166

HFBR-5527

125 MBd Data Link

Data link operating conditions

and performance are specified for

the transmitter and receiver in

the recommended applications

circuits shown in Figure 1. This

circuit has been optimized for

125 MBd operation. The

Applications Engineering

Department in the Hewlett-

Recommended Operating Conditions for the Circuits in Figures 1 and 2.

Parameter

Symbol

Min.

Max.

Unit

Note

Ambient Temperature

070

°C

Supply Voltage

+4.75

+5.25

V

Data Input Voltage - Low

V

Data Input Voltage - High

V

Data Output Load

45

55

Ω

1

Signaling Rate

1

125

MBd

Duty Cycle

D.C.

40

60

%

2

recommended transmit and receive application circuits.

Parameter

Symbol

Max.

Unit

Condition

Note

Optical Power Budget, 1 m POF

11

16

dB

5, 6, 7

Optical Power Margin,

3

6

dB

5, 6, 7

20 m Standard POF

Link Distance with

1

20

27

m

Standard 1 mm POF

Optical Power Margin,

3

6

dB

5, 6, 7

25 m Low Loss POF

Link Distance with Extra

1

25

32

m

Low Loss 1 mm POF

Optical Power Budget, 1 m HCS

12

dB

5, 6, 7

Optical Power Margin, 100 m HCS

6

dB

5, 6, 7

Link Distance with HCS cable

1

125

m

Notes:

1. If the output of U4C in Figure 1, page 4 is transmitted via coaxial cable, terminate with a 50

2. Run length limited code with maximum run length of 10

µs.

3. Minimum link performance is projected based on the worst case specifications of the transmitter, receiver, and POF cable, and the

typical performance of other components (e.g., logic gates, transistors, resistors, capacitors, quantizer, HCS cable).

4. Typical performance is at 25

°C, 125 MBd, and is measured with typical values of all circuit components.

5. Standard cable is HFBR-RXXYYY plastic optical fiber, with a maximum attenuation of 0.24 dB/m at 650 nm and NA = 0.5.

Extra low loss cable is HFBR-EXXYYY plastic optical fiber, with a maximum attenuation of 0.19 dB/m at 650 nm and NA = 0.5.

HCS cable is HFBR-H/VXXYYY glass optical fiber, with a maximum attenuation of 10 dB/km at 650 nm and NA = 0.37.

6. Optical Power Budget is the difference between the transmitter output power and the receiver sensitivity, measured after

1 meter of fiber. The minimum OPB is based on the limits of optical component performance over temperature, process, and

recommended power supply variation.

7. The Optical Power Margin is the available OPB after including the effects of attenuation and modal dispersion for the minimum

link distance: OPM = OPB - (attenuation power loss + modal dispersion power penalty). The minimum OPM is the margin

available for long term LED LOP degradation and additional fixed passive losses (such as in-line connectors) in addition to the

minimum specified distance.

Packard Optical Communication

Division is available to assist in

optimizing link performance for

higher or lower speed operation.