles with activity
Connect externally to CAP1 and 3V3_OUT using short trace
Power supply common, ground
Power supply common, ground
Enhanced general purpose IO, or UART RX data, or remote wakeup. Defaults to UART RX
data.
Enhanced general purpose IO, or UART TX data. Defaults to UART TX data.
Enhanced general purpose IO, or UART Request to Send, or auto-RS485 half-duplex enable,
or general purpose IO. Defaults to UART GPIO input except when XR22801 is used with CDC-
ACM driver. Refer to Automatic RTS/CTS Hardware Flow Control section on page 13 or Auto
RS-485 Half-Duplex Control on page 14.
Enhanced general purpose IO, or UART Clear to Send, or general purpose IO. Defaults to
UART GPIO input except when XR22801 is used with CDC-ACM driver. Refer to Automatic
RTS/CTS Hardware Flow Control section on page 13.
The LOW_PWR# pin will be asserted whenever it is not safe to draw the amount of current
requested from VBUS in the Device Maximum Power field of the Configuration Descriptor. The
LOW_PWR# pin is asserted when the XR22801 is in suspend mode or when it is not yet con-
figured. The LOW_PWR# pin will be de-asserted whenever it is safe to draw the amount of
current requested in the Device Maximum Power field. Note that the XR22801 device is a high
power device. The default polarity of the LOW_PWR# output pin is active low and is program-
mable via the OTP.
Power supply common, ground
Enhanced general purpose IO, or UART Data Set Ready, or general purpose IO. Defaults to
UART GPIO input. Refer to Automatic DTR/DSR Hardware Flow Control section on page 13.
Enhanced general purpose IO, or UART Data Terminal Ready, or general purpose IO. Defaults
to UART GPIO input. Refer to Automatic DTR/DSR Hardware Flow Control section on
page 13.
I²C Master controller serial clock (open-drain) External pull-up resistor required on this pin.
I²C Master controller data (open-drain). External pull-up resistor required on this pin.
Type: I = Input, O = Output, I/O = Input/Output, PWR = Power, OD = Open-Drain
© 2015 Exar Corporation
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exar.com/XR22801
Rev 1B