DELTA ELECTRONICS, INC.

6

Aug., 2006

Rev. 6A

www.deltaww.com

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.

7) VccR and VccT are the receiver and transmitter power supplies. They are defined as 3.3V ±5% at the

SFP connector pin. Maximum supply current is 300mA. Recommended host board power supply

filtering is shown below. Inductors with DC resistance of less than 1 ohm should be used in order to

maintain the required voltage at the SFP input pin with 3.3V supply voltage. When the recommended

supply-filtering network is used, hot plugging of the SFP transceiver module will result in an inrush

current of no more than 30mA greater than the steady state value. VccR and VccT may be internally

connected within the SFP transceiver module.

8) TD-/+: These are the differential transmitter inputs. They are AC-coupled, differential lines with 100Ω

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.

Recommend Circuit Schematic

Laser Diode

Photo Diode

1uH

1uH

0.1uF

10uF

0.1uF

0.01uF

0.01uF

0.01uF

0.01uF

0.1uF

10uF

RES1

RES1

100 Ohms*

RES1

RES1

RES1

10k Ohms

100 Ohms

VCC

Protocol Vcc

SerDes IC

Protocol IC

PLD / PAL

Mod_def 2

Mod_def 1

Mod_def 0

3.3V

3.3V

DELTA SFP Module

Preamp &

Tx_Disable

Quantizer

Tx_Fault

TD +

TD -

VeeT

RD +

RD -

Rx_LOS

VeeR

Tx_Disable

Tx_Fault

Rx_LOS

RES1 = 4.7k to 10k Ohms

VccT

VccR

Laser Driver

* Depands on SerDes IC used

EEPROM