W925E625 Datasheet, PDF (73/75 Pages) Winbond – 8-bit CID MICROCONTROLLER

W925E/C625
DTMF Decoder
PARAMETER
SYM. MIN. TYP
INPUT SENSITIVITY PER TONE
-29
Positive and negative twist accept
7
Frequency Deviation accept
1.5
Frequency Deviation reject
3.5
3^rd Tone Tolerance
Noise Tolerance
Dial tone Tolerance
22
Notes:
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.
MAX.
1
-16
-12
UNITS NOTES
dBm 1,2
Db 1,2
% 1,2
% 1,2
Db 1,2,3
Db 1,2,3
Db 1,2,4
DTMF Detection Interface
PARAMETER
CONDITION SYM. MIN. TYP^‡ MAX. UNITS NOTES
DTMF present detect time
DTMF absent detect time
Est
t_FP
0.5
t_FA
0.1
DTMF Detected Duration
DTMFD = 1 t_DD
40
DTMF Signal Ignore Time
DTMFD = 0
t_DI
DTMF Pause Accept Time
DTMFD = 1 t_DPA
20
8
MS
8
MS
MS
20
MS
MS
“‡” Typical figure are at V_DD = 5V and temperature = 25 ℃ are design aids only, not guaranteed and not subject to production
testing.
- 73 -
Publication Release Date: July 4, 2005
Revision A10