- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383642 > MT88E43B (Mitel Networks Corporation) Extended Voltage Calling Number Identification Circuit (ECNIC)(擴展電壓主叫識別電路（接收傳送的物理層信號）) PDF資料下載
參數(shù)資料
| 型號： | MT88E43B |
| 廠商： | Mitel Networks Corporation |
| 英文描述： | Extended Voltage Calling Number Identification Circuit (ECNIC)(擴展電壓主叫識別電路（接收傳送的物理層信號）) |
| 中文描述： | 擴展電壓主叫號碼識別電路（ECNIC）（擴展電壓主叫識別電路（接收傳送的物理層信號）） |
| 文件頁數(shù)： | 5/27頁 |
| 文件大小： | 180K |
| 代理商： | MT88E43B |
第1頁第2頁第3頁第4頁當前第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁
Preliminary Information
MT88E43B
57
ring voltage is applied to the TRIGin input. When the
voltage at TRIGin is above the Schmitt trigger high
going threshold V
T+
, TRIGRC is pulled low as C3
discharges. TRIGout stays low as long as the C3
voltage stays below the minimum V
T+
.
In a CPE designed for CND/CNAM, the TRIGout
high to low transition may be used to interrupt or
wake up the microcontroller. The controller can thus
be put into power down mode to conserve power.
If precise ring duration determination is critical,
capacitor C3 in Figure 3 may be removed. The
microcontroller will now be able to time the ring
duration directly. The result will be that TRIGout will
be low only as long as the ringing signal is present.
Previously the RC time constant would cause only
one interrupt.
Dual Tone Alert Signal Detection
The BT on hook (idle state) caller ID scheme uses a
dual tone alert signal whose characteristics are
shown in Table 1.
Table 1 also shows the Bellcore specifications for a
similar dual tone signal called CPE Alerting Signal
(CAS) for use in off-hook data transmission. For the
CIDCW service, the CAS must be detected in the
presence of near end speech. The CAS detector
must also be immune to imitation from near and far
end speech.
In the MT88E43B the dual tone signal is separated
into a high and a low tone by two bandpass filters. A
detection algorithm examines the two filter outputs to
determine the presence of a dual tone alert signal.
The ESt pin goes high when both tones are present.
Note that ESt is only a preliminary indication. The
indication must be sustained over the tone present
guard time to be considered valid. Tone present and
tone absent guard times can be implemented with
external RC components. The tone present guard
time rejects signals of insufficient duration. The tone
absent guard time masks momentary detection
dropout once the tone present guard time has been
satisfied. StD is the guard time qualified detector
output.
Dual Tone Detection Guard Time
When the dual tone signal is detected by the
MT88E43B, ESt goes high. When the signal ceases
to be detected, ESt goes low.
The ESt pin indicates raw detection of the dual tone
signal. Since the BT application requires a minimum
signal duration and the Bellcore application
requires protection from imitation by speech, ESt
detection must be guard time qualified. The StD pin
provides guard time qualified signal detection. When
the MT88E43B is used in a caller identity system,
StD indicates correct CAS/Tone Alert Signal
detection.
Figure 4 shows the relationship between the St/GT,
ESt and StD pins. It also shows the operation of the
guard time circuit.
The total recognition time is t
REC
= t
GP
+ t
DP
, where
t
GP
is the tone present guard time and t
DP
is the tone
a. The signal power is expressed in dBm referenced to 600 ohm
at the CPE A/B (tip/ring) interface.
b. ASL = active speech level expressed in dBm referenced to
600 ohm at the CPE tip/ring interface. The level is measured
according to method B of Recommendation P.56 "Objective
Measurement of Active Speech Level" published in the
CCITT Blue Book, volume V "Telephone Transmission
Quality" 1989.
EPL (Equivalent Peak Level) = ASL+11.7dB
c. SIN227 suggests that the recognition time should be not less
than 20ms if both tones are detected.
Item
BT
Bellcore
Low tone
frequency
2130Hz
±
1.1%
2130Hz
±
0.5%
High tone
frequency
2750Hz
±
1.1%
2750Hz
±
0.5%
Received
signal
level
-2 to -40dBV
per tone on-hook
(0.22 to -37.78dBm)
-14 to -32dBm
a
per tone off-hook
Signal
reject level
-46dBV
(-43.78dBm)
-45dBm
Signal
level
differential
(twist)
up to 7dB
up to 6dB
Unwanted
signals
<= -20dB
(300-3400Hz)
88ms to 110ms
c
<= -7dBm ASL
b
near end speech
Duration
75ms to 85ms
Speech
present
Table 1 - Dual Tone Alert Signal Characteristics
No
Yes
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MT88L85 | 3V Integrated DTMFTransceiver with Power Down & Adaptive Micro Interface |
| MT88L85AE | 3V Integrated DTMFTransceiver with Power Down & Adaptive Micro Interface |
| MT88L85AN | 3V Integrated DTMFTransceiver with Power Down & Adaptive Micro Interface |
| MT88L85AP | 3V Integrated DTMFTransceiver with Power Down & Adaptive Micro Interface |
| MT88L89 | 3V Integrated DTMFTransceiver with Adaptive Micro Interface |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MT88E43BE | 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:Extended Voltage Calling Number Identification Circuit 2 |
| MT88E43BS | 制造商:Microsemi Corporation 功能描述: |
| MT88E43BS1 | 制造商:Microsemi Corporation 功能描述:CALLER ID CMOS 3.58MHZ 3.3V/5V 24SOIC - Rail/Tube 制造商:Microsemi Corporation 功能描述:CALLING NUMBER ID CIRCUIT 2 |
| MT88E43BSR | 制造商:ZARLINK 制造商全稱:Zarlink Semiconductor Inc 功能描述:Extended Voltage Calling Number Identification Circuit 2 |
| MT88E43BSR1 | 制造商:Microsemi Corporation 功能描述:CALLER ID CMOS 3.58MHZ 3.3V/5V 24SOIC - Tape and Reel 制造商:Microsemi Corporation 功能描述:PB FREE CALLING NUMBER ID CIRCUIT 2 |
發(fā)布緊急采購，3分鐘左右您將得到回復。