AK2500B Datasheet, PDF (8/17 Pages) Asahi Kasei Microsystems – DS3/STS-1 Analog Line Receiver

ASAHI KASEI
[AK2500B]
Loss of Signal
This device detects the loss of signal by analog and digital methods. RLOS goes high if either the analog or digital
loss has detected.
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 6, output pins status is as follows.
RLOS : High
RPDATA: Low
RNDATA: Low
RCLK : Recovered from EXCLK
Table 6. Analog Loss-of-Signal thresholds
LOSTHR
Clear Alarm Level
Set Alarm Level
Voltage
Min. Upper Max. Upper Min. Lower Max. Lower
Threshold Threshold Threshold Threshold
GND
71
125
59
105
VDD/2
56
99
47
83
VDD
45
79
37
66
Notes:
- Set Alarm Level is 0.5dB lower than Clear Alarm Level
- Measured with PN20 pattern, 450ft cable loss, flat loss
Units
mV
mV
mV
MS0005-E-00
-8-
1999/12