Delta Electronics LCP-1250 specifications Pld / Pal

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

VCC 3.3V 1uH

Protocol Vcc

RES1

Tx_Disable

Tx_Fault

Protocol IC SerDes IC

1uH DELTA SFP Module

10uF 0.1uF

0.1uF VccT

10k Ohms

Tx_Disable

Tx_Fault
TD +	0.01uF
	Laser Driver
	100 Ohms
	Laser Diode
TD -	0.01uF
VeeT

RES1	0.1uF	VccR
10uF
	RD +	0.01uF

100 Ohms*

RD - 0.01uF

Rx_LOS

3.3V	Rx_LOS
	VeeR
RES1 RES1 RES1

Preamp &

Quantizer

Photo Diode

PLD / PAL

Mod_def 2

Mod_def 1

Mod_def 0

EEPROM

RES1 = 4.7k to 10k Ohms

* Depands on SerDes IC used

6	Nov., 2006
	Rev. 6B
DELTA ELECTRONICS, INC.	www.deltaww.com