MT8885AE1 参数 Datasheet PDF下载

MT8885

2.0

Call Progress Filter

Data Sheet

A call progress mode, using the MT8885, 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.

EVENTS

A

B

C

D

E

F

t

REC

V

in

t

REC

TONE #n

t

ID

TONE

#n + 1

t

DO

TONE

#n + 1

t

DP

ESt

t

DA

t

GTP

t

GTA

V

TSt

St/GT

t

PStRX

RX

0

-RX

3

DECODED TONE # (n-1)

#n

# (n + 1)

t

PStb3

b3

b2

Read

Status

Register

IRQ/CP

Figure 7 - Receiver Timing Diagram

LEVEL

(dBm)

-25

0

= Reject

= May Accept

= Accept

250

500

750

FREQUENCY (Hz)

Figure 8 - Call Progress Response

8

Zarlink Semiconductor Inc.