HFBR-0410 Avago Technologies US Inc., HFBR-0410 Datasheet - Page 10

• Manufacturer Part Number: HFBR-0410
• Description: KIT EVAL FIBER OPTIC 5MBD
• Manufacturer: Avago Technologies US Inc.

Specifications of HFBR-0410

• Main Purpose: Interface, Fiber Optics
• Embedded: No
• Utilized Ic / Part: HFBR-1412, HFBR-2412
• Primary Attributes: DC ~ 5MBd TTL
• Secondary Attributes: ST Connectors
• Silicon Core Number: HFBR-1412, HFBR-2412
• Kit Contents: TX/RX Mods, Cable, Pol Kit, SW, Pwr. Sup
• Silicon Family Name: HFBR-0400
• Features: Dc To 5 MBd TTL Compatible Fiber Optic Component
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 516-2138; HFBR-0410

5 MBd Logic Link Design
If resistor R
70.4 , a forward current I
48 mA is applied to the HFBR-
14X4 LED transmitter. With I
48 mA the HFBR-14X4/24X2
logic link is guaranteed to work
with 62.5/125 m fiber optic
cable over the entire range of 0
to 1750 meters at a data rate of
dc to 5 MBd, with arbitrary data
format and pulse width distortion
typically less than 25%. By
setting R
ter can be driven with I
if it is desired to economize on
power or achieve lower pulse
distortion.
Figure 2. Typical circuit configuration.
10
1
= 115
1
in Figure 2 is
, the transmit-
F
= 30 mA,
F
of
F
=
The following example will illus-
trate the technique for selecting
the appropriate value of I
Maximum distance required
= 400 meters. From Figure 3 the
drive current should be 15 mA.
From the transmitter data
V
as shown in Figure 9.
R
R
F
1
1
= 1.5 V (max.) at I
= ––––––– = –––––––––
= 233
V
CC
I
F
- V
F
5 V - 1.5 V
15 mA
F
= 15 mA
F
and R
1
.
The curves in Figures 3, 4, and 5
are constructed assuming no in-
line splice or any additional
system loss. Should the link
consists of any in-line splices,
these curves can still be used to
calculate link limits provided they
are shifted by the additional
system loss expressed in dB. For
example, Figure 3 indicates that
with 48 mA of transmitter drive
current, a 1.75 km link distance
is achievable with 62.5/125 m
fiber which has a maximum
attenuation of 4 dB/km. With
2 dB of additional system loss, a
1.25 km link distance is still
achievable.