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Short Wavelength GBIC: HFBR-5601

Transmitter Section

The transmitter section consists

of an 850 nm VCSEL in an optical

subassembly (OSA), which mates

to the fiber cable. The VCSEL

OSA is driven by a custom, silicon

bipolar IC which converts

differential logic signals into an

analog Laser Diode drive current.

Receiver Section

The receiver includes a GaAs PIN

photodiode mounted together

with a custom, silicon bipolar

transimpedance preamplifier IC,

in an OSA. The OSA interfaces to

a custom silicon bipolar circuit

that provides post-amplification

and quantization. The post-

amplifier includes a Signal Detect

circuit that provides TTL

compatible logic-low output in

response to the detection of a

usable input optical signal.

Eye Safety Design

The laser driver is designed to be

Class 1 eye safe (CDRH21 CFR(J),

IEC 60825-1) under a single fault

condition. To be eye safe, only

one of two results can occur in

the event of a single fault. The

transmitter must either maintain

normal eye safe operation or the

transmitter should be disabled.

There are three key elements to

the safety circuitry: a monitor

diode, a window detector circuit,

and direct control of the laser

bias. The window detection circuit

monitors the average optical

power using the monitor diode. If

a fault occurs such that the dc

regulation circuit cannot maintain

the preset bias conditions within

±20%, the transmitter will

automatically be disabled. Once

this has occurred, an electrical

power reset will allow an

attempted turn-on of the

transmitter. TX_FAULT can also

be cleared by cycling TX_DISABLE

high for a time interval >10 µs.

Absolute Maximum Ratings

Stresses in excess of the absolute maximum ratings can cause catastrophic damage to the device. Limits apply to each parameter

in isolation, all other parameters having values within the recommended operating conditions. It should not be assumed that

limiting values of more than one parameter can be applied to the product at the same time. Exposure to the absolute maximum

ratings for extended periods can adversely affect device reliability.

Recommended Operating Conditions

Transceiver Electrical Characteristics

Notes:

2. See Figure 1 for measurement point.

4. Hot plug above actual steady state current.

Parameter

Symbol

Min.

Typ.

Max.

Unit

Notes

Storage Temperature

-40

+85

°C

Supply Voltage

-0.5

6.0

V

Data Input Voltage

TX_DAT

-0.5

1

Transmitter

Differential Input Voltage

±TX_DAT

2000

mV p-p

Relative Humidity

RH

5

95

%

Parameter

Symbol

Min.

Typ.

Max.

Unit

Notes

Ambient Operating Temperature

0+60

°C

Case Temperature

+75

°C

2

Supply Voltage

4.75

5.0

5.25

V

Supply Current

200

300

mA

3

Parameter

Symbol

Min.

Typ.

Max.

Unit

Notes

Surge Current

+30

mA

4

Power Dissipation

1.00

1.58

W

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