AK2504A Datasheet, PDF (19/30 Pages) List of Unclassifed Manufacturers – DS3/STS-1/ES Transceiver

ASAHI KASEI
[AK2504A]
Loss of Signal
DS3/STS-1
AK2504A detects the loss of signal by analog and digital methods. Loss of Signal function in DS3/STS-1 mode is
as follows.
Analog Loss of Signal(ALOS)
Analog loss detector operates as follows.
- Analog loss detector monitors the peak level of the incoming signal.
- If the peak level falls below Alarm set threshold as shown in Table 14, output pins status is shown in the
diagram below.
Table 14 Analog Loss-of-Signal thresholds (DS3/STS-1/E3)
LOSTHR
Voltage
Clear Alarm Level
Min. Upper Max. Upper
Threshold Threshold
Set Alarm Level
Min. Lower Max. Lower
Threshold Threshold
Units
VSS
80
160
70
150
mVpk
VDD
50
110
40
Notes:
- Set Alarm Level is 0.5dB lower than Clear Alarm Level.
100
mVpk
Digital Loss of Signal(DLOS)
Digital loss detector operates as follows.
- A digital loss detector monitors consecutive 0s and 1s density in recovered data.
- RLOS is set high if 175±5 consecutive 0s is detected.
- RPDATA,RNDATA are set low if ALOS is detected.
- RLOS is set low if 33% 1s density (58 1s in 175 consecutive bits) and no consecutive 100 0s are detected.
MS0143-E-01
- 19 -
2004/01