FTLF1421S1XCL 2x10 Pin SFF Product Specification – March 2006
Finisar
VIII. Analog Diagnostics Functions
(T
op
= -10 to 70
°C,
V
CC
= 3.00 to 3.60 Volts)
Parameter
Transmitter
Monitor photodiode current monitor
Laser bias current monitor
Receiver
Received photocurrent
Photodiode responsivity
Applied voltage at PD pin
Symbol
Pmon+,
Pmon-
Bmon+,
Bmon-
Rpd
R
Vpd
Min
0
0
Typ
Max
Vcc
Vcc
Unit
V
V
Ref.
1
2
0
0.5
2.4
0.9
1
1.0
Vcc
mA
A/W
V
3
3
Notes:
1. Pins 19 and 20 provide an analog voltage output proportional to the monitor photodiode current,
per the following formula: I
BIAS
= .V(Pmon+ - Pmon-) / 200Ω. The figure below shows the
equivalent circuit.
2. Pins 17 and 18 provide an analog voltage output proportional to the laser bias current, per the
following formula: I
BIAS
= .V(Bmon+ - Bmon-) / 10Ω. The figure below shows the equivalent
circuit.
3. Pin 1 is used to monitor the received photocurrent. It must be connected to a positive voltage
within the range specified above. The current that flows into this pin is the received photocurrent.
The received power is given by the photocurrent multiplied by the photodiode responsivity.
Vcc
Laser
3 KΩ
Bmon+
10
Ω
Bmon-
3 KΩ
Ibias
Imon
3 KΩ
200
Ω
Pmon-
Receiver
Photodidoe
Vcc
Monitor
Photodidoe
Ipd
3 KΩ
Pmon+
Vpd
Analog monitoring function connections.
©
Finisar Corporation March, 2006 Rev A
Page 6
FINISAR [ FINISAR CORPORATION. ]
