DTR-622-SM-LC-A-HP-IR OPLINK [OPLINK Communications Inc.], DTR-622-SM-LC-A-HP-IR Datasheet - Page 4

• Manufacturer Part Number: DTR-622-SM-LC-A-HP-IR
• Description: Multi-rate OC-12/STM-4 Single mode SFF Transceivers
• Manufacturer: OPLINK [OPLINK Communications Inc.]

Application Notes
Transmitter: When the DATA+ input is at logic HIGH and
DATA- input is at logic LOW, the Laser Diode is ON; and vice
versa. The transmitter is normally enabled (i.e. when the TX
DISABLE control input is not connected). When the TX
DISABLE control input voltage is higher than V
laser is turned off independent of the input data. The transmitter
has two options for input termination. With “MS” and “MSE”
versions, the transmitter input interface is standard LV-PECL(i.e.
normal resistor termination needs to be provided by the end
user). With the “M” and “ME” version, an internal differential
100 ohm resistor termination is provided at the transmitter input
interface for convenience (see circuit diagrams below.)
The transmitter incorporates an Average Power Control (APC)
loop to stabilize the transmitter average optical output power
against temperature variation. The APC loop always acts to
keep the transmitter average optical output power at a constant
value. Therefore, when the input data is all continuous “zeroes”
or all continuous “ones”, the transmitter optical output power
is a constant level equal to the nominal average optical output
power (not at the “OFF” level or at the “ON” level).
Internal Termination (for “M” & “ME” version)
OC-12/STM-4 LC Single Mode Transceiver: DTR-622-SM-LC/LS-MR
+
10
SIGNAL DETECT
+3.3 volt
ferrite inductor
1 H coil or
TX DISABLE
µ
ferrite inductor
0.1
1 H coil or
µ
0.1
+
10
Capacitor values in F, Resistor values in ohm
8
3
DTR-622-SM-LC-MR
6
7
0.1
POSTS
GND
CC
2
- 1.3 V, the
µ
100
1
10
5
4
9
4
Receiver: Both differential DATA+ and DATA- outputs are LV-
PECL levels requiring proper termination (see recommended
interface circuits). For optimum performance, both outputs
should be terminated in the same manner, even if only one is
used.
The Signal Detect circuit monitors the level of the incoming
optical signal and generates a logic LOW signal when
insufficient photocurrent is produced. If the SIGNAL DETECT
output is LV-TTL level, no termination is required. If the SIGNAL
DETECT output is LV-PECL level, a termination resistor of 160
ohms to GND is required.
Interface circuit: The power supply line should be well-filtered.
All 0.1 µF power supply bypass capacitors should be as close
to the DTR transceiver module as possible. The two front GND
posts (mounting studs) should be grounded to Circuit Ground
or Chassis Ground. The Transmitter has internal 50 ohm
termination (see interface circuits).
TXD+
TXD -
RXD+
RXD -
160
50 ohm line
50 ohm line
160
50 ohm line
50 ohm line
160
100
160
LV-PECL
LV-PECL
21737-0375, Rev. B
06-12-2003