HFCT-5942 HP [Agilent(Hewlett-Packard)], HFCT-5942 Datasheet - Page 8

• Manufacturer Part Number: HFCT-5942
• Description: Single Mode Laser Small Form Factor Transceivers for ATM, SONET OC-48/SDH STM-16 Part of the Agilent METRAK family
• Manufacturer: HP [Agilent(Hewlett-Packard)]

DIMENSIONS IN MILLIMETERS (INCHES)
NOTES:
1. THIS FIGURE DESCRIBES THE RECOMMENDED CIRCUIT BOARD LAYOUT FOR THE SFF TRANSCEIVER.
2. THE HATCHED AREAS ARE KEEP-OUT AREAS RESERVED FOR HOUSING STANDOFFS. NO METAL TRACES OR
3. 2 x 10 TRANSCEIVER MODULE REQUIRES 26 PCB HOLES (20 I/O PINS, 2 SOLDER POSTS AND 4 PACKAGE
4. THE MOUNTING STUDS SHOULD BE SOLDERED TO CHASSIS GROUND FOR MECHANICAL INTEGRITY AND TO
5. HOLES FOR HOUSING LEADS MUST BE TIED TO SIGNAL GROUND.
(0.299)
The HFCT-5942xxx has a
transmit disable function which
is a single-ended +3.3 V TTL
input which is dc-coupled to
pin 13. In addition the devices
offer the designer the option
of monitoring the laser diode
bias current and the laser
diode optical power. The
voltage measured between pins
17 and 18 is proportional to
the bias current through an
internal 10 Ω resistor.
Similarly the optical power
rear facet monitor circuit
provides a photo current
which is proportional to the
voltage measured between pins
19 and 20, this voltage is
measured across an internal
200 Ω resistor.
(0.525)
Figure 7. Recommended Board Layout Hole Pattern
8
13.34
7.59
GROUND CONNECTION IN KEEP-OUT AREAS.
GROUNDING TABS).
PACKAGE GROUNDING TABS SHOULD BE CONNECTED TO SIGNAL GROUND.
ENSURE FOOTPRINT COMPATIBILITY WITH OTHER SFF TRANSCEIVERS.
2 x Ø 2.29 MAX.
(0.118)
3
(0.09)
(0.055 ±0.004)
2 x Ø 1.4 ±0.1
(0.236)
(0.118)
6
3
(0.28)
7.11
(0.35)
8.89
(0.18)
4.57
(0.055 ±0.004)
2 x Ø 1.4 ±0.1
9 x 1.78
(0.07)
The receiver section is
internally ac-coupled between
the preamplifier and the post-
amplifier stages. The Data and
Data-bar outputs of the post-
amplifier are internally biased
and ac-coupled to their
respective output pins (pins 9,
10).
ended, +3.3 V TTL compatible
output signal that is dc-
coupled to pin 8 of the
module. Signal Detect should
not be ac-coupled externally to
the follow-on circuits because
of its infrequent state changes.
(0.63)
Signal Detect is a single-
16
(0.121)
3.08
(0.079)
(0.14)
3.56
2
10.16
(0.4)
(0.378)
20 x Ø 0.81 ±0.1
9.59
(0.032 ±0.004)
2 x Ø 2.29
(0.09)
(0.079)
2
(0.055 ±0.004)
4 x Ø 1.4 ±0.1
The designer also has the option
of monitoring the PIN photo
detector bias current. Figure 6
shows a resistor network,
which could be used to do this.
Note that the photo detector
bias current pin must be
connected to V
recommends that a decoupling
capacitor is used on this pin.
Caution should be taken to
account for the proper
intercon-nection between the
supporting Physical Layer
integrated circuits and these
transceivers. Figure 6
illustrates a recommended
interface circuit for
interconnecting to a +3.3 V dc
PECL fiber-optic transceiver.
CC
. Agilent also