CN7221 Datasheet, PDF (13/18 Pages) Conexant Systems, Inc – Home Networking Physical Layer Device with Integrated Analog Front End Circuitry

Home Networking PHY with Integrated AFE
Pin Designations by Group
LANfinity™ CN7221
Home LAN
Table 7. Pin Designations by Group
Pin Name
HLAN_OSC
HLAN_RESET#
HLAN_IRQ#
HLAN_TX_EN
HLAN_TXD
HLAN_TX_CLK
HLAN_COL
HLAN_CRS
HLAN_RXD
HLAN_RX_CLK
HLAN_SPI_CS#
HLAN_SPI_CLK
HLAN_SPI_DOUT
HLAN_SPI_DIN
Type
I
I
O
I
I
O
O
O
O
O
I/O
I/O
O
I
Schmitt Resistive
↓ 25Kohm
↓ 25Kohm
↓ 25Kohm
↑100Koh
m
Drive
CMOS
CMOS
6mA
CMOS
CMOS
6mA
6mA
6mA
6mA
6mA
6mA
6mA
6mA
CMOS
Description
60 MHz oscillator input
Active high asynchronous system reset
Active low processor interrupt
7WS transmit enable
7WS transmit data
7WS transmit clock
7WS collision (active high)
7WS receive carrier sense
7WS receive data
7WS receive clock
Serial interface chip select
Active low
Serial interface clock
Serial data output
Serial data input
AFE Interface (Reference)
Pin Name
Type Schmitt Resistive Drive Description
Pin Number(s)
1
5
22
27
30
31
25
26
23
24
3
4
2
32
Pin Number(s)
AFE_REF_NOISE
AFE_REF_PEAK
AFE_REF_DATA
AFE_RBIAS
AFE_RX_MINUS
AFE_RX_PLUS
AFE_TX_MINUS
AFE_VDD_RX
AFE_VSS_RX
AFE_VSS_TX
AFE_VC
AFE_TX_PLUS
Noise reference filtered with an external 0.0075
7
uF Cap for data CT comparator.
Peak reference filtered with an external 0.0034 uF 8
Cap for peak CT comparator.
Data reference filtered with an external 0.0134 uF 9
Cap for data CT comparator.
External 1% 2.75kOhm resistor to set reference 12
current.
Negative input of the 7.5MHz receive signal
15
Positive input of the 7.5MHz receive signal
16
Negative output of the 7.5MHz TX signal
17
connected to the 50ohm resistor and 1000pF AC
coupling Caps.
RX power supply (3-3.6V or 3.15-3.45)
10
RX ground
11
TX ground
14
Middle point of the power supply filtered with an 13
external 10uF Cap.
Positive output of the 7.5MHz TX signal
18
connected to the 50ohm resistor and 1000pF AC
coupling Caps.
LAN-056, Rev. A
Conexant
13
PROPRIETARY INFORMATION