JSF-21S0AA1

JSG-21S1AA1

JSF-21S2AA1

JSG-21S3AA1

SW 2x / 1x Fibre Channel Small Form Factor PTH Transceiver

Page 6 of 22

03/06/02

Operation

Resetting a Laser Fault

Resetting a laser fault by toggling the Tx_Disable input will permit the SFF-PTH-SW-2X5/2X6 to attempt to

power on the laser following a fault condition. Continuous resetting and re-powering of the laser under a hard

fault condition could cause a series of optical pulses with sufficient energy to violate laser safety standards.

To alleviate the possibility of violating laser safety standards, the SFF-PTH-SW-2X5/2X6 will turn off the laser

if a second fault is detected within 25 ms of the laser powering on. This lock is cleared during each power on

cycle. Please refer to the timing diagrams below.

Initialization Timings

SFF-PTH-2125-SW-2X5/2X6

with Tx_Disable De-asserted

t_init

< 300ms

Vcc > 3.15V

Tx_Disable

Optical Transmit

Signal

1

0

Tx_Fault

Tx_Fault option is only available on 2 X 6

with Tx_Disable Asserted

t_init < 300ms

Vcc > 3.15V

Tx_Disable

Optical Transmit

Signal

Tx_Fault

Tx_Fault option is only available on 2 X 6

SFF-PTH-2125-SW-2X5/2X6

Occurrence

Optical

Power

t_reset

>10

µs

Tx_Disable

t_init*

<300ms

*only if the fault is transient

t_reset

>10

µs

t_init*

<300ms

*only if the fault is transient

t_fault

of transmitter

safety fault

Occurrence

Optical

Power

Tx_Disable

of transmitter

safety fault

<100

µs

Unsuccessful Recovery from a

Transmitter Safety Fault

Successful Recovery from a

Transmitter Safety Fault

Tx_Fault option is only available on 2 X 6

Tx_Fault option is only available on 2 X 6

Tx_Fault

Tx_Fault