
W925E/C625
8-bit CID Microcontroller
FSK Detection Interface
Parameter
Input Frequency Detection
Bell 202 Mark (logic 1)
Bell 202 Space (logic 0)
ITU-T V.23 Mark (logic 1)
ITU-T V.23 Space (logic 0)
Maximum Input Signal Level
Input Sensitivity
Transmission Rate
Input Noise Tolerance
Notes:
1. Both mark and space have the same amplitude. Both mark and space are at the nominal frequencies.
2. Band limited random noise 300 - 3400 Hz. Present only when FSK signal is present.
3. These characteristics are at VDD = 5V and temperature = 25
¢ J
.
FSK Detection
Parameter
Condition Symbol
FSK detection enable time
FSKE
Input FSK to FCD high delay
Input FSK to FCD low delay
Data Ready ACK Time
FDR
Rate
Input FSK to DATA delay
Frequency
High Time
Low Time
DCLK to FDR delay
DCLK, FDR
Note :
1. FSK input data rate at 1200 +/- 12 baud.
2. OSCI frequency at 3.579545 MHz +/- 0.1%.
"
" Typical figure are at V
DD
= 5V and temperature = 25
¢ J
are design aids only, not guaranteed and not subject to
production testing.
DTMF Decoder
Parameter
Symbol Min
Input Sensitivity per tone
Positive and negative twist accept
Frequency Deviation accept
Frequency Deviation reject
3rd Tone Tolerance
Noise Tolerance
Dial tone Tolerance
Note :
1. signal consists of all DTMF tones.
2. Tone duration is 40mS at least, tone pause duration is 40mS at least.
3. Referenced to the lowest level frequency component in DTMF signal.
4. Referenced to the minimum valid accept level.
Revision : A6
-68-
Release Date : 2002/7/2
Symbol
f
Mark
f
Space
f
Mark
f
Space
SNR
TONE
20
Min
1188
2178
1280.5
2068.5
-43
1188
Typ
1200
2200
1300
2100
1200
Max
1212
2222
1319.5
2131.5
-5.78
1212
Units Notes
+/- 1 %
+/- 1 %
+/- 1.5 %
+/- 1.5 %
dBm
dBm 1, 3
baud
dB
1, 2
Hz
Min
8
415
1188
1201.6 1202.8
415
415
415
Typ
416
1200
1
Max
25
25
417
1212
5
1204
417
417
417
Units Notes
MS
MS
MS
US
BpS 1
MS
Hz
US
US
US
t
FSK
t
CP
t
CA
t
DR
t
IDD
f
DCLK
t
CH
t
CL
t
CRD
FCD
2
DATA
2
2
2
2
416
416
416
DCLK
Typ
Max
Units
dBm 1,2
dB
%
%
dB
dB
dB
Notes
-29
7
1.5
3.5
1
1,2
1,2
1,2
1,2,3
1,2,3
1,2,4
-16
-12
22