lxt972a Intel Corporation, lxt972a Datasheet - Page 14

• Manufacturer Part Number: lxt972a
• Description: 3.3v Dual-speed Fast Ethernet Transceiver Datasheet
• Manufacturer: Intel Corporation

LXT972A — 3.3V Dual-Speed Fast Ethernet Transceiver Datasheet
14
1. Type Column Coding: I = Input, O = Output, A = Analog, OD = Open Drain
1. Type Column Coding: I = Input, O = Output, A = Analog, OD = Open Drain
LQFP
Pin#
LQFP
9, 10,
19
20
23
24
Pin#
Table 3.
Table 4.
12
17
33
34
35
39
44
5
6
4
1
2
TPOP
TPON
TPIP
TPIN
TxSLEW0
TxSLEW1
RESET
ADDR0
RBIAS
PAUSE
TEST0
TEST1
PWRDWN
REFCLK/XI
XO
N/C
Symbol
Symbol
LXT972A Network Interface Signal Descriptions
LXT972A Miscellaneous Signal Descriptions
Type
Type
O
I
AI
O
I
I
I
I
I
I
I
I
-
1
1
Twisted-Pair Outputs, Positive & Negative.
During 100BASE-TX or 10BASE-T operation, TPOP/N pins drive 802.3 compliant
pulses onto the line.
Twisted-Pair Inputs, Positive & Negative.
During 100BASE-TX or 10BASE-T operation, TPIP/N pins receive differential
100BASE-TX or 10BASE-T signals from the line.
Tx Output Slew Controls 0 and 1. These pins select the TX output slew rate (rise
and fall time) as follows:
TxSLEW1
0
0
1
1
Reset. This active Low input is OR’ed with the control register Reset bit (0.15). The
LXT972A reset cycle is extended to 258 s (nominal) after reset is deasserted.
Address0. Sets device address.
Bias. This pin provides bias current for the internal circuitry. Must be tied to ground
through a 22.1 k
Pause. When set High, the LXT972A advertises Pause capabilities during auto
negotiation.
Test. Tie Low.
Test. Tie Low.
Power Down. When set High, this pin puts the LXT972A in a power-down mode.
Crystal Input and Output. A 25 MHz crystal oscillator circuit can be connected
across XI and XO. A clock can also be used at XI. Refer to Functional Description for
detailed clock requirements.
No Connection. These pins are not used and should not be terminated.
TxSLEW0
0
1
0
1
, 1% resistor.
Signal Description
Signal Description
Slew Rate (Rise and Fall Time)
2.5 ns
3.1 ns
3.7 ns
4.3 ns
Datasheet