AK2504A Datasheet, PDF (21/30 Pages) List of Unclassifed Manufacturers – DS3/STS-1/ES Transceiver

ASAHI KASEI
[AK2504A]
Loss of Signal
E3
AK2504A detects the loss of signal by analog and digital methods. Loss of Signal function in E3 mode is as
follows.
- Analog loss detector monitors the peak level of the incoming signal.
- If the peak level falls below Set Alarm Threshold Level as shown in Table 15, DLOS circuit starts counting
the number of the incoming data bits as described in the following section “DLOS”.
- If DLOS circuit detects consecutive 128±5 bits of the incoming data lower than Set Alarm Threshold Level,
AK2504A alarms Loss of Signal by setting RLOS high. Other output pins status is as shown in the diagram
below.
- RLOS is set low if 32±5 bits of the incoming data higher than Clear Alarm Threshold Level are detected.
Normal Operation
RCLK : Recovered from RIN input
RPDATA : Recovered data
RNDATA : Recovered data
RLOS : Low
Peak level of Set Alarm
the incoming _< Threshold
data
Level
for 128 +/- 5 consecutive bits
of the incoming data
Peak level of Set Alarm
the incoming _> Threshold
data
Level
for 32 +/- 5 bits
of the incoming data
LOS
RCLK : Recovered from EXCLK
RPDATA : Low
RNDATA : Low
RLOS : High
Fig. 10 Loss of Signal state diagram (E3)
MS0143-E-01
- 21 -
2004/01