AK2305 Datasheet, PDF (33/43 Pages) Asahi Kasei Microsystems – Dual PCM CODEC for ISDN TERMINAL ADAPTER

ASAHI KASEI
[AK2305]
Parameters
Condition
Typ
Units _s
t
5
14
Tone Absent Detection Time
DA
4
ms
t
48
-
Tone Duration Reject(*1)
R
-
37
Interdigit Pause Accept(*1)
ID
-
ms
tO
-
ms
t DTOE=5V,unloaded
-
us
t
DTOE=5V,unloaded
-
us
t
DTOE=5V,unloaded
-
us
t
R =10k, C =50pF
40
Output Data Disable(DTOE to DTO)
PTD
L
L
10
ns
GTPn,
(n=0-3) are default. Adjustable by setting
GPAn
See p.19 & p.20.
DTINx
Internal
Counter
t_GTP ,t_GTA
DTOxx
STDx
DTOE
t_REJ
t_REC
t_ID
TONE #n+1
t_DP
TONE #n
t_DA
t_DO
RegisterGTP
t_GTP
t_GTA
RegisterGTA
t_PQ
DECODED TONE #n-1
t_PSTD
DECODED TONE #n
t_QSTD
t_PTD
Hi-Z
DECODED TONE #n+1
t_PTE
Figure 1 : DTMF Receiver Timing
33
1999/8