6

Table 2. 20-pin Connection Diagram Description

Pin

Name

Function/Description

MSA Notes

1

Transmitter Ground

2

TX Fault

Transmitter Fault Indication - High Indicates a Fault

Note 1

3

TX Disable

Transmitter Disable - Module disables on high or open

Note 2

4

MOD-DEF2

Module Definition 2 - Two wire serial ID interface

Note 3

5

MOD-DEF1

Module Definition 1 - Two wire serial ID interface

Note 3

6

MOD-DEF0

Module Definition 0 - Grounded in module

Note 3

7

Rate Select

Not Connected

8

LOS

Loss of Signal - High Indicates Loss of Signal

Note 4

9

Receiver Ground

10

Receiver Ground

11

Receiver Ground

12

RD-

Inverse Received Data Out

Note 5

13

RD+

Received Data Out

Note 5

14

Receiver Ground

15

Receiver Power - 3.3 V +/- 5%

Note 6

16

Transmitter Power - 3.3 V +/- 5%

Note 6

17

Transmitter Ground

18

TD+

Transmitter Data In

Note 7

19

TD-

Inverse Transmitter Data In

Note 7

20

Transmitter Ground

Notes:

1. TX Fault is not used and is always tied to ground through a 100 ohm resistor.

2. TX Disable as described in the MSA is not applicable to the 1000BASE-T module, but is used for convenience as an input to reset the internal

ASIC. This pin is pulled up within the module with a 4.7 K

W resistor.

Low (0 – 0.8 V):

Transceiver on

Between (0.8 V and 2.0 V):

Undefined

High (2.0 – 3.465 V):

Transceiver in reset state

Open:

Transceiver in reset state

3. Mod-Def 0,1,2. These are the module definition pins. They should be pulled up with a 4.7-10 K

W resistor on the host board to a supply less than

Mod Def 0 is tied to ground through a 100 ohm resistor to indicate that the module is present.

Mod-Def 1 is clock line of two wire serial interface for optional serial ID

Mod-Def 2 is data line of two wire serial interface for optional serial ID

4. LOS (Loss of Signal) operation on the 1000BaseT SFP is different than for optical SFP applications. For models with RX_LOS enabled, RX_LOS

signal is a 1000BASE-T linkup/link-down indicator and not a peak (AC) or voltage (DC) detector. For models where RX_LOS is disabled, RX_LOS

is not used and is always tied to ground via 100-ohm resistor.

5. RD-/+: These are the differential receiver outputs. They are ac coupled 100

W differential lines which should be terminated with 100 W differential

at the user SerDes. The ac coupling is done inside the module and is thus not required on the host board. The voltage swing on these lines

will be between 370 and 2000 mV differential (185 – 1000 mV single ended) when properly terminated. These levels are compatible with CML

and LVPECL voltage swings.

current is 317 mA and the associated in-rush current will typically be no more than 30 mA above steady state after 500 nanoseconds.

7. TD-/+: These are the differential transmitter inputs. They are ac coupled differential lines with 100

W differential termination inside the module.

The ac coupling is done inside the module and is thus not required on the host board. The inputs will accept differential swings of 500 – 2400

mV (250 – 1200 mV single ended), though it is recommended that values between 500 and 1200 mV differential (250 – 600 mV single ended)

be used for best EMI performance. These levels are compatible with CML and LVPECL voltage swings.