參數(shù)資料
型號(hào)： MT88L85
廠商： Mitel Networks Corporation
英文描述： 3V Integrated DTMF Transceiver with Power-Down and Adaptive Micro Interface(3V 集成雙音多頻信號(hào)（DTMF）接收器（帶電源關(guān)閉和自適應(yīng)微接口）)
中文描述： 3V的集成雙音多頻收發(fā)器關(guān)閉電源和自適應(yīng)微型接口（3V的集成雙音多頻信號(hào)（DTMF）的接收器（帶電源關(guān)閉和自適應(yīng)微接口））
文件頁(yè)數(shù)： 6/25頁(yè)
文件大?。?/td> 197K
代理商： MT88L85
MT88L85
4-76
Figure 8 - Description of Timing Events
EXPLANATION OF EVENTS
A)
TONE BURSTS DETECTED, TONE DURATION INVALID, RX DATA REGISTER NOT UPDATED.
B)
TONE #n DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN RX DATA REGISTER.
C)
END OF TONE #n DETECTED, TONE ABSENT DURATION VALID, INFORMATION IN RX DATA REGISTER
RETAINED UNTIL NEXT VALID TONE PAIR.
D)
TONE #n+1 DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN RX DATA REGISTER.
E)
ACCEPTABLE DROPOUT OF TONE #n+1, TONE ABSENT DURATION INVALID, DATA REMAINS UNCHANGED.
F)
END OF TONE #n+1 DETECTED, TONE ABSENT DURATION VALID, INFORMATION IN RX DATA REGISTER
RETAINED UNTIL NEXT VALID TONE PAIR.
EXPLANATION OF SYMBOLS
V
in
DTMF COMPOSITE INPUT SIGNAL.
ESt
EARLY STEERING OUTPUT. INDICATES DETECTION OF VALID TONE FREQUENCIES.
St/GT
STEERING INPUT/GUARD TIME OUTPUT. DRIVES EXTERNAL RC TIMING CIRCUIT.
RX
0
-RX
3
4-BIT DECODED DATA IN RECEIVE DATA REGISTER
b3
DELAYED STEERING IN STATUS REGISTER (BIT 3) INDICATES THAT VALID FREQUENCIES HAVE BEEN
PRESENT/ABSENT FOR THE REQUIRED GUARD TIME THUS CONSTITUTING A VALID SIGNAL. ACTIVE LOW
FOR THE DURATION OF A VALID DTMF SIGNAL.
b2
RECEIVE DATA REGISTER FULL (BIT 2) IN STATUS REGISTER INDICATES THAT VALID DATA IS IN THE
RECEIVE DATA REGISTER. THE BIT IS CLEARED AFTER THE STATUS REGISTER IS READ.
IRQ/CP
INTERRUPT IS ACTIVE INDICATING THAT NEW DATA IS IN THE RX DATA REGISTER. THE INTERRUPT IS
CLEARED AFTER THE STATUS REGISTER IS READ.
t
REC
MAXIMUM DTMF SIGNAL DURATION NOT DETECTED AS VALID. TYPICALLY 20MS.
t
REC
MINIMUM DTMF SIGNAL DURATION REQUIRED FOR VALID RECOGNITION. TYPICALLY 40MS.
t
ID
MINIMUM TIME BETWEEN VALID SEQUENTIAL DTMF SIGNALS. TYPICALLY 40MS.
t
DO
MAXIMUM ALLOWABLE DROPOUT DURING VALID DTMF SIGNAL. TYPICALLY 20MS.
t
DP
TIME TO DETECT VALID FREQUENCIES PRESENT.
t
DA
TIME TO DETECT VALID FREQUENCIES ABSENT.
t
GTP
GUARD TIME, TONE PRESENT.
t
GTA
GUARD TIME, TONE ABSENT.
applications, leaving R1 to be selected by the
designer. Different steering arrangements may be
used to select independent tone present (t
GTP
) and
tone absent (t
GTA
) guard times. This may be
necessary to meet system specifications which place
both accept and reject limits on tone duration and
interdigital pause. Guard time adjustment also allows
the designer to tailor system parameters such as
talk-off and noise immunity.
Increasing t
REC
improves talk-off performance since
it reduces the probability that tones simulated by
speech will maintain a valid signal condition long
enough to be registered. Alternatively, a relatively
short t
REC
with a long t
DO
would be appropriate for
extremely noisy environments where fast acquisition
time and immunity to tone drop-outs are required.
Design information for guard time adjustment is
shown in Figure 6. The receiver timing is shown in
Figure 7 with a description of the events in Figure 8.
Call Progress Filter
A call progress mode, using the MT88L85, can be
selected to allow the detection of various tones,
which identify the progress of a telephone call on the
network. The call progress tone input and DTMF
input are common, however, call progress tones can
only be detected when CP mode has been selected.
DTMF signals cannot be detected if CP mode has
been selected (see Table 7). Figure 10 indicates the
useful detect bandwidth of the call progress filter.
Frequencies presented to the input, which are within
the ‘a(chǎn)ccept’ bandwidth limits of the filter, are hard-
limited by a high gain comparator with the IRQ/CP
pin serving as the output. The square-wave output
obtained from the schmitt trigger can be analyzed by
a microprocessor or counter arrangement to
determine the nature of the call progress tone being
detected. Frequencies which are in the ‘reject’ area
will not be detected and consequently the IRQ/CP
pin will remain low.
DTMF Generator
The DTMF transmitter employed in the MT88L85 is
capable of generating all sixteen standard DTMF
tone pairs with low distortion and high accuracy. All
frequencies are derived from an external 3.579545
MHz crystal. The sinusoidal waveforms for the
individual tones are digitally synthesized by using
row and column programmable dividers and
switched capacitor D/A converters. The row and
column tones are mixed and filtered to provide a
DTMF signal with low total harmonic distortion and
相關(guān)PDF資料
PDF描述
MT88L89 3V Integrated DTMF Transceiver with Adaptive Micro Interface(3V 集成雙音多頻信號(hào)（DTMF）接收器（帶自適應(yīng)微接口）)
MT88V32 8 x 4 High Performance Video Switch Array(8 x 4 高性能數(shù)字可編程正交開關(guān)（用于控制寬帶視頻信號(hào)）)
MT8910-1 CMOS ST-BUS⑩ FAMILY Digital Subscriber Line Interface Circuit
MT8910-1AC CMOS ST-BUS⑩ FAMILY Digital Subscriber Line Interface Circuit
MT8910-1AP CMOS ST-BUS⑩ FAMILY Digital Subscriber Line Interface Circuit
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MT88L85AE 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:3V Integrated DTMFTransceiver with Power Down & Adaptive Micro Interface
MT88L85AE1 制造商:Microsemi Corporation 功能描述:DTMF TXRX 3.58MHZ CMOS 3V 24PDIP - Rail/Tube 制造商:MICROSEMI CONSUMER MEDICAL PRODUCT GROUP 功能描述:IC TXRX DTMF 3V 24PDIP 制造商:Microsemi Corporation 功能描述:IC TXRX DTMF 3V 24PDIP
MT88L85AN 制造商:Microsemi Corporation 功能描述:
MT88L85AN1 制造商:Microsemi Corporation 功能描述:DTMF TXRX 3.58MHZ CMOS 3V 24SSOP - Rail/Tube 制造商:Microsemi Corporation 功能描述:3V DTMF TRANSCEIVER
MT88L85ANR 制造商:Microsemi Corporation 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*