MT88E45
Advance Information
Line Reversal
‘Idle State Tone Alert Signal’
DT-AS
Ch. seizure
D
Mark
E
Data
F
Ring
A/B Wires
A
B
C
G
Note 4
PWDN
Note 6
50-150ms
Tip/Ring
CASen
Note 6
t
DP
t
DA
EST
t
t
GA
GP
Note 1
Note 2
V
ST/GT
TGt
t
t
Note 3
ABS
REC
STD
Note 7
15 1ms
< 0.5mA (optional)
TE DC load
TE AC load
<120µAµ
20 5ms
Current wetting pulse (see SIN227)
Zss (Refer to SIN227)
Note 4
Note 5
FSKen
Note 6
t
t
CA
CP
A ≥ 100ms
CD
B = 88-110ms
DR
C ≥ 45ms (up to 5sec)
D = 80-262ms
E = 45-75ms
Note 7
DCLK
DATA
OSC2
F ≤ 2.5sec (typ. 500ms)
G > 200ms
..101010..
Data
t
Note:
All
values
t
PU
PD
obtained from SIN227
Issue 1
Figure 17 - Application Timing for BT Caller Display Service (CDS), e.g., CLIP
Notes:
1) The total recognition time is t
= t + t
where t is the tone present guard time and t is the tone present detect time. V
GP DP
REC
GP
DP ,
TGt
TGt
is the comparator threshold (refer to Figure 5 for details).
2) The total tone absent time is t = t + t where t is the tone absent guard time and t is the tone absent detect time. V
ABS
GA
DA ,
GA
DA
is the comparator threshold (refer to Figure 5 for details).
3) By choosing t =15ms, t
will be 15-25ms so that the current wetting pulse and AC load can be applied right after the STD rising
GA
ABS
edge.
4) SIN227 specifies that the AC and DC loads should be removed between 50-150ms after the end of the FSK signal, indicated by CD
returning to high. The MT88E45 may also be powered down at this time.
5) The MT88E45 should be taken out of FSK mode when FSK is not expected to prevent the FSK demodulator from reacting to other
in-band signals such as speech, DT-AS/CAS and DTMF tones.
6) PWDN, Tip/Ring CASen, FSKen are internal signals decoded from CB0/1/2.
7) This signal represents the mode of the DR/STD pin.
24
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
