mt88ebnr Zarlink Semiconductor, mt88ebnr Datasheet - Page 8

• Manufacturer Part Number: mt88ebnr
• Description: 4-wire Calling Number Identification Circuit 2 4-wire Cnic2 Semiconductor Inc
• Manufacturer: Zarlink Semiconductor

CAS Detection
In North America, CAS is used in off-hook signalling only. In Europe (ETSI) it is used in off-hook signalling, and by
BT in both on and off-hook signalling. ETSI calls it the Dual Tone Alerting Signal (DT-AS). Although the ETSI on-
hook standard contains a DT-AS specification, BT is the only administration known to employ CAS in on-hook
signalling. (BT calls it Tone Alert Signal.) The CAS/DT-AS characteristics are summarized in Table 3.
Frequency Tolerance
Signal Level (per tone)
Reject Level (per tone)
Maximum Twist (V
CAS/DT-AS Characteristics
2130 Hz and 2750 Hz
2130Hz
/V
2750Hz
Differential Input Amplifier
Voltage Gain
(A
C1 = C2
R1 = R4 (For unity gain R5= R4)
R3 = (R2R5) / (R2 + R5)
Input Impedance
(Z
)
Voltage Gain
(A
Highpass Corner Frequency
f
-3dB
V
IN
Figure 3 - Single Ended Input Configuration
V
diff) = R5/R1
diff) = 2
) = R
Figure 4 - Differential Input Configuration
= 1/(2 R
C
C1
C2
F
(Off-hook only)
-14 to -32 dBm
/ R
Bellcore
IN
-45 dBm
+/-0.5%
R1
IN
+/-6 dB
R1
R4
R
C)
2
Zarlink Semiconductor Inc.
IN
+ (1/ C)
R3
MT88E45
a
2
d
Highpass Corner Frequency
8
f
-3dB
R2
R5
R
= 1/(2 R1C1)
F
-9.78 to -32.78 dBm
(-12 to -35 dBV
(Off-hook)
IN+
IN-
GS
V
+/-0.5%
GS
+/-6 dB
IN+
V
REF
IN-
ETSI
REF
b
e
)
(Off-hook = ‘Loop State’)
(On-hook = ‘Idle State’)
On-hook: -43.78 dBm
+0.22 to -37.78 dBm
Off-hook: +/-0.6%
On-hook: +/-1.1%
(-2 to -40 dBV)
(-46 dBV)
+/-7 dB
BT
c
Data Sheet