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5 ELECTRICAL CHARACTERISTICS
5.5 Crystal Oscillation Characteristics
Unless otherwise noted: V
Parameter
Oscillation start time
5.6 FSK Demodulation Circuit Characteristics
5.6.1 FSK AC Characteristics
Unless otherwise noted: V
Parameter
Transfer rate
Bell 202 mark (logic 1) frequency
Bell 202 space (logic 0) frequency
ITU-T V.23 mark (logic 1) frequency
ITU-T V.23 space (logic 0) frequency f
SN ratio
Carrier-detect ON sensitivity ∗1
(input level at TPI/RING)
Carrier-detect OFF sensitivity ∗1
∗1 When the gain in the input amp is set to G
from the equation below.
CD
[dBm] = -G
ONFSK
CD
[dBm] = -G
OFFFSK
5.6.2 FSK Switching Characteristics
Unless otherwise noted: V
Parameter
PDWN fall → FSK
Carrier detect start time
Data end → #DET rise
PDWN rise → Oscillation start
#RDRC
#RDET
PDWN
20
=2.7V to 5.5V, V
=0V, C
DD
SS
Symbol
t
sta
3.579545Mhz oscillator
=5.0/3.0V, V
=0V, f
DD
SS
CLK
Symbol
T
RATE
f
B1
f
B0
f
V1
V2
SNR
CD
V
ONFSK
Input amp gain (G
V
Input amp gain (G
CD
V
OFFFSK
Input amp gain (G
V
Input amp gain (G
(dB), the CD
AMP
- 48.0 + 20log( V
DD
) [dBm],
AMP
5
- 50.0 + 20log( V
DD
) [dBm],
AMP
5
=5.0/3.0V, V
=0V, f
DD
SS
CLK
Symbol
t
SUPD
t
CDON
t
CDOFF
t
V
DOCH
V
1st RING
Input
#DET
SDO
OSC4
Figure 5.6.1 FSK switching characteristics
=C
=18pF, Ta=25°C
G
D
Condition
=3.579545MHz, Ta=-20 to 70°C
Condition
=5V
DD
)=-5dB
AMP
=3V
DD
)=-9.4dB
AMP
=5V
DD
)=-5dB
AMP
=3V
DD
)=-9.4dB
AMP
and CD
ONFSK
OFFFSK
CD
[dBV] = -G
ONFSK
CD
[dBV] = -G
OFFFSK
=3.579545MHz, Ta=-20 to 70°C, C
Condition
=5V
DD
=3V
DD
101010...
1
DATA
V
IH2
V
IL2
t
SUPD
t
t
CDON
CDOFF
101010...
1
DATA
t
DOCH
EPSON
Min.
Typ.
Max.
20
Min.
Typ.
Max.
1188
1200
1212
1188
1200
1212
2178
2200
2222
1280
1300
1320
2068
2100
2132
20
–
–
-45.0
-43.0
-41.0
-47.2
-45.2
-43.2
-45.0
-43.0
-41.0
-47.2
-45.2
-43.2
-47.0
-45.0
-43.0
-49.2
-47.2
-45.2
-47.0
-45.0
-43.0
-49.2
-47.2
-45.2
values (Typ.) can be calculated
- 50.2 + 20log( V
DD
) [dBV]
AMP
5
- 52.2 + 20log( V
DD
) [dBV]
AMP
5
=50pF
L
Min.
Typ.
Max.
20
5
10
15
5
10
15
7
12
10
15
2nd RING
S1C05251 TECHNICAL MANUAL
Unit
msec
Unit
Baud
Hz
Hz
Hz
Hz
dB
dBm
dBV
dBm
dBV
dBm
dBV
dBm
dBV
Unit
msec
msec
msec
msec
msec
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