HFBR-5527 Agilent(Hewlett-Packard), HFBR-5527 Datasheet - Page 10

• Manufacturer Part Number: HFBR-5527
• Description: 125 Megabaud Fiber Optic Transceiver JIS FO7 Connection
• Manufacturer: Agilent(Hewlett-Packard)

174
The HFBR-5527 is typically used
to construct 125 MBd digital
fiber-optic receivers which use
the same +5 volt power supply
that powers the host system’s
microprocessors, CMOS logic, or
TTL logic. To build a digital
receiver, the analog HFBR-5527
component must be connected to
a post amplifier and a compara-
tor. This post amplifier plus
comparator function is commonly
known as a quantizer. The 0 V
common and +5 V power supply
connections for the HFBR-5527
and quantizer must be isolated
from the host system’s power and
ground planes by a low pass
filter. This recommended low pass
Figure 9. Recommended Power Supply Filter Circuit.
0.1 µF
V
CC
9
RECEIVER
4.7
10
4.7
2.3
4
0.47 µF
1
filter assures that the electrical
noise normally present in the
host system’s digital logic power
supply will not reduce the
sensitivity of fiber-optic receivers
implemented with the
HFBR-5527. The quantizer and
power supply filter circuits
recommended for use with the
HFBR-5527 are shown in
Figure 7 of HP Application
Note 1066. For optimum
performance, the HFBR-5527
should be used with the same
quantizer and power supply
filters recommended for use with
HP’s HFBR-15X7 and
HFBR-25X6 components. To
maximize immunity to electrical
RX
ANALOG
OUTPUT
noise, pins 3, 9, and 10 of the
HFBR-5527 should be connected
to filtered receiver common. For
best common mode noise
rejection, the connections
between pins 1 and 2 of the
HFBR-5527 and the quantizer’s
differential input should be of
equal length, and the components
in both traces should be placed to
achieve symmetry. The preceding
recommendations minimize the
cross talk between the fiber-optic
transmitter and receiver. These
recommendations also improve
the fiber-optic receiver’s
immunity to environmental noise
and the host system’s electrical
noise.