1345-Type Receiver with
Clock Recovery and Data Retiming
Data Sheet
January 2000
Description
(continued)
The receiver converts optical signals in the range of
1.1
µm
to 1.6
µm
into retimed clock and data signals.
The clock and data outputs are raised-ECL (PECL)
logic levels. A CMOS-level flag output indicates when
there is a loss of optical signal.
The receiver requires a 5 V power supply for the ampli-
fier, logic, and PLL CRC circuits. The operating case
temperature range is –40 °C to +85 °C.
Flag Output
When the optical input falls below the link status flag
switching threshold, the link status flag is deactivated
and its output logic level changes from a CMOS logic
HIGH to a CMOS logic LOW.
Squelched Data and Clock Outputs
In some versions of the 1345 receiver (see Table 4),
when the link status flag is deactivated, the data and
clock outputs are squelched (stop outputting a signal).
When this occurs, the DATA, DATA, CLOCK, and
CLOCK outputs switch to a constant dc output voltage
level of 1.3 V.
Pin 10
Pin 10 on the 1345-Type receiver is not an internally
connected (NIC) pin. This definition allows the 1345 to
be used in most customer 20-pin receiver module
applications. Customer’s printed-wiring boards that are
designed with ground, +5 V, –5 V, or no connection to
this pin are all acceptable options. For those applica-
tions that require monitoring the photocurrent of the
PIN photodetector for power monitoring purposes,
there are versions of the 1345 that require +5 V or –5 V
applied to Pin 10. Check Tables 3 and 4 for ordering
information.
Nonsquelched Data and Clock Outputs
Agere Systems also manufactures nonsquelching ver-
sions of the 1345 receiver for those applications that
require the data and clock outputs to continue to func-
tion after the link status flag is deactivated. In those
versions of the receiver, when the link status flag is
deactivated, a signal will continue to appear at the
DATA, DATA, CLOCK, and CLOCK outputs. See Table 4
for nonsquelching codes.
OPTIONAL V
PIN
5V
FLAG FLAG
DATA
DATA
FILTER
InGaAs
PIN
Si
PREAMPLIFIER
SILICON BIPOLAR
LIMITING AMPLIFIER
SILICON BIPOLAR
DECISION CIRCUIT
PLL TIMING
RECOVERY UNIT
CLOCK CLOCK
1-724(C)
Figure 1. Block Diagram
2
Agere Systems Inc.
AGERE [ AGERE SYSTEMS ]
